azul_layout/solver3/

fc.rs

//! solver3/fc.rs - Formatting Context Layout
//!
//! This module implements the CSS Visual Formatting Model's formatting contexts:
//!
//! - **Block Formatting Context (BFC)**: CSS 2.2 § 9.4.1 Block-level boxes in normal flow, with
//!   margin collapsing and float positioning.
//!
//! - **Inline Formatting Context (IFC)**: CSS 2.2 § 9.4.2 Inline-level content (text,
//!   inline-blocks) laid out in line boxes.
//!
//! - **Table Formatting Context**: CSS 2.2 § 17 Table layout with column width calculation and cell
//!   positioning.
//!
//! - **Flex/Grid Formatting Contexts**: CSS Flexbox/Grid via Taffy Delegated to the Taffy layout
//!   engine for modern layout modes.
//!
//! # Module Organization
//!
//! 1. **Constants & Types** - Magic numbers as named constants, core types
//! 2. **Entry Point** - `layout_formatting_context` dispatcher
//! 3. **BFC Layout** - Block formatting context implementation
//! 4. **IFC Layout** - Inline formatting context implementation
//! 5. **Table Layout** - Table formatting context implementation
//! 6. **Flex/Grid Layout** - Taffy bridge wrappers
//! 7. **Helper Functions** - Property getters, margin collapsing, utilities

use std::{
    collections::{BTreeMap, HashMap},
    sync::Arc,
};

use azul_core::{
    dom::{FormattingContext, NodeId, NodeType},
    geom::{LogicalPosition, LogicalRect, LogicalSize},
    resources::RendererResources,
    styled_dom::{StyledDom, StyledNodeState},
};
use azul_css::{
    css::CssPropertyValue,
    props::{
        basic::{
            font::{StyleFontStyle, StyleFontWeight},
            pixel::{DEFAULT_FONT_SIZE, PT_TO_PX},
            ColorU, PhysicalSize, PropertyContext, ResolutionContext, SizeMetric,
        },
        layout::{
            ColumnCount, LayoutBorderSpacing, LayoutClear, LayoutDisplay, LayoutFloat,
            LayoutHeight, LayoutJustifyContent, LayoutOverflow, LayoutPosition, LayoutTableLayout,
            LayoutTextJustify, LayoutWidth, LayoutWritingMode, ShapeInside, ShapeOutside,
            StyleBorderCollapse, StyleCaptionSide,
        },
        property::CssProperty,
        style::{
            BorderStyle, StyleDirection, StyleHyphens, StyleListStylePosition, StyleListStyleType,
            StyleTextAlign, StyleTextCombineUpright, StyleVerticalAlign, StyleVisibility,
            StyleWhiteSpace,
        },
    },
};
use rust_fontconfig::FcWeight;
use taffy::{AvailableSpace, LayoutInput, Line, Size as TaffySize};

#[cfg(feature = "text_layout")]
use crate::text3;
use crate::{
    debug_ifc_layout, debug_info, debug_log, debug_table_layout, debug_warning,
    font_traits::{
        ContentIndex, FontLoaderTrait, ImageSource, InlineContent, InlineImage, InlineShape,
        LayoutFragment, ObjectFit, ParsedFontTrait, SegmentAlignment, ShapeBoundary,
        ShapeDefinition, ShapedItem, Size, StyleProperties, StyledRun, TextLayoutCache,
        UnifiedConstraints,
    },
    solver3::{
        geometry::{BoxProps, EdgeSizes, IntrinsicSizes},
        getters::{
            get_css_height, get_css_width, get_display_property, get_element_font_size, get_float,
            get_list_style_position, get_list_style_type, get_overflow_x, get_overflow_y,
            get_parent_font_size, get_root_font_size, get_style_properties, get_writing_mode,
            MultiValue,
        },
        layout_tree::{
            AnonymousBoxType, CachedInlineLayout, LayoutNode, LayoutTree, PseudoElement,
        },
        positioning::get_position_type,
        scrollbar::ScrollbarRequirements,
        sizing::extract_text_from_node,
        taffy_bridge, LayoutContext, LayoutDebugMessage, LayoutError, Result,
    },
    text3::cache::{AvailableSpace as Text3AvailableSpace, TextAlign as Text3TextAlign},
};

/// Default scrollbar width in pixels (CSS Overflow Module Level 3).
/// Used when `overflow: scroll` or `overflow: auto` triggers scrollbar display.
pub const SCROLLBAR_WIDTH_PX: f32 = 16.0;

// Note: DEFAULT_FONT_SIZE and PT_TO_PX are imported from pixel

/// Result of BFC layout with margin escape information
#[derive(Debug, Clone)]
pub(crate) struct BfcLayoutResult {
    /// Standard layout output (positions, overflow size, baseline)
    pub output: LayoutOutput,
    /// Top margin that escaped the BFC (for parent-child collapse)
    /// If Some, this margin should be used by parent instead of positioning this BFC
    pub escaped_top_margin: Option<f32>,
    /// Bottom margin that escaped the BFC (for parent-child collapse)
    /// If Some, this margin should collapse with next sibling
    pub escaped_bottom_margin: Option<f32>,
}

impl BfcLayoutResult {
    pub fn from_output(output: LayoutOutput) -> Self {
        Self {
            output,
            escaped_top_margin: None,
            escaped_bottom_margin: None,
        }
    }
}

/// The CSS `overflow` property behavior.
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub enum OverflowBehavior {
    Visible,
    Hidden,
    Clip,
    Scroll,
    Auto,
}

impl OverflowBehavior {
    pub fn is_clipped(&self) -> bool {
        matches!(self, Self::Hidden | Self::Clip | Self::Scroll | Self::Auto)
    }

    pub fn is_scroll(&self) -> bool {
        matches!(self, Self::Scroll | Self::Auto)
    }
}

/// Input constraints for a layout function.
#[derive(Debug)]
pub struct LayoutConstraints<'a> {
    /// The available space for the content, excluding padding and borders.
    pub available_size: LogicalSize,
    /// The CSS writing-mode of the context.
    pub writing_mode: LayoutWritingMode,
    /// The state of the parent Block Formatting Context, if applicable.
    /// This is how state (like floats) is passed down.
    pub bfc_state: Option<&'a mut BfcState>,
    // Other properties like text-align would go here.
    pub text_align: TextAlign,
    /// The size of the containing block (parent's content box).
    /// This is used for resolving percentage-based sizes and as parent_size for Taffy.
    pub containing_block_size: LogicalSize,
    /// The semantic type of the available width constraint.
    ///
    /// This field is crucial for correct inline layout caching:
    /// - `Definite(w)`: Normal layout with a specific available width
    /// - `MinContent`: Intrinsic minimum width measurement (maximum wrapping)
    /// - `MaxContent`: Intrinsic maximum width measurement (no wrapping)
    ///
    /// When caching inline layouts, we must track which constraint type was used
    /// to compute the cached result. A layout computed with `MinContent` (width=0)
    /// must not be reused when the actual available width is known.
    pub available_width_type: Text3AvailableSpace,
}

/// Manages all layout state for a single Block Formatting Context.
/// This struct is created by the BFC root and lives for the duration of its layout.
#[derive(Debug, Clone)]
pub struct BfcState {
    /// The current position for the next in-flow block element.
    pub pen: LogicalPosition,
    /// The state of all floated elements within this BFC.
    pub floats: FloatingContext,
    /// The state of margin collapsing within this BFC.
    pub margins: MarginCollapseContext,
}

impl BfcState {
    pub fn new() -> Self {
        Self {
            pen: LogicalPosition::zero(),
            floats: FloatingContext::default(),
            margins: MarginCollapseContext::default(),
        }
    }
}

/// Manages vertical margin collapsing within a BFC.
#[derive(Debug, Default, Clone)]
pub struct MarginCollapseContext {
    /// The bottom margin of the last in-flow, block-level element.
    /// Can be positive or negative.
    pub last_in_flow_margin_bottom: f32,
}

/// The result of laying out a formatting context.
#[derive(Debug, Default, Clone)]
pub struct LayoutOutput {
    /// The final positions of child nodes, relative to the container's content-box origin.
    pub positions: BTreeMap<usize, LogicalPosition>,
    /// The total size occupied by the content, which may exceed `available_size`.
    pub overflow_size: LogicalSize,
    /// The baseline of the context, if applicable, measured from the top of its content box.
    pub baseline: Option<f32>,
}

/// Text alignment options
#[derive(Debug, Clone, Copy, Default)]
pub enum TextAlign {
    #[default]
    Start,
    End,
    Center,
    Justify,
}

/// Represents a single floated element within a BFC.
#[derive(Debug, Clone, Copy)]
struct FloatBox {
    /// The type of float (Left or Right).
    kind: LayoutFloat,
    /// The rectangle of the float's content box (origin includes top/left margin offset).
    rect: LogicalRect,
    /// The margin sizes (needed to calculate true margin-box bounds).
    margin: EdgeSizes,
}

/// Manages the state of all floated elements within a Block Formatting Context.
#[derive(Debug, Default, Clone)]
pub struct FloatingContext {
    /// All currently positioned floats within the BFC.
    pub floats: Vec<FloatBox>,
}

impl FloatingContext {
    /// Add a newly positioned float to the context
    pub fn add_float(&mut self, kind: LayoutFloat, rect: LogicalRect, margin: EdgeSizes) {
        self.floats.push(FloatBox { kind, rect, margin });
    }

    /// Finds the available space on the cross-axis for a line box at a given main-axis range.
    ///
    /// Returns a tuple of (`cross_start_offset`, `cross_end_offset`) relative to the
    /// BFC content box, defining the available space for an in-flow element.
    pub fn available_line_box_space(
        &self,
        main_start: f32,
        main_end: f32,
        bfc_cross_size: f32,
        wm: LayoutWritingMode,
    ) -> (f32, f32) {
        let mut available_cross_start = 0.0_f32;
        let mut available_cross_end = bfc_cross_size;

        for float in &self.floats {
            // Get the logical main-axis span of the existing float.
            let float_main_start = float.rect.origin.main(wm);
            let float_main_end = float_main_start + float.rect.size.main(wm);

            // Check for overlap on the main axis.
            if main_end > float_main_start && main_start < float_main_end {
                // The float overlaps with the main-axis range of the element we're placing.
                let float_cross_start = float.rect.origin.cross(wm);
                let float_cross_end = float_cross_start + float.rect.size.cross(wm);

                if float.kind == LayoutFloat::Left {
                    // "line-left", i.e., cross-start
                    available_cross_start = available_cross_start.max(float_cross_end);
                } else {
                    // Float::Right, i.e., cross-end
                    available_cross_end = available_cross_end.min(float_cross_start);
                }
            }
        }
        (available_cross_start, available_cross_end)
    }

    /// Returns the main-axis offset needed to be clear of floats of the given type.
    pub fn clearance_offset(
        &self,
        clear: LayoutClear,
        current_main_offset: f32,
        wm: LayoutWritingMode,
    ) -> f32 {
        let mut max_end_offset = 0.0_f32;

        let check_left = clear == LayoutClear::Left || clear == LayoutClear::Both;
        let check_right = clear == LayoutClear::Right || clear == LayoutClear::Both;

        for float in &self.floats {
            let should_clear_this_float = (check_left && float.kind == LayoutFloat::Left)
                || (check_right && float.kind == LayoutFloat::Right);

            if should_clear_this_float {
                // CSS 2.2 § 9.5.2: "the top border edge of the box be below the bottom outer edge"
                // Outer edge = margin-box boundary (content + padding + border + margin)
                let float_margin_box_end = float.rect.origin.main(wm)
                    + float.rect.size.main(wm)
                    + float.margin.main_end(wm);
                max_end_offset = max_end_offset.max(float_margin_box_end);
            }
        }

        if max_end_offset > current_main_offset {
            max_end_offset
        } else {
            current_main_offset
        }
    }
}

/// Encapsulates all state needed to lay out a single Block Formatting Context.
struct BfcLayoutState {
    /// The current position for the next in-flow block element.
    pen: LogicalPosition,
    floats: FloatingContext,
    margins: MarginCollapseContext,
    /// The writing mode of the BFC root.
    writing_mode: LayoutWritingMode,
}

/// Result of a formatting context layout operation
#[derive(Debug, Default)]
pub struct LayoutResult {
    pub positions: Vec<(usize, LogicalPosition)>,
    pub overflow_size: Option<LogicalSize>,
    pub baseline_offset: f32,
}

// Entry Point & Dispatcher

/// Main dispatcher for formatting context layout.
///
/// Routes layout to the appropriate formatting context handler based on the node's
/// `formatting_context` property. This is the main entry point for all layout operations.
///
/// # CSS Spec References
/// - CSS 2.2 § 9.4: Formatting contexts
/// - CSS Flexbox § 3: Flex formatting contexts
/// - CSS Grid § 5: Grid formatting contexts
pub fn layout_formatting_context<T: ParsedFontTrait>(
    ctx: &mut LayoutContext<'_, T>,
    tree: &mut LayoutTree,
    text_cache: &mut crate::font_traits::TextLayoutCache,
    node_index: usize,
    constraints: &LayoutConstraints,
    float_cache: &mut std::collections::BTreeMap<usize, FloatingContext>,
) -> Result<BfcLayoutResult> {
    let node = tree.get(node_index).ok_or(LayoutError::InvalidTree)?;

    debug_info!(
        ctx,
        "[layout_formatting_context] node_index={}, fc={:?}, available_size={:?}",
        node_index,
        node.formatting_context,
        constraints.available_size
    );

    match node.formatting_context {
        FormattingContext::Block { .. } => {
            layout_bfc(ctx, tree, text_cache, node_index, constraints, float_cache)
        }
        FormattingContext::Inline => layout_ifc(ctx, text_cache, tree, node_index, constraints)
            .map(BfcLayoutResult::from_output),
        FormattingContext::Table => layout_table_fc(ctx, tree, text_cache, node_index, constraints)
            .map(BfcLayoutResult::from_output),
        FormattingContext::Flex | FormattingContext::Grid => {
            layout_flex_grid(ctx, tree, text_cache, node_index, constraints)
        }
        _ => {
            // Unknown formatting context - fall back to BFC
            let mut temp_float_cache = std::collections::BTreeMap::new();
            layout_bfc(
                ctx,
                tree,
                text_cache,
                node_index,
                constraints,
                &mut temp_float_cache,
            )
        }
    }
}

// Flex / grid layout (taffy Bridge)

/// Lays out a Flex or Grid formatting context using the Taffy layout engine.
///
/// # CSS Spec References
///
/// - CSS Flexbox § 9: Flex Layout Algorithm
/// - CSS Grid § 12: Grid Layout Algorithm
///
/// # Implementation Notes
///
/// - Resolves explicit CSS dimensions to pixel values for `known_dimensions`
/// - Uses `InherentSize` mode when explicit dimensions are set
/// - Uses `ContentSize` mode for auto-sizing (shrink-to-fit)
fn layout_flex_grid<T: ParsedFontTrait>(
    ctx: &mut LayoutContext<'_, T>,
    tree: &mut LayoutTree,
    text_cache: &mut crate::font_traits::TextLayoutCache,
    node_index: usize,
    constraints: &LayoutConstraints,
) -> Result<BfcLayoutResult> {
    let available_space = TaffySize {
        width: AvailableSpace::Definite(constraints.available_size.width),
        height: AvailableSpace::Definite(constraints.available_size.height),
    };

    let node = tree.get(node_index).ok_or(LayoutError::InvalidTree)?;

    // Resolve explicit CSS dimensions to pixel values.
    // This is CRITICAL for align-items: stretch to work correctly!
    // Taffy uses known_dimensions to calculate cross_axis_available_space for children.
    let (explicit_width, has_explicit_width) =
        resolve_explicit_dimension_width(ctx, node, constraints);
    let (explicit_height, has_explicit_height) =
        resolve_explicit_dimension_height(ctx, node, constraints);

    // FIX: Taffy interprets known_dimensions as Border Box size.
    // CSS width/height properties define Content Box size (by default, box-sizing: content-box).
    // We must add border and padding to the explicit dimensions to get the correct Border
    // Box size for Taffy.
    let width_adjustment = node.box_props.border.left
        + node.box_props.border.right
        + node.box_props.padding.left
        + node.box_props.padding.right;
    let height_adjustment = node.box_props.border.top
        + node.box_props.border.bottom
        + node.box_props.padding.top
        + node.box_props.padding.bottom;

    // Apply adjustment only if dimensions are explicit (convert content-box to border-box)
    let adjusted_width = explicit_width.map(|w| w + width_adjustment);
    let adjusted_height = explicit_height.map(|h| h + height_adjustment);

    // CSS Flexbox § 9.2: Use InherentSize when explicit dimensions are set,
    // ContentSize for auto-sizing (shrink-to-fit behavior).
    let sizing_mode = if has_explicit_width || has_explicit_height {
        taffy::SizingMode::InherentSize
    } else {
        taffy::SizingMode::ContentSize
    };

    let known_dimensions = TaffySize {
        width: adjusted_width,
        height: adjusted_height,
    };

    let taffy_inputs = LayoutInput {
        known_dimensions,
        parent_size: translate_taffy_size(constraints.containing_block_size),
        available_space,
        run_mode: taffy::RunMode::PerformLayout,
        sizing_mode,
        axis: taffy::RequestedAxis::Both,
        // Flex and Grid containers establish a new BFC, preventing margin collapse.
        vertical_margins_are_collapsible: Line::FALSE,
    };

    debug_info!(
        ctx,
        "CALLING LAYOUT_TAFFY FOR FLEX/GRID FC node_index={:?}",
        node_index
    );

    let taffy_output =
        taffy_bridge::layout_taffy_subtree(ctx, tree, text_cache, node_index, taffy_inputs);

    // Collect child positions from the tree (Taffy stores results directly on nodes).
    let mut output = LayoutOutput::default();
    // Use content_size for overflow detection, not container size.
    // content_size represents the actual size of all children, which may exceed the container.
    output.overflow_size = translate_taffy_size_back(taffy_output.content_size);

    let children: Vec<usize> = tree.get(node_index).unwrap().children.clone();
    for &child_idx in &children {
        if let Some(child_node) = tree.get(child_idx) {
            if let Some(pos) = child_node.relative_position {
                output.positions.insert(child_idx, pos);
            }
        }
    }

    Ok(BfcLayoutResult::from_output(output))
}

/// Resolves explicit CSS width to pixel value for Taffy layout.
fn resolve_explicit_dimension_width<T: ParsedFontTrait>(
    ctx: &LayoutContext<'_, T>,
    node: &LayoutNode,
    constraints: &LayoutConstraints,
) -> (Option<f32>, bool) {
    node.dom_node_id
        .map(|id| {
            let width = get_css_width(
                ctx.styled_dom,
                id,
                &ctx.styled_dom.styled_nodes.as_container()[id].styled_node_state,
            );
            match width.unwrap_or_default() {
                LayoutWidth::Auto => (None, false),
                LayoutWidth::Px(px) => {
                    let pixels = resolve_size_metric(
                        px.metric,
                        px.number.get(),
                        constraints.available_size.width,
                    );
                    (Some(pixels), true)
                }
                LayoutWidth::MinContent | LayoutWidth::MaxContent => (None, false),
            }
        })
        .unwrap_or((None, false))
}

/// Resolves explicit CSS height to pixel value for Taffy layout.
fn resolve_explicit_dimension_height<T: ParsedFontTrait>(
    ctx: &LayoutContext<'_, T>,
    node: &LayoutNode,
    constraints: &LayoutConstraints,
) -> (Option<f32>, bool) {
    node.dom_node_id
        .map(|id| {
            let height = get_css_height(
                ctx.styled_dom,
                id,
                &ctx.styled_dom.styled_nodes.as_container()[id].styled_node_state,
            );
            match height.unwrap_or_default() {
                LayoutHeight::Auto => (None, false),
                LayoutHeight::Px(px) => {
                    let pixels = resolve_size_metric(
                        px.metric,
                        px.number.get(),
                        constraints.available_size.height,
                    );
                    (Some(pixels), true)
                }
                LayoutHeight::MinContent | LayoutHeight::MaxContent => (None, false),
            }
        })
        .unwrap_or((None, false))
}

/// Position a float within a BFC, considering existing floats.
/// Returns the LogicalRect (margin box) for the float.
fn position_float(
    float_ctx: &FloatingContext,
    float_type: LayoutFloat,
    size: LogicalSize,
    margin: &EdgeSizes,
    current_main_offset: f32,
    bfc_cross_size: f32,
    wm: LayoutWritingMode,
) -> LogicalRect {
    // Start at the current main-axis position (Y in horizontal-tb)
    let mut main_start = current_main_offset;

    // Calculate total size including margins
    let total_main = size.main(wm) + margin.main_start(wm) + margin.main_end(wm);
    let total_cross = size.cross(wm) + margin.cross_start(wm) + margin.cross_end(wm);

    // Find a position where the float fits
    let cross_start = loop {
        let (avail_start, avail_end) = float_ctx.available_line_box_space(
            main_start,
            main_start + total_main,
            bfc_cross_size,
            wm,
        );

        let available_width = avail_end - avail_start;

        if available_width >= total_cross {
            // Found space that fits
            if float_type == LayoutFloat::Left {
                // Position at line-left (avail_start)
                break avail_start + margin.cross_start(wm);
            } else {
                // Position at line-right (avail_end - size)
                break avail_end - total_cross + margin.cross_start(wm);
            }
        }

        // Not enough space at this Y, move down past the lowest overlapping float
        let next_main = float_ctx
            .floats
            .iter()
            .filter(|f| {
                let f_main_start = f.rect.origin.main(wm);
                let f_main_end = f_main_start + f.rect.size.main(wm);
                f_main_end > main_start && f_main_start < main_start + total_main
            })
            .map(|f| f.rect.origin.main(wm) + f.rect.size.main(wm))
            .max_by(|a, b| a.partial_cmp(b).unwrap());

        if let Some(next) = next_main {
            main_start = next;
        } else {
            // No overlapping floats found, use current position anyway
            if float_type == LayoutFloat::Left {
                break avail_start + margin.cross_start(wm);
            } else {
                break avail_end - total_cross + margin.cross_start(wm);
            }
        }
    };

    LogicalRect {
        origin: LogicalPosition::from_main_cross(
            main_start + margin.main_start(wm),
            cross_start,
            wm,
        ),
        size,
    }
}

// Block Formatting Context (CSS 2.2 § 9.4.1)

/// Lays out a Block Formatting Context (BFC).
///
/// This is the corrected, architecturally-sound implementation. It solves the
/// "chicken-and-egg" problem by performing its own two-pass layout:
///
/// 1. **Sizing Pass:** It first iterates through its children and triggers their layout recursively
///    by calling `calculate_layout_for_subtree`. This ensures that the `used_size` property of each
///    child is correctly populated.
///
/// 2. **Positioning Pass:** It then iterates through the children again. Now that each child has a
///    valid size, it can apply the standard block-flow logic: stacking them vertically and
///    advancing a "pen" by each child's outer height.
///
/// # Margin Collapsing Architecture
///
/// CSS 2.1 Section 8.3.1 compliant margin collapsing:
///
/// ```text
/// layout_bfc()
///   ├─ Check parent border/padding blockers
///   ├─ For each child:
///   │   ├─ Check child border/padding blockers
///   │   ├─ is_first_child?
///   │   │   └─ Check parent-child top collapse
///   │   ├─ Sibling collapse?
///   │   │   └─ advance_pen_with_margin_collapse()
///   │   │       └─ collapse_margins(prev_bottom, curr_top)
///   │   ├─ Position child
///   │   ├─ is_empty_block()?
///   │   │   └─ Collapse own top+bottom margins (collapse through)
///   │   └─ Save bottom margin for next sibling
///   └─ Check parent-child bottom collapse
/// ```
///
/// **Collapsing Rules:**
///
/// - Sibling margins: Adjacent vertical margins collapse to max (or sum if mixed signs)
/// - Parent-child: First child's top margin can escape parent (if no border/padding)
/// - Parent-child: Last child's bottom margin can escape parent (if no border/padding/height)
/// - Empty blocks: Top+bottom margins collapse with each other, then with siblings
/// - Blockers: Border, padding, inline content, or new BFC prevents collapsing
///
/// This approach is compliant with the CSS visual formatting model and works within
/// the constraints of the existing layout engine architecture.
fn layout_bfc<T: ParsedFontTrait>(
    ctx: &mut LayoutContext<'_, T>,
    tree: &mut LayoutTree,
    text_cache: &mut crate::font_traits::TextLayoutCache,
    node_index: usize,
    constraints: &LayoutConstraints,
    float_cache: &mut std::collections::BTreeMap<usize, FloatingContext>,
) -> Result<BfcLayoutResult> {
    let node = tree
        .get(node_index)
        .ok_or(LayoutError::InvalidTree)?
        .clone();
    let writing_mode = constraints.writing_mode;
    let mut output = LayoutOutput::default();

    debug_info!(
        ctx,
        "\n[layout_bfc] ENTERED for node_index={}, children.len()={}, incoming_bfc_state={}",
        node_index,
        node.children.len(),
        constraints.bfc_state.is_some()
    );

    // Initialize FloatingContext for this BFC
    //
    // We always recalculate float positions in this pass, but we'll store them in the cache
    // so that subsequent layout passes (for auto-sizing) have access to the positioned floats
    let mut float_context = FloatingContext::default();

    // Calculate this node's content-box size for use as containing block for children
    // CSS 2.2 § 10.1: The containing block for in-flow children is formed by the
    // content edge of the parent's content box.
    //
    // We use constraints.available_size directly as this already represents the
    // content-box available to this node (set by parent). For nodes with explicit
    // sizes, used_size contains the border-box which we convert to content-box.
    let mut children_containing_block_size = if let Some(used_size) = node.used_size {
        // Node has explicit used_size (border-box) - convert to content-box
        node.box_props.inner_size(used_size, writing_mode)
    } else {
        // No used_size yet - use available_size directly (this is already content-box
        // when coming from parent's layout constraints)
        constraints.available_size
    };

    // Proactively reserve space for vertical scrollbar if overflow-y is auto/scroll.
    // This ensures children are laid out with the correct available width from the start,
    // preventing the "children overlap scrollbar" layout issue.
    let scrollbar_reservation = node
        .dom_node_id
        .map(|dom_id| {
            let styled_node_state = ctx
                .styled_dom
                .styled_nodes
                .as_container()
                .get(dom_id)
                .map(|s| s.styled_node_state.clone())
                .unwrap_or_default();
            let overflow_y =
                crate::solver3::getters::get_overflow_y(ctx.styled_dom, dom_id, &styled_node_state);
            use azul_css::props::layout::LayoutOverflow;
            match overflow_y.unwrap_or_default() {
                LayoutOverflow::Scroll | LayoutOverflow::Auto => SCROLLBAR_WIDTH_PX,
                _ => 0.0,
            }
        })
        .unwrap_or(0.0);

    if scrollbar_reservation > 0.0 {
        children_containing_block_size.width =
            (children_containing_block_size.width - scrollbar_reservation).max(0.0);
    }

    // Pass 1: Size all children (floats and normal flow)
    for &child_index in &node.children {
        let child_node = tree.get(child_index).ok_or(LayoutError::InvalidTree)?;
        let child_dom_id = child_node.dom_node_id;

        // Skip out-of-flow children (absolute/fixed)
        let position_type = get_position_type(ctx.styled_dom, child_dom_id);
        if position_type == LayoutPosition::Absolute || position_type == LayoutPosition::Fixed {
            continue;
        }

        // Size all children (floats and normal flow) - floats will be positioned later in Pass 2
        let mut temp_positions = BTreeMap::new();
        crate::solver3::cache::calculate_layout_for_subtree(
            ctx,
            tree,
            text_cache,
            child_index,
            LogicalPosition::zero(),
            children_containing_block_size, // Use this node's content-box as containing block
            &mut temp_positions,
            &mut bool::default(),
            float_cache,
        )?;
    }

    // Pass 2: Single-pass interleaved layout (position floats and normal flow in DOM order)

    let mut main_pen = 0.0f32;
    let mut max_cross_size = 0.0f32;

    // Track escaped margins separately from content-box height
    // CSS 2.2 § 8.3.1: Escaped margins don't contribute to parent's content-box height,
    // but DO affect sibling positioning within the parent
    let mut total_escaped_top_margin = 0.0f32;
    // Track all inter-sibling margins (collapsed) - these are also not part of content height
    let mut total_sibling_margins = 0.0f32;

    // Margin collapsing state
    let mut last_margin_bottom = 0.0f32;
    let mut is_first_child = true;
    let mut first_child_index: Option<usize> = None;
    let mut last_child_index: Option<usize> = None;

    // Parent's own margins (for escape calculation)
    let parent_margin_top = node.box_props.margin.main_start(writing_mode);
    let parent_margin_bottom = node.box_props.margin.main_end(writing_mode);

    // Check if parent (this BFC root) has border/padding that prevents parent-child collapse
    let parent_has_top_blocker = has_margin_collapse_blocker(&node.box_props, writing_mode, true);
    let parent_has_bottom_blocker =
        has_margin_collapse_blocker(&node.box_props, writing_mode, false);

    // Track accumulated top margin for first-child escape
    let mut accumulated_top_margin = 0.0f32;
    let mut top_margin_resolved = false;
    // Track if first child's margin escaped (for return value)
    let mut top_margin_escaped = false;

    // Track if we have any actual content (non-empty blocks)
    let mut has_content = false;

    for &child_index in &node.children {
        let child_node = tree.get(child_index).ok_or(LayoutError::InvalidTree)?;
        let child_dom_id = child_node.dom_node_id;

        let position_type = get_position_type(ctx.styled_dom, child_dom_id);
        if position_type == LayoutPosition::Absolute || position_type == LayoutPosition::Fixed {
            continue;
        }

        // Check if this child is a float - if so, position it at current main_pen
        let is_float = if let Some(node_id) = child_dom_id {
            let float_type = get_float_property(ctx.styled_dom, Some(node_id));

            if float_type != LayoutFloat::None {
                let float_size = child_node.used_size.unwrap_or_default();
                let float_margin = &child_node.box_props.margin;

                // CSS 2.2 § 9.5: Float margins don't collapse with any other margins.
                // If there's a previous in-flow element with a bottom margin, we must
                // include it in the Y position calculation for this float.
                let float_y = main_pen + last_margin_bottom;

                debug_info!(
                    ctx,
                    "[layout_bfc] Positioning float: index={}, type={:?}, size={:?}, at Y={} \
                     (main_pen={} + last_margin={})",
                    child_index,
                    float_type,
                    float_size,
                    float_y,
                    main_pen,
                    last_margin_bottom
                );

                // Position the float at the CURRENT main_pen + last margin (respects DOM order!)
                let float_rect = position_float(
                    &float_context,
                    float_type,
                    float_size,
                    float_margin,
                    // Include last_margin_bottom since float margins don't collapse!
                    float_y,
                    constraints.available_size.cross(writing_mode),
                    writing_mode,
                );

                debug_info!(ctx, "[layout_bfc] Float positioned at: {:?}", float_rect);

                // Add to float context BEFORE positioning next element
                float_context.add_float(float_type, float_rect, *float_margin);

                // Store position in output
                output.positions.insert(child_index, float_rect.origin);

                debug_info!(
                    ctx,
                    "[layout_bfc] *** FLOAT POSITIONED: child={}, main_pen={} (unchanged - floats \
                     don't advance pen)",
                    child_index,
                    main_pen
                );

                // Floats are taken out of normal flow - DON'T advance main_pen
                // Continue to next child
                continue;
            }
            false
        } else {
            false
        };

        // Early exit for floats (already handled above)
        if is_float {
            continue;
        }

        // From here: normal flow (non-float) children only

        // Track first and last in-flow children for parent-child collapse
        if first_child_index.is_none() {
            first_child_index = Some(child_index);
        }
        last_child_index = Some(child_index);

        let child_size = child_node.used_size.unwrap_or_default();
        let child_margin = &child_node.box_props.margin;

        debug_info!(
            ctx,
            "[layout_bfc] Child {} margin from box_props: top={}, right={}, bottom={}, left={}",
            child_index,
            child_margin.top,
            child_margin.right,
            child_margin.bottom,
            child_margin.left
        );

        // IMPORTANT: Use the ACTUAL margins from box_props, NOT escaped margins!
        //
        // Escaped margins are only relevant for the parent-child relationship WITHIN a node's
        // own BFC layout. When positioning this child in ITS parent's BFC, we use its actual
        // margins. CSS 2.2 § 8.3.1: Margin collapsing happens between ADJACENT margins,
        // which means:
        //
        // - Parent's top and first child's top (if no blocker)
        // - Sibling's bottom and next sibling's top
        // - Parent's bottom and last child's bottom (if no blocker)
        //
        // The escaped_top_margin stored in the child node is for its OWN children, not for itself!
        let child_margin_top = child_margin.main_start(writing_mode);
        let child_margin_bottom = child_margin.main_end(writing_mode);

        debug_info!(
            ctx,
            "[layout_bfc] Child {} final margins: margin_top={}, margin_bottom={}",
            child_index,
            child_margin_top,
            child_margin_bottom
        );

        // Check if this child has border/padding that prevents margin collapsing
        let child_has_top_blocker =
            has_margin_collapse_blocker(&child_node.box_props, writing_mode, true);
        let child_has_bottom_blocker =
            has_margin_collapse_blocker(&child_node.box_props, writing_mode, false);

        // Check for clear property FIRST - clearance affects whether element is considered empty
        // CSS 2.2 § 9.5.2: "Clearance inhibits margin collapsing"
        // An element with clearance is NOT empty even if it has no content
        let child_clear = if let Some(node_id) = child_dom_id {
            get_clear_property(ctx.styled_dom, Some(node_id))
        } else {
            LayoutClear::None
        };
        debug_info!(
            ctx,
            "[layout_bfc] Child {} clear property: {:?}",
            child_index,
            child_clear
        );

        // PHASE 1: Empty Block Detection & Self-Collapse
        let is_empty = is_empty_block(child_node);

        // Handle empty blocks FIRST (they collapse through and don't participate in layout)
        // EXCEPTION: Elements with clear property are NOT skipped even if empty!
        // CSS 2.2 § 9.5.2: Clear property affects positioning even for empty elements
        if is_empty
            && !child_has_top_blocker
            && !child_has_bottom_blocker
            && child_clear == LayoutClear::None
        {
            // Empty block: collapse its own top and bottom margins FIRST
            let self_collapsed = collapse_margins(child_margin_top, child_margin_bottom);

            // Then collapse with previous margin (sibling or parent)
            if is_first_child {
                is_first_child = false;
                // Empty first child: its collapsed margin can escape with parent's
                if !parent_has_top_blocker {
                    accumulated_top_margin = collapse_margins(parent_margin_top, self_collapsed);
                } else {
                    // Parent has blocker: add margins
                    if accumulated_top_margin == 0.0 {
                        accumulated_top_margin = parent_margin_top;
                    }
                    main_pen += accumulated_top_margin + self_collapsed;
                    top_margin_resolved = true;
                    accumulated_top_margin = 0.0;
                }
                last_margin_bottom = self_collapsed;
            } else {
                // Empty sibling: collapse with previous sibling's bottom margin
                last_margin_bottom = collapse_margins(last_margin_bottom, self_collapsed);
            }

            // Skip positioning and pen advance (empty has no visual presence)
            continue;
        }

        // From here on: non-empty blocks only (or empty blocks with clear property)

        // Apply clearance if needed
        // CSS 2.2 § 9.5.2: Clearance inhibits margin collapsing
        let clearance_applied = if child_clear != LayoutClear::None {
            let cleared_offset =
                float_context.clearance_offset(child_clear, main_pen, writing_mode);
            debug_info!(
                ctx,
                "[layout_bfc] Child {} clearance check: cleared_offset={}, main_pen={}",
                child_index,
                cleared_offset,
                main_pen
            );
            if cleared_offset > main_pen {
                debug_info!(
                    ctx,
                    "[layout_bfc] Applying clearance: child={}, clear={:?}, old_pen={}, new_pen={}",
                    child_index,
                    child_clear,
                    main_pen,
                    cleared_offset
                );
                main_pen = cleared_offset;
                true // Signal that clearance was applied
            } else {
                false
            }
        } else {
            false
        };

        // PHASE 2: Parent-Child Top Margin Escape (First Child)
        //
        // CSS 2.2 § 8.3.1: "The top margin of a box is adjacent to the top margin of its first
        // in-flow child if the box has no top border, no top padding, and the child has no
        // clearance." CSS 2.2 § 9.5.2: "Clearance inhibits margin collapsing"

        if is_first_child {
            is_first_child = false;

            // Clearance prevents collapse (acts as invisible blocker)
            if clearance_applied {
                // Clearance inhibits all margin collapsing for this element
                // The clearance has already positioned main_pen past floats
                //
                // CSS 2.2 § 8.3.1: Parent's margin was already handled by parent's parent BFC
                // We only add child's margin in our content-box coordinate space
                main_pen += child_margin_top;
                debug_info!(
                    ctx,
                    "[layout_bfc] First child {} with CLEARANCE: no collapse, child_margin={}, \
                     main_pen={}",
                    child_index,
                    child_margin_top,
                    main_pen
                );
            } else if !parent_has_top_blocker {
                // Margin Escape Case
                //
                // CSS 2.2 § 8.3.1: "The top margin of an in-flow block element collapses with
                // its first in-flow block-level child's top margin if the element has no top
                // border, no top padding, and the child has no clearance."
                //
                // When margins collapse, they "escape" upward through the parent to be resolved
                // in the grandparent's coordinate space. This is critical for understanding the
                // coordinate system separation:
                //
                // Example:
                // <body padding=20>
                //  <div margin=0>
                //      <div margin=30></div>
                //  </div>
                // </body>
                //
                //   - Middle div (our parent) has no padding → margins can escape
                //   - Inner div's 30px margin collapses with middle div's 0px margin = 30px
                //   - This 30px margin "escapes" to be handled by body's BFC
                //   - Body positions middle div at Y=30 (relative to body's content-box)
                //   - Middle div's content-box height does NOT include the escaped 30px
                //   - Inner div is positioned at Y=0 in middle div's content-box
                //
                // **NOTE**: This is a subtle but critical distinction in coordinate systems:
                //
                //   - Parent's margin belongs to grandparent's coordinate space
                //   - Child's margin (when escaped) also belongs to grandparent's coordinate space
                //   - They collapse BEFORE entering this BFC's coordinate space
                //   - We return the collapsed margin so grandparent can position parent correctly
                //
                // **NOTE**: Child's own blocker status (padding/border) is IRRELEVANT for
                // parent-child  collapse. The child may have padding that prevents
                // collapse with ITS OWN  children, but this doesn't prevent its
                // margin from escaping  through its parent.
                //
                // **NOTE**: Previously, we incorrectly added parent_margin_top to main_pen in
                //  the blocked case, which double-counted the margin by mixing
                //  coordinate systems. The parent's margin is NEVER in our (the
                //  parent's content-box) coordinate system!

                accumulated_top_margin = collapse_margins(parent_margin_top, child_margin_top);
                top_margin_resolved = true;
                top_margin_escaped = true;

                // Track escaped margin so it gets subtracted from content-box height
                // The escaped margin is NOT part of our content-box - it belongs to our
                // parent's parent
                total_escaped_top_margin = accumulated_top_margin;

                // Position child at pen (no margin applied - it escaped!)
                debug_info!(
                    ctx,
                    "[layout_bfc] First child {} margin ESCAPES: parent_margin={}, \
                     child_margin={}, collapsed={}, total_escaped={}",
                    child_index,
                    parent_margin_top,
                    child_margin_top,
                    accumulated_top_margin,
                    total_escaped_top_margin
                );
            } else {
                // Margin Blocked Case
                //
                // CSS 2.2 § 8.3.1: "no top padding and no top border" required for collapse.
                // When padding or border exists, margins do NOT collapse and exist in different
                // coordinate spaces.
                //
                // CRITICAL COORDINATE SYSTEM SEPARATION:
                //
                //   This is where the architecture becomes subtle. When layout_bfc() is called:
                //   1. We are INSIDE the parent's content-box coordinate space (main_pen starts at
                //      0)
                //   2. The parent's own margin was ALREADY RESOLVED by the grandparent's BFC
                //   3. The parent's margin is in the grandparent's coordinate space, not ours
                //   4. We NEVER reference the parent's margin in this BFC - it's outside our scope
                //
                // Example:
                //
                // <body padding=20>
                //   <div margin=30 padding=20>
                //      <div margin=30></div>
                //   </div>
                // </body>
                //
                //   - Middle div has padding=20 → blocker exists, margins don't collapse
                //   - Body's BFC positions middle div at Y=30 (middle div's margin, in body's
                //     space)
                //   - Middle div's BFC starts at its content-box (after the padding)
                //   - main_pen=0 at the top of middle div's content-box
                //   - Inner div has margin=30 → we add 30 to main_pen (in OUR coordinate space)
                //   - Inner div positioned at Y=30 (relative to middle div's content-box)
                //   - Absolute position: 20 (body padding) + 30 (middle margin) + 20 (middle
                //     padding) + 30 (inner margin) = 100px
                //
                // **NOTE**: Previous code incorrectly added parent_margin_top to main_pen here:
                //
                //     - main_pen += parent_margin_top;  // WRONG! Mixes coordinate systems
                //     - main_pen += child_margin_top;
                //
                //   This caused the "double margin" bug where margins were applied twice:
                //
                //   - Once by grandparent positioning parent (correct)
                //   - Again inside parent's BFC (INCORRECT - wrong coordinate system)
                //
                //   The parent's margin belongs to GRANDPARENT's coordinate space and was already
                //   used to position the parent. Adding it again here is like adding feet to
                //   meters.
                //
                //   We ONLY add the child's margin in our (parent's content-box) coordinate space.
                //   The parent's margin is irrelevant to us - it's outside our scope.

                main_pen += child_margin_top;
                debug_info!(
                    ctx,
                    "[layout_bfc] First child {} BLOCKED: parent_has_blocker={}, advanced by \
                     child_margin={}, main_pen={}",
                    child_index,
                    parent_has_top_blocker,
                    child_margin_top,
                    main_pen
                );
            }
        } else {
            // Not first child: handle sibling collapse
            // CSS 2.2 § 8.3.1 Rule 1: "Vertical margins of adjacent block boxes in the normal flow
            // collapse" CSS 2.2 § 9.5.2: "Clearance inhibits margin collapsing"

            // Resolve accumulated top margin if not yet done (for parent's first in-flow child)
            if !top_margin_resolved {
                main_pen += accumulated_top_margin;
                top_margin_resolved = true;
                debug_info!(
                    ctx,
                    "[layout_bfc] RESOLVED top margin for node {} at sibling {}: accumulated={}, \
                     main_pen={}",
                    node_index,
                    child_index,
                    accumulated_top_margin,
                    main_pen
                );
            }

            if clearance_applied {
                // Clearance inhibits collapsing - add full margin
                main_pen += child_margin_top;
                debug_info!(
                    ctx,
                    "[layout_bfc] Child {} with CLEARANCE: no collapse with sibling, \
                     child_margin_top={}, main_pen={}",
                    child_index,
                    child_margin_top,
                    main_pen
                );
            } else {
                // Sibling Margin Collapse
                //
                // CSS 2.2 § 8.3.1: "Vertical margins of adjacent block boxes in the normal
                // flow collapse." The collapsed margin is the maximum of the two margins.
                //
                // IMPORTANT: Sibling margins ARE part of the parent's content-box height!
                //
                // Unlike escaped margins (which belong to grandparent's space), sibling margins
                // are the space BETWEEN children within our content-box.
                //
                // Example:
                //
                // <div>
                //  <div margin-bottom=30></div>
                //  <div margin-top=40></div>
                // </div>
                //
                //   - First child ends at Y=100 (including its content + margins)
                //   - Collapsed margin = max(30, 40) = 40px
                //   - Second child starts at Y=140 (100 + 40)
                //   - Parent's content-box height includes this 40px gap
                //
                // We track total_sibling_margins for debugging, but NOTE: we do **not**
                // subtract these from content-box height! They are part of the layout space.
                //
                // Previously we subtracted total_sibling_margins from content-box height:
                //
                //   content_box_height = main_pen - total_escaped_top_margin -
                // total_sibling_margins;
                //
                // This was wrong because sibling margins are between boxes (part of content),
                // not outside boxes (like escaped margins).

                let collapsed = collapse_margins(last_margin_bottom, child_margin_top);
                main_pen += collapsed;
                total_sibling_margins += collapsed;
                debug_info!(
                    ctx,
                    "[layout_bfc] Sibling collapse for child {}: last_margin_bottom={}, \
                     child_margin_top={}, collapsed={}, main_pen={}, total_sibling_margins={}",
                    child_index,
                    last_margin_bottom,
                    child_margin_top,
                    collapsed,
                    main_pen,
                    total_sibling_margins
                );
            }
        }

        // Position child (non-empty blocks only reach here)
        //
        // CSS 2.2 § 9.4.1: "In a block formatting context, each box's left outer edge touches
        // the left edge of the containing block (for right-to-left formatting, right edges touch).
        // This is true even in the presence of floats (although a box's line boxes may shrink
        // due to the floats), unless the box establishes a new block formatting context
        // (in which case the box itself may become narrower due to the floats)."
        //
        // CSS 2.2 § 9.5: "The border box of a table, a block-level replaced element, or an element
        // in the normal flow that establishes a new block formatting context (such as an element
        // with 'overflow' other than 'visible') must not overlap any floats in the same block
        // formatting context as the element itself."

        let child_node = tree.get(child_index).ok_or(LayoutError::InvalidTree)?;
        let establishes_bfc = establishes_new_bfc(ctx, child_node);

        // Query available space considering floats ONLY if child establishes new BFC
        let (cross_start, cross_end, available_cross) = if establishes_bfc {
            // New BFC: Must shrink or move down to avoid overlapping floats
            let (start, end) = float_context.available_line_box_space(
                main_pen,
                main_pen + child_size.main(writing_mode),
                constraints.available_size.cross(writing_mode),
                writing_mode,
            );
            let available = end - start;

            debug_info!(
                ctx,
                "[layout_bfc] Child {} establishes BFC: shrinking to avoid floats, \
                 cross_range={}..{}, available_cross={}",
                child_index,
                start,
                end,
                available
            );

            (start, end, available)
        } else {
            // Normal flow: Overlaps floats, positioned at full width
            // Only the child's INLINE CONTENT (if any) wraps around floats
            let start = 0.0;
            let end = constraints.available_size.cross(writing_mode);
            let available = end - start;

            debug_info!(
                ctx,
                "[layout_bfc] Child {} is normal flow: overlapping floats at full width, \
                 available_cross={}",
                child_index,
                available
            );

            (start, end, available)
        };

        // Get child's margin and formatting context
        let (child_margin_cloned, is_inline_fc) = {
            let child_node = tree.get(child_index).ok_or(LayoutError::InvalidTree)?;
            (
                child_node.box_props.margin.clone(),
                child_node.formatting_context == FormattingContext::Inline,
            )
        };
        let child_margin = &child_margin_cloned;

        // Position child
        // For normal flow blocks (including IFCs): position at full width (cross_start = 0)
        // For BFC-establishing blocks: position in available space between floats
        let (child_cross_pos, mut child_main_pos) = if establishes_bfc {
            // BFC: Position in space between floats
            (
                cross_start + child_margin.cross_start(writing_mode),
                main_pen,
            )
        } else {
            // Normal flow: Position at full width (floats don't affect box position)
            (child_margin.cross_start(writing_mode), main_pen)
        };

        // CSS 2.2 § 8.3.1: If child's top margin escaped through parent, adjust position
        // "If the top margin of a box collapses with its first child's top margin,
        // the top border edge of the box is defined to coincide with the top border edge of the
        // child." This means the child's margin appears ABOVE the parent, so we offset the
        // child down. IMPORTANT: This only applies to the FIRST child! For siblings, normal
        // margin collapse applies.
        let child_escaped_margin = child_node.escaped_top_margin.unwrap_or(0.0);
        let is_first_in_flow_child = Some(child_index) == first_child_index;

        if child_escaped_margin > 0.0 && is_first_in_flow_child {
            child_main_pos += child_escaped_margin;
            total_escaped_top_margin += child_escaped_margin;
            debug_info!(
                ctx,
                "[layout_bfc] FIRST child {} has escaped_top_margin={}, adjusting position from \
                 {} to {}, total_escaped={}",
                child_index,
                child_escaped_margin,
                main_pen,
                child_main_pos,
                total_escaped_top_margin
            );
        } else if child_escaped_margin > 0.0 {
            debug_info!(
                ctx,
                "[layout_bfc] NON-FIRST child {} has escaped_top_margin={} but NOT adjusting \
                 position (sibling margin collapse handles this)",
                child_index,
                child_escaped_margin
            );
        }

        let final_pos =
            LogicalPosition::from_main_cross(child_main_pos, child_cross_pos, writing_mode);

        debug_info!(
            ctx,
            "[layout_bfc] *** NORMAL FLOW BLOCK POSITIONED: child={}, final_pos={:?}, \
             main_pen={}, establishes_bfc={}",
            child_index,
            final_pos,
            main_pen,
            establishes_bfc
        );

        // Re-layout IFC children with float context for correct text wrapping
        // Normal flow blocks WITH inline content need float context propagated
        if is_inline_fc && !establishes_bfc {
            // Use cached floats if available (from previous layout passes),
            // otherwise use the floats positioned in this pass
            let floats_for_ifc = float_cache.get(&node_index).unwrap_or(&float_context);

            debug_info!(
                ctx,
                "[layout_bfc] Re-layouting IFC child {} (normal flow) with parent's float context \
                 at Y={}, child_cross_pos={}",
                child_index,
                main_pen,
                child_cross_pos
            );
            debug_info!(
                ctx,
                "[layout_bfc]   Using {} floats (from cache: {})",
                floats_for_ifc.floats.len(),
                float_cache.contains_key(&node_index)
            );

            // Translate float coordinates from BFC-relative to IFC-relative
            // The IFC child is positioned at (child_cross_pos, main_pen) in BFC coordinates
            // Floats need to be relative to the IFC's CONTENT-BOX origin (inside padding/border)
            let child_node = tree.get(child_index).ok_or(LayoutError::InvalidTree)?;
            let padding_border_cross = child_node.box_props.padding.cross_start(writing_mode)
                + child_node.box_props.border.cross_start(writing_mode);
            let padding_border_main = child_node.box_props.padding.main_start(writing_mode)
                + child_node.box_props.border.main_start(writing_mode);

            // Content-box origin in BFC coordinates
            let content_box_cross = child_cross_pos + padding_border_cross;
            let content_box_main = main_pen + padding_border_main;

            debug_info!(
                ctx,
                "[layout_bfc]   Border-box at ({}, {}), Content-box at ({}, {}), \
                 padding+border=({}, {})",
                child_cross_pos,
                main_pen,
                content_box_cross,
                content_box_main,
                padding_border_cross,
                padding_border_main
            );

            let mut ifc_floats = FloatingContext::default();
            for float_box in &floats_for_ifc.floats {
                // Convert float position from BFC coords to IFC CONTENT-BOX relative coords
                let float_rel_to_ifc = LogicalRect {
                    origin: LogicalPosition {
                        x: float_box.rect.origin.x - content_box_cross,
                        y: float_box.rect.origin.y - content_box_main,
                    },
                    size: float_box.rect.size,
                };

                debug_info!(
                    ctx,
                    "[layout_bfc] Float {:?}: BFC coords = {:?}, IFC-content-relative = {:?}",
                    float_box.kind,
                    float_box.rect,
                    float_rel_to_ifc
                );

                ifc_floats.add_float(float_box.kind, float_rel_to_ifc, float_box.margin);
            }

            // Create a BfcState with IFC-relative float coordinates
            let mut bfc_state = BfcState {
                pen: LogicalPosition::zero(), // IFC starts at its own origin
                floats: ifc_floats.clone(),
                margins: MarginCollapseContext::default(),
            };

            debug_info!(
                ctx,
                "[layout_bfc]   Created IFC-relative FloatingContext with {} floats",
                ifc_floats.floats.len()
            );

            // Get the IFC child's content-box size (after padding/border)
            let child_node = tree.get(child_index).ok_or(LayoutError::InvalidTree)?;
            let child_dom_id = child_node.dom_node_id;

            // For inline elements (display: inline), use containing block width as available
            // width. Inline elements flow within the containing block and wrap at its width.
            // CSS 2.2 § 10.3.1: For inline elements, available width = containing block width.
            let display = get_display_property(ctx.styled_dom, child_dom_id).unwrap_or_default();
            let child_content_size = if display == LayoutDisplay::Inline {
                // Inline elements use the containing block's content-box width
                LogicalSize::new(
                    children_containing_block_size.width,
                    children_containing_block_size.height,
                )
            } else {
                // Block-level elements use their own content-box
                child_node.box_props.inner_size(child_size, writing_mode)
            };

            debug_info!(
                ctx,
                "[layout_bfc]   IFC child size: border-box={:?}, content-box={:?}",
                child_size,
                child_content_size
            );

            // Create new constraints with float context
            // IMPORTANT: Use the child's CONTENT-BOX width, not the BFC width!
            let ifc_constraints = LayoutConstraints {
                available_size: child_content_size,
                bfc_state: Some(&mut bfc_state),
                writing_mode,
                text_align: constraints.text_align,
                containing_block_size: constraints.containing_block_size,
                available_width_type: Text3AvailableSpace::Definite(child_content_size.width),
            };

            // Re-layout the IFC with float awareness
            // This will pass floats as exclusion zones to text3 for line wrapping
            let ifc_result = layout_formatting_context(
                ctx,
                tree,
                text_cache,
                child_index,
                &ifc_constraints,
                float_cache,
            )?;

            // DON'T update used_size - the box keeps its full width!
            // Only the text layout inside changes to wrap around floats

            debug_info!(
                ctx,
                "[layout_bfc] IFC child {} re-layouted with float context (text will wrap, box \
                 stays full width)",
                child_index
            );

            // Merge positions from IFC output (inline-block children, etc.)
            for (idx, pos) in ifc_result.output.positions {
                output.positions.insert(idx, pos);
            }
        }

        output.positions.insert(child_index, final_pos);

        // Advance the pen past the child's content size
        // For FIRST child with escaped margin: the escaped margin was added to position,
        // so we need to add it to main_pen too for correct sibling positioning
        // For NON-FIRST children: escaped margins are internal to that child, don't affect our pen
        if is_first_in_flow_child && child_escaped_margin > 0.0 {
            main_pen += child_size.main(writing_mode) + child_escaped_margin;
            debug_info!(
                ctx,
                "[layout_bfc] Advanced main_pen by child_size={} + escaped={} = {} total",
                child_size.main(writing_mode),
                child_escaped_margin,
                main_pen
            );
        } else {
            main_pen += child_size.main(writing_mode);
        }
        has_content = true;

        // Update last margin for next sibling
        // CSS 2.2 § 8.3.1: The bottom margin of this box will collapse with the top margin
        // of the next sibling (if no clearance or blockers intervene)
        // CSS 2.2 § 9.5.2: If clearance was applied, margin collapsing is inhibited
        if clearance_applied {
            // Clearance inhibits collapse - next sibling starts fresh
            last_margin_bottom = 0.0;
        } else {
            last_margin_bottom = child_margin_bottom;
        }

        debug_info!(
            ctx,
            "[layout_bfc] Child {} positioned at final_pos={:?}, size={:?}, advanced main_pen to \
             {}, last_margin_bottom={}, clearance_applied={}",
            child_index,
            final_pos,
            child_size,
            main_pen,
            last_margin_bottom,
            clearance_applied
        );

        // Track the maximum cross-axis size to determine the BFC's overflow size.
        let child_cross_extent =
            child_cross_pos + child_size.cross(writing_mode) + child_margin.cross_end(writing_mode);
        max_cross_size = max_cross_size.max(child_cross_extent);
    }

    // Store the float context in cache for future layout passes
    // This happens after ALL children (floats and normal) have been positioned
    debug_info!(
        ctx,
        "[layout_bfc] Storing {} floats in cache for node {}",
        float_context.floats.len(),
        node_index
    );
    float_cache.insert(node_index, float_context.clone());

    // PHASE 3: Parent-Child Bottom Margin Escape
    let mut escaped_top_margin = None;
    let mut escaped_bottom_margin = None;

    // Handle top margin escape
    if top_margin_escaped {
        // First child's margin escaped through parent
        escaped_top_margin = Some(accumulated_top_margin);
        debug_info!(
            ctx,
            "[layout_bfc] Returning escaped top margin: accumulated={}, node={}",
            accumulated_top_margin,
            node_index
        );
    } else if !top_margin_resolved && accumulated_top_margin > 0.0 {
        // No content was positioned, all margins accumulated (empty blocks)
        escaped_top_margin = Some(accumulated_top_margin);
        debug_info!(
            ctx,
            "[layout_bfc] Escaping top margin (no content): accumulated={}, node={}",
            accumulated_top_margin,
            node_index
        );
    } else if !top_margin_resolved {
        // Unusual case: no content, zero margin
        escaped_top_margin = Some(accumulated_top_margin);
        debug_info!(
            ctx,
            "[layout_bfc] Escaping top margin (zero, no content): accumulated={}, node={}",
            accumulated_top_margin,
            node_index
        );
    } else {
        debug_info!(
            ctx,
            "[layout_bfc] NOT escaping top margin: top_margin_resolved={}, escaped={}, \
             accumulated={}, node={}",
            top_margin_resolved,
            top_margin_escaped,
            accumulated_top_margin,
            node_index
        );
    }

    // Handle bottom margin escape
    if let Some(last_idx) = last_child_index {
        let last_child = tree.get(last_idx).ok_or(LayoutError::InvalidTree)?;
        let last_has_bottom_blocker =
            has_margin_collapse_blocker(&last_child.box_props, writing_mode, false);

        debug_info!(
            ctx,
            "[layout_bfc] Bottom margin for node {}: parent_has_bottom_blocker={}, \
             last_has_bottom_blocker={}, last_margin_bottom={}, main_pen_before={}",
            node_index,
            parent_has_bottom_blocker,
            last_has_bottom_blocker,
            last_margin_bottom,
            main_pen
        );

        if !parent_has_bottom_blocker && !last_has_bottom_blocker && has_content {
            // Last child's bottom margin can escape
            let collapsed_bottom = collapse_margins(parent_margin_bottom, last_margin_bottom);
            escaped_bottom_margin = Some(collapsed_bottom);
            debug_info!(
                ctx,
                "[layout_bfc] Bottom margin ESCAPED for node {}: collapsed={}",
                node_index,
                collapsed_bottom
            );
            // Don't add last_margin_bottom to pen (it escaped)
        } else {
            // Can't escape: add to pen
            main_pen += last_margin_bottom;
            // NOTE: We do NOT add parent_margin_bottom to main_pen here!
            // parent_margin_bottom is added OUTSIDE the content-box (in the margin-box)
            // The content-box height should only include children's content and margins
            debug_info!(
                ctx,
                "[layout_bfc] Bottom margin BLOCKED for node {}: added last_margin_bottom={}, \
                 main_pen_after={}",
                node_index,
                last_margin_bottom,
                main_pen
            );
        }
    } else {
        // No children: just use parent's margins
        if !top_margin_resolved {
            main_pen += parent_margin_top;
        }
        main_pen += parent_margin_bottom;
    }

    // CRITICAL: If this is a root node (no parent), apply escaped margins directly
    // instead of propagating them upward (since there's no parent to receive them)
    let is_root_node = node.parent.is_none();
    if is_root_node {
        if let Some(top) = escaped_top_margin {
            // Adjust all child positions downward by the escaped top margin
            for (_, pos) in output.positions.iter_mut() {
                let current_main = pos.main(writing_mode);
                *pos = LogicalPosition::from_main_cross(
                    current_main + top,
                    pos.cross(writing_mode),
                    writing_mode,
                );
            }
            main_pen += top;
        }
        if let Some(bottom) = escaped_bottom_margin {
            main_pen += bottom;
        }
        // For root nodes, don't propagate margins further
        escaped_top_margin = None;
        escaped_bottom_margin = None;
    }

    // CSS 2.2 § 9.5: Floats don't contribute to container height with overflow:visible
    //
    // However, browsers DO expand containers to contain floats in specific cases:
    //
    // 1. If there's NO in-flow content (main_pen == 0), floats determine height
    // 2. If container establishes a BFC (overflow != visible)
    //
    // In this case, we have in-flow content (main_pen > 0) and overflow:visible,
    // so floats should NOT expand the container. Their margins can "bleed" beyond
    // the container boundaries into the parent.
    //
    // This matches Chrome/Firefox behavior where float margins escape through
    // the container's padding when there's existing in-flow content.

    // Content-box Height Calculation
    //
    // CSS 2.2 § 8.3.1: "The top border edge of the box is defined to coincide with
    // the top border edge of the [first] child" when margins collapse/escape.
    //
    // This means escaped margins do NOT contribute to the parent's content-box height.
    //
    // Calculation:
    //
    //   main_pen = total vertical space used by all children and margins
    //
    //   Components of main_pen:
    //
    //   1. Children's border-boxes (always included)
    //   2. Sibling collapsed margins (space BETWEEN children - part of content)
    //   3. First child's position (0 if margin escaped, margin_top if blocked)
    //
    //   What to subtract:
    //
    //   - total_escaped_top_margin: First child's margin that went to grandparent's space This
    //     margin is OUTSIDE our content-box, so we must subtract it.
    //
    //   What NOT to subtract:
    //
    //   - total_sibling_margins: These are the gaps BETWEEN children, which are
    //    legitimately part of our content area's layout space.
    //
    // Example with escaped margin:
    //   <div class="parent" padding=0>              <!-- Node 2 -->
    //     <div class="child1" margin=30></div>      <!-- Node 3, margin escapes -->
    //     <div class="child2" margin=40></div>      <!-- Node 5 -->
    //   </div>
    //
    //   Layout process:
    //
    //   - Node 3 positioned at main_pen=0 (margin escaped)
    //   - Node 3 size=140px → main_pen advances to 140
    //   - Sibling collapse: max(30 child1 bottom, 40 child2 top) = 40px
    //   - main_pen advances to 180
    //   - Node 5 size=130px → main_pen advances to 310
    //   - total_escaped_top_margin = 30
    //   - total_sibling_margins = 40 (tracked but NOT subtracted)
    //   - content_box_height = 310 - 30 = 280px ✓
    //
    // Previously, we calculated:
    //
    //   content_box_height = main_pen - total_escaped_top_margin - total_sibling_margins
    //
    // This incorrectly subtracted sibling margins, making parent too small.
    // Sibling margins are *between* boxes (part of layout), not *outside* boxes
    // (like escaped margins).

    let content_box_height = main_pen - total_escaped_top_margin;
    output.overflow_size =
        LogicalSize::from_main_cross(content_box_height, max_cross_size, writing_mode);

    debug_info!(
        ctx,
        "[layout_bfc] FINAL for node {}: main_pen={}, total_escaped_top={}, \
         total_sibling_margins={}, content_box_height={}",
        node_index,
        main_pen,
        total_escaped_top_margin,
        total_sibling_margins,
        content_box_height
    );

    // Baseline calculation would happen here in a full implementation.
    output.baseline = None;

    // Store escaped margins in the LayoutNode for use by parent
    if let Some(node_mut) = tree.get_mut(node_index) {
        node_mut.escaped_top_margin = escaped_top_margin;
        node_mut.escaped_bottom_margin = escaped_bottom_margin;
    }

    if let Some(node_mut) = tree.get_mut(node_index) {
        node_mut.baseline = output.baseline;
    }

    Ok(BfcLayoutResult {
        output,
        escaped_top_margin,
        escaped_bottom_margin,
    })
}

// Inline Formatting Context (CSS 2.2 § 9.4.2)

/// Lays out an Inline Formatting Context (IFC) by delegating to the `text3` engine.
///
/// This function acts as a bridge between the box-tree world of `solver3` and the
/// rich text layout world of `text3`. Its responsibilities are:
///
/// 1. **Collect Content**: Traverse the direct children of the IFC root and convert them into a
///    `Vec<InlineContent>`, the input format for `text3`. This involves:
///
///     - Recursively laying out `inline-block` children to determine their final size and baseline,
///       which are then passed to `text3` as opaque objects.
///     - Extracting raw text runs from inline text nodes.
///
/// 2. **Translate Constraints**: Convert the `LayoutConstraints` (available space, floats) from
///    `solver3` into the more detailed `UnifiedConstraints` that `text3` requires.
///
/// 3. **Invoke Text Layout**: Call the `text3` cache's `layout_flow` method to perform the complex
///    tasks of BIDI analysis, shaping, line breaking, justification, and vertical alignment.
///
/// 4. **Integrate Results**: Process the `UnifiedLayout` returned by `text3`:
///
///     - Store the rich layout result on the IFC root `LayoutNode` for the display list generation
///       pass.
///     - Update the `positions` map for all `inline-block` children based on the positions
///       calculated by `text3`.
///     - Extract the final overflow size and baseline for the IFC root itself
fn layout_ifc<T: ParsedFontTrait>(
    ctx: &mut LayoutContext<'_, T>,
    text_cache: &mut crate::font_traits::TextLayoutCache,
    tree: &mut LayoutTree,
    node_index: usize,
    constraints: &LayoutConstraints,
) -> Result<LayoutOutput> {
    let node = tree.get(node_index).ok_or(LayoutError::InvalidTree)?;
    let float_count = constraints
        .bfc_state
        .as_ref()
        .map(|s| s.floats.floats.len())
        .unwrap_or(0);
    debug_info!(
        ctx,
        "[layout_ifc] ENTRY: node_index={}, has_bfc_state={}, float_count={}",
        node_index,
        constraints.bfc_state.is_some(),
        float_count
    );
    debug_ifc_layout!(ctx, "CALLED for node_index={}", node_index);

    // For anonymous boxes, we need to find the DOM ID from a parent or child
    // CSS 2.2 § 9.2.1.1: Anonymous boxes inherit properties from their enclosing box
    let node = tree.get(node_index).ok_or(LayoutError::InvalidTree)?;
    let ifc_root_dom_id = match node.dom_node_id {
        Some(id) => id,
        None => {
            // Anonymous box - get DOM ID from parent or first child with DOM ID
            let parent_dom_id = node
                .parent
                .and_then(|p| tree.get(p))
                .and_then(|n| n.dom_node_id);

            if let Some(id) = parent_dom_id {
                id
            } else {
                // Try to find DOM ID from first child
                node.children
                    .iter()
                    .filter_map(|&child_idx| tree.get(child_idx))
                    .filter_map(|n| n.dom_node_id)
                    .next()
                    .ok_or(LayoutError::InvalidTree)?
            }
        }
    };

    debug_ifc_layout!(ctx, "ifc_root_dom_id={:?}", ifc_root_dom_id);

    // Phase 1: Collect and measure all inline-level children.
    let (inline_content, child_map) =
        collect_and_measure_inline_content(ctx, text_cache, tree, node_index, constraints)?;

    debug_info!(
        ctx,
        "[layout_ifc] Collected {} inline content items for node {}",
        inline_content.len(),
        node_index
    );
    for (i, item) in inline_content.iter().enumerate() {
        match item {
            InlineContent::Text(run) => debug_info!(ctx, "  [{}] Text: '{}'", i, run.text),
            InlineContent::Marker {
                run,
                position_outside,
            } => debug_info!(
                ctx,
                "  [{}] Marker: '{}' (outside={})",
                i,
                run.text,
                position_outside
            ),
            InlineContent::Shape(_) => debug_info!(ctx, "  [{}] Shape", i),
            InlineContent::Image(_) => debug_info!(ctx, "  [{}] Image", i),
            _ => debug_info!(ctx, "  [{}] Other", i),
        }
    }

    debug_ifc_layout!(
        ctx,
        "Collected {} inline content items",
        inline_content.len()
    );

    if inline_content.is_empty() {
        debug_warning!(ctx, "inline_content is empty, returning default output!");
        return Ok(LayoutOutput::default());
    }

    // Phase 2: Translate constraints and define a single layout fragment for text3.
    let text3_constraints =
        translate_to_text3_constraints(ctx, constraints, ctx.styled_dom, ifc_root_dom_id);

    // Clone constraints for caching (before they're moved into fragments)
    let cached_constraints = text3_constraints.clone();

    debug_info!(
        ctx,
        "[layout_ifc] CALLING text_cache.layout_flow for node {} with {} exclusions",
        node_index,
        text3_constraints.shape_exclusions.len()
    );

    let fragments = vec![LayoutFragment {
        id: "main".to_string(),
        constraints: text3_constraints,
    }];

    // Phase 3: Invoke the text layout engine.
    // Get pre-loaded fonts from font manager (fonts should be loaded before layout)
    let loaded_fonts = ctx.font_manager.get_loaded_fonts();
    let text_layout_result = match text_cache.layout_flow(
        &inline_content,
        &[],
        &fragments,
        &ctx.font_manager.font_chain_cache,
        &ctx.font_manager.fc_cache,
        &loaded_fonts,
        ctx.debug_messages,
    ) {
        Ok(result) => result,
        Err(e) => {
            // Font errors should not stop layout of other elements.
            // Log the error and return a zero-sized layout.
            debug_warning!(ctx, "Text layout failed: {:?}", e);
            debug_warning!(
                ctx,
                "Continuing with zero-sized layout for node {}",
                node_index
            );

            let mut output = LayoutOutput::default();
            output.overflow_size = LogicalSize::new(0.0, 0.0);
            return Ok(output);
        }
    };

    // Phase 4: Integrate results back into the solver3 layout tree.
    let mut output = LayoutOutput::default();
    let node = tree.get_mut(node_index).ok_or(LayoutError::InvalidTree)?;

    debug_ifc_layout!(
        ctx,
        "text_layout_result has {} fragment_layouts",
        text_layout_result.fragment_layouts.len()
    );

    if let Some(main_frag) = text_layout_result.fragment_layouts.get("main") {
        let frag_bounds = main_frag.bounds();
        debug_ifc_layout!(
            ctx,
            "Found 'main' fragment with {} items, bounds={}x{}",
            main_frag.items.len(),
            frag_bounds.width,
            frag_bounds.height
        );
        debug_ifc_layout!(ctx, "Storing inline_layout_result on node {}", node_index);

        // Determine if we should store this layout result using the new
        // CachedInlineLayout system. The key insight is that inline layouts
        // depend on available width:
        //
        // - Min-content measurement uses width ≈ 0 (maximum line wrapping)
        // - Max-content measurement uses width = ∞ (no line wrapping)
        // - Final layout uses the actual column/container width
        //
        // We must track which constraint type was used, otherwise a min-content
        // measurement would incorrectly be reused for final rendering.
        let has_floats = constraints
            .bfc_state
            .as_ref()
            .map(|s| !s.floats.floats.is_empty())
            .unwrap_or(false);
        let current_width_type = constraints.available_width_type;

        let should_store = match &node.inline_layout_result {
            None => {
                // No cached result - always store
                debug_info!(
                    ctx,
                    "[layout_ifc] Storing NEW inline_layout_result for node {} (width_type={:?}, \
                     has_floats={})",
                    node_index,
                    current_width_type,
                    has_floats
                );
                true
            }
            Some(cached) => {
                // Check if the new result should replace the cached one
                if cached.should_replace_with(current_width_type, has_floats) {
                    debug_info!(
                        ctx,
                        "[layout_ifc] REPLACING inline_layout_result for node {} (old: \
                         width={:?}, floats={}) with (new: width={:?}, floats={})",
                        node_index,
                        cached.available_width,
                        cached.has_floats,
                        current_width_type,
                        has_floats
                    );
                    true
                } else {
                    debug_info!(
                        ctx,
                        "[layout_ifc] KEEPING cached inline_layout_result for node {} (cached: \
                         width={:?}, floats={}, new: width={:?}, floats={})",
                        node_index,
                        cached.available_width,
                        cached.has_floats,
                        current_width_type,
                        has_floats
                    );
                    false
                }
            }
        };

        if should_store {
            node.inline_layout_result = Some(CachedInlineLayout::new_with_constraints(
                main_frag.clone(),
                current_width_type,
                has_floats,
                cached_constraints,
            ));
        }

        // Extract the overall size and baseline for the IFC root.
        output.overflow_size = LogicalSize::new(frag_bounds.width, frag_bounds.height);
        output.baseline = main_frag.last_baseline();
        node.baseline = output.baseline;

        // Position all the inline-block children based on text3's calculations.
        for positioned_item in &main_frag.items {
            if let ShapedItem::Object { source, content, .. } = &positioned_item.item {
                if let Some(&child_node_index) = child_map.get(source) {
                    let new_relative_pos = LogicalPosition {
                        x: positioned_item.position.x,
                        y: positioned_item.position.y,
                    };
                    output.positions.insert(child_node_index, new_relative_pos);
                }
            }
        }
    }

    Ok(output)
}

fn translate_taffy_size(size: LogicalSize) -> TaffySize<Option<f32>> {
    TaffySize {
        width: Some(size.width),
        height: Some(size.height),
    }
}

/// Helper: Convert StyleFontStyle to text3::cache::FontStyle
pub(crate) fn convert_font_style(style: StyleFontStyle) -> crate::font_traits::FontStyle {
    match style {
        StyleFontStyle::Normal => crate::font_traits::FontStyle::Normal,
        StyleFontStyle::Italic => crate::font_traits::FontStyle::Italic,
        StyleFontStyle::Oblique => crate::font_traits::FontStyle::Oblique,
    }
}

/// Helper: Convert StyleFontWeight to FcWeight
pub(crate) fn convert_font_weight(weight: StyleFontWeight) -> FcWeight {
    match weight {
        StyleFontWeight::W100 => FcWeight::Thin,
        StyleFontWeight::W200 => FcWeight::ExtraLight,
        StyleFontWeight::W300 | StyleFontWeight::Lighter => FcWeight::Light,
        StyleFontWeight::Normal => FcWeight::Normal,
        StyleFontWeight::W500 => FcWeight::Medium,
        StyleFontWeight::W600 => FcWeight::SemiBold,
        StyleFontWeight::Bold => FcWeight::Bold,
        StyleFontWeight::W800 => FcWeight::ExtraBold,
        StyleFontWeight::W900 | StyleFontWeight::Bolder => FcWeight::Black,
    }
}

/// Resolves a CSS size metric to pixels.
#[inline]
fn resolve_size_metric(metric: SizeMetric, value: f32, containing_block_size: f32) -> f32 {
    match metric {
        SizeMetric::Px => value,
        SizeMetric::Pt => value * PT_TO_PX,
        SizeMetric::Percent => value / 100.0 * containing_block_size,
        SizeMetric::Em | SizeMetric::Rem => value * DEFAULT_FONT_SIZE,
        _ => value, // Fallback
    }
}

pub fn translate_taffy_size_back(size: TaffySize<f32>) -> LogicalSize {
    LogicalSize {
        width: size.width,
        height: size.height,
    }
}

pub fn translate_taffy_point_back(point: taffy::Point<f32>) -> LogicalPosition {
    LogicalPosition {
        x: point.x,
        y: point.y,
    }
}

/// Checks if a node establishes a new Block Formatting Context (BFC).
///
/// Per CSS 2.2 § 9.4.1, a BFC is established by:
/// - Floats (elements with float other than 'none')
/// - Absolutely positioned elements (position: absolute or fixed)
/// - Block containers that are not block boxes (e.g., inline-blocks, table-cells)
/// - Block boxes with 'overflow' other than 'visible' and 'clip'
/// - Elements with 'display: flow-root'
/// - Table cells, table captions, and inline-blocks
///
/// Normal flow block-level boxes do NOT establish a new BFC.
///
/// This is critical for correct float interaction: normal blocks should overlap floats
/// (not shrink around them), while their inline content wraps around floats.
fn establishes_new_bfc<T: ParsedFontTrait>(ctx: &LayoutContext<'_, T>, node: &LayoutNode) -> bool {
    let Some(dom_id) = node.dom_node_id else {
        return false;
    };

    let node_state = &ctx.styled_dom.styled_nodes.as_container()[dom_id].styled_node_state;

    // 1. Floats establish BFC
    let float_val = get_float(ctx.styled_dom, dom_id, node_state);
    if matches!(
        float_val,
        MultiValue::Exact(LayoutFloat::Left | LayoutFloat::Right)
    ) {
        return true;
    }

    // 2. Absolutely positioned elements establish BFC
    let position = crate::solver3::positioning::get_position_type(ctx.styled_dom, Some(dom_id));
    if matches!(position, LayoutPosition::Absolute | LayoutPosition::Fixed) {
        return true;
    }

    // 3. Inline-blocks, table-cells, table-captions establish BFC
    let display = get_display_property(ctx.styled_dom, Some(dom_id));
    if matches!(
        display,
        MultiValue::Exact(
            LayoutDisplay::InlineBlock | LayoutDisplay::TableCell | LayoutDisplay::TableCaption
        )
    ) {
        return true;
    }

    // 4. display: flow-root establishes BFC
    if matches!(display, MultiValue::Exact(LayoutDisplay::FlowRoot)) {
        return true;
    }

    // 5. Block boxes with overflow other than 'visible' or 'clip' establish BFC
    // Note: 'clip' does NOT establish BFC per CSS Overflow Module Level 3
    let overflow_x = get_overflow_x(ctx.styled_dom, dom_id, node_state);
    let overflow_y = get_overflow_y(ctx.styled_dom, dom_id, node_state);

    let creates_bfc_via_overflow = |ov: &MultiValue<LayoutOverflow>| {
        matches!(
            ov,
            &MultiValue::Exact(
                LayoutOverflow::Hidden | LayoutOverflow::Scroll | LayoutOverflow::Auto
            )
        )
    };

    if creates_bfc_via_overflow(&overflow_x) || creates_bfc_via_overflow(&overflow_y) {
        return true;
    }

    // 6. Table, Flex, and Grid containers establish BFC (via FormattingContext)
    if matches!(
        node.formatting_context,
        FormattingContext::Table | FormattingContext::Flex | FormattingContext::Grid
    ) {
        return true;
    }

    // Normal flow block boxes do NOT establish BFC
    false
}

/// Translates solver3 layout constraints into the text3 engine's unified constraints.
fn translate_to_text3_constraints<'a, T: ParsedFontTrait>(
    ctx: &mut LayoutContext<'_, T>,
    constraints: &'a LayoutConstraints<'a>,
    styled_dom: &StyledDom,
    dom_id: NodeId,
) -> UnifiedConstraints {
    // Convert floats into exclusion zones for text3 to flow around.
    let mut shape_exclusions = if let Some(ref bfc_state) = constraints.bfc_state {
        debug_info!(
            ctx,
            "[translate_to_text3] dom_id={:?}, converting {} floats to exclusions",
            dom_id,
            bfc_state.floats.floats.len()
        );
        bfc_state
            .floats
            .floats
            .iter()
            .enumerate()
            .map(|(i, float_box)| {
                let rect = crate::text3::cache::Rect {
                    x: float_box.rect.origin.x,
                    y: float_box.rect.origin.y,
                    width: float_box.rect.size.width,
                    height: float_box.rect.size.height,
                };
                debug_info!(
                    ctx,
                    "[translate_to_text3]   Exclusion #{}: {:?} at ({}, {}) size {}x{}",
                    i,
                    float_box.kind,
                    rect.x,
                    rect.y,
                    rect.width,
                    rect.height
                );
                ShapeBoundary::Rectangle(rect)
            })
            .collect()
    } else {
        debug_info!(
            ctx,
            "[translate_to_text3] dom_id={:?}, NO bfc_state - no float exclusions",
            dom_id
        );
        Vec::new()
    };

    debug_info!(
        ctx,
        "[translate_to_text3] dom_id={:?}, available_size={}x{}, shape_exclusions.len()={}",
        dom_id,
        constraints.available_size.width,
        constraints.available_size.height,
        shape_exclusions.len()
    );

    // Map text-align and justify-content from CSS to text3 enums.
    let id = dom_id;
    let node_data = &styled_dom.node_data.as_container()[id];
    let node_state = &styled_dom.styled_nodes.as_container()[id].styled_node_state;

    // Read CSS Shapes properties
    // For reference box, use the element's CSS height if available, otherwise available_size
    // This is important because available_size.height might be infinite during auto height
    // calculation
    let ref_box_height = if constraints.available_size.height.is_finite() {
        constraints.available_size.height
    } else {
        // Try to get explicit CSS height
        // NOTE: If height is infinite, we can't properly resolve % heights
        // This is a limitation - shape-inside with % heights requires finite containing block
        styled_dom
            .css_property_cache
            .ptr
            .get_height(node_data, &id, node_state)
            .and_then(|v| v.get_property())
            .and_then(|h| match h {
                LayoutHeight::Px(v) => {
                    // Only accept absolute units (px, pt, in, cm, mm) - no %, em, rem
                    // since we can't resolve relative units without proper context
                    match v.metric {
                        SizeMetric::Px => Some(v.number.get()),
                        SizeMetric::Pt => Some(v.number.get() * PT_TO_PX),
                        SizeMetric::In => Some(v.number.get() * 96.0),
                        SizeMetric::Cm => Some(v.number.get() * 96.0 / 2.54),
                        SizeMetric::Mm => Some(v.number.get() * 96.0 / 25.4),
                        _ => None, // Ignore %, em, rem
                    }
                }
                _ => None,
            })
            .unwrap_or(constraints.available_size.width) // Fallback: use width as height (square)
    };

    let reference_box = crate::text3::cache::Rect {
        x: 0.0,
        y: 0.0,
        width: constraints.available_size.width,
        height: ref_box_height,
    };

    // shape-inside: Text flows within the shape boundary
    debug_info!(ctx, "Checking shape-inside for node {:?}", id);
    debug_info!(
        ctx,
        "Reference box: {:?} (available_size height was: {})",
        reference_box,
        constraints.available_size.height
    );

    let shape_boundaries = styled_dom
        .css_property_cache
        .ptr
        .get_shape_inside(node_data, &id, node_state)
        .and_then(|v| {
            debug_info!(ctx, "Got shape-inside value: {:?}", v);
            v.get_property()
        })
        .and_then(|shape_inside| {
            debug_info!(ctx, "shape-inside property: {:?}", shape_inside);
            if let ShapeInside::Shape(css_shape) = shape_inside {
                debug_info!(
                    ctx,
                    "Converting CSS shape to ShapeBoundary: {:?}",
                    css_shape
                );
                let boundary =
                    ShapeBoundary::from_css_shape(css_shape, reference_box, ctx.debug_messages);
                debug_info!(ctx, "Created ShapeBoundary: {:?}", boundary);
                Some(vec![boundary])
            } else {
                debug_info!(ctx, "shape-inside is None");
                None
            }
        })
        .unwrap_or_default();

    debug_info!(
        ctx,
        "Final shape_boundaries count: {}",
        shape_boundaries.len()
    );

    // shape-outside: Text wraps around the shape (adds to exclusions)
    debug_info!(ctx, "Checking shape-outside for node {:?}", id);
    if let Some(shape_outside_value) = styled_dom
        .css_property_cache
        .ptr
        .get_shape_outside(node_data, &id, node_state)
    {
        debug_info!(ctx, "Got shape-outside value: {:?}", shape_outside_value);
        if let Some(shape_outside) = shape_outside_value.get_property() {
            debug_info!(ctx, "shape-outside property: {:?}", shape_outside);
            if let ShapeOutside::Shape(css_shape) = shape_outside {
                debug_info!(
                    ctx,
                    "Converting CSS shape-outside to ShapeBoundary: {:?}",
                    css_shape
                );
                let boundary =
                    ShapeBoundary::from_css_shape(css_shape, reference_box, ctx.debug_messages);
                debug_info!(ctx, "Created ShapeBoundary (exclusion): {:?}", boundary);
                shape_exclusions.push(boundary);
            }
        }
    } else {
        debug_info!(ctx, "No shape-outside value found");
    }

    // TODO: clip-path will be used for rendering clipping (not text layout)

    let writing_mode = styled_dom
        .css_property_cache
        .ptr
        .get_writing_mode(node_data, &id, node_state)
        .and_then(|s| s.get_property().copied())
        .unwrap_or_default();

    let text_align = styled_dom
        .css_property_cache
        .ptr
        .get_text_align(node_data, &id, node_state)
        .and_then(|s| s.get_property().copied())
        .unwrap_or_default();

    let text_justify = styled_dom
        .css_property_cache
        .ptr
        .get_text_justify(node_data, &id, node_state)
        .and_then(|s| s.get_property().copied())
        .unwrap_or_default();

    // Get font-size for resolving line-height
    // Use helper function which checks dependency chain first
    let font_size = get_element_font_size(styled_dom, id, node_state);

    let line_height_value = styled_dom
        .css_property_cache
        .ptr
        .get_line_height(node_data, &id, node_state)
        .and_then(|s| s.get_property().cloned())
        .unwrap_or_default();

    let hyphenation = styled_dom
        .css_property_cache
        .ptr
        .get_hyphens(node_data, &id, node_state)
        .and_then(|s| s.get_property().copied())
        .unwrap_or_default();

    let overflow_behaviour = styled_dom
        .css_property_cache
        .ptr
        .get_overflow_x(node_data, &id, node_state)
        .and_then(|s| s.get_property().copied())
        .unwrap_or_default();

    // Get vertical-align from CSS property cache (defaults to Baseline per CSS spec)
    let vertical_align = styled_dom
        .css_property_cache
        .ptr
        .get_vertical_align(node_data, &id, node_state)
        .and_then(|s| s.get_property().copied())
        .unwrap_or_default();

    let vertical_align = match vertical_align {
        StyleVerticalAlign::Baseline => text3::cache::VerticalAlign::Baseline,
        StyleVerticalAlign::Top => text3::cache::VerticalAlign::Top,
        StyleVerticalAlign::Middle => text3::cache::VerticalAlign::Middle,
        StyleVerticalAlign::Bottom => text3::cache::VerticalAlign::Bottom,
        StyleVerticalAlign::Sub => text3::cache::VerticalAlign::Sub,
        StyleVerticalAlign::Superscript => text3::cache::VerticalAlign::Super,
        StyleVerticalAlign::TextTop => text3::cache::VerticalAlign::TextTop,
        StyleVerticalAlign::TextBottom => text3::cache::VerticalAlign::TextBottom,
    };
    let text_orientation = text3::cache::TextOrientation::default();

    // Get the direction property from the CSS cache (defaults to LTR if not set)
    let direction = styled_dom
        .css_property_cache
        .ptr
        .get_direction(node_data, &id, node_state)
        .and_then(|s| s.get_property().copied())
        .map(|d| match d {
            StyleDirection::Ltr => text3::cache::BidiDirection::Ltr,
            StyleDirection::Rtl => text3::cache::BidiDirection::Rtl,
        });

    debug_info!(
        ctx,
        "dom_id={:?}, available_size={}x{}, setting available_width={}",
        dom_id,
        constraints.available_size.width,
        constraints.available_size.height,
        constraints.available_size.width
    );

    // Get text-indent
    let text_indent = styled_dom
        .css_property_cache
        .ptr
        .get_text_indent(node_data, &id, node_state)
        .and_then(|s| s.get_property())
        .map(|ti| {
            let context = ResolutionContext {
                element_font_size: get_element_font_size(styled_dom, id, node_state),
                parent_font_size: get_parent_font_size(styled_dom, id, node_state),
                root_font_size: get_root_font_size(styled_dom, node_state),
                containing_block_size: PhysicalSize::new(constraints.available_size.width, 0.0),
                element_size: None,
                viewport_size: PhysicalSize::new(0.0, 0.0),
            };
            ti.inner
                .resolve_with_context(&context, PropertyContext::Other)
        })
        .unwrap_or(0.0);

    // Get column-count for multi-column layout (default: 1 = no columns)
    let columns = styled_dom
        .css_property_cache
        .ptr
        .get_column_count(node_data, &id, node_state)
        .and_then(|s| s.get_property())
        .map(|cc| match cc {
            ColumnCount::Integer(n) => *n,
            ColumnCount::Auto => 1,
        })
        .unwrap_or(1);

    // Get column-gap for multi-column layout (default: normal = 1em)
    let column_gap = styled_dom
        .css_property_cache
        .ptr
        .get_column_gap(node_data, &id, node_state)
        .and_then(|s| s.get_property())
        .map(|cg| {
            let context = ResolutionContext {
                element_font_size: get_element_font_size(styled_dom, id, node_state),
                parent_font_size: get_parent_font_size(styled_dom, id, node_state),
                root_font_size: get_root_font_size(styled_dom, node_state),
                containing_block_size: PhysicalSize::new(0.0, 0.0),
                element_size: None,
                viewport_size: PhysicalSize::new(0.0, 0.0),
            };
            cg.inner
                .resolve_with_context(&context, PropertyContext::Other)
        })
        .unwrap_or_else(|| {
            // Default: 1em
            get_element_font_size(styled_dom, id, node_state)
        });

    // Map white-space CSS property to TextWrap
    let text_wrap = styled_dom
        .css_property_cache
        .ptr
        .get_white_space(node_data, &id, node_state)
        .and_then(|s| s.get_property())
        .map(|ws| match ws {
            StyleWhiteSpace::Normal => text3::cache::TextWrap::Wrap,
            StyleWhiteSpace::Nowrap => text3::cache::TextWrap::NoWrap,
            StyleWhiteSpace::Pre => text3::cache::TextWrap::NoWrap,
        })
        .unwrap_or(text3::cache::TextWrap::Wrap);

    // Get initial-letter for drop caps
    let initial_letter = styled_dom
        .css_property_cache
        .ptr
        .get_initial_letter(node_data, &id, node_state)
        .and_then(|s| s.get_property())
        .map(|il| {
            use std::num::NonZeroUsize;
            let sink = match il.sink {
                azul_css::corety::OptionU32::Some(s) => s,
                azul_css::corety::OptionU32::None => il.size,
            };
            text3::cache::InitialLetter {
                size: il.size as f32,
                sink,
                count: NonZeroUsize::new(1).unwrap(),
            }
        });

    // Get line-clamp for limiting visible lines
    let line_clamp = styled_dom
        .css_property_cache
        .ptr
        .get_line_clamp(node_data, &id, node_state)
        .and_then(|s| s.get_property())
        .and_then(|lc| std::num::NonZeroUsize::new(lc.max_lines));

    // Get hanging-punctuation for hanging punctuation marks
    let hanging_punctuation = styled_dom
        .css_property_cache
        .ptr
        .get_hanging_punctuation(node_data, &id, node_state)
        .and_then(|s| s.get_property())
        .map(|hp| hp.enabled)
        .unwrap_or(false);

    // Get text-combine-upright for vertical text combination
    let text_combine_upright = styled_dom
        .css_property_cache
        .ptr
        .get_text_combine_upright(node_data, &id, node_state)
        .and_then(|s| s.get_property())
        .map(|tcu| match tcu {
            StyleTextCombineUpright::None => text3::cache::TextCombineUpright::None,
            StyleTextCombineUpright::All => text3::cache::TextCombineUpright::All,
            StyleTextCombineUpright::Digits(n) => text3::cache::TextCombineUpright::Digits(*n),
        });

    // Get exclusion-margin for shape exclusions
    let exclusion_margin = styled_dom
        .css_property_cache
        .ptr
        .get_exclusion_margin(node_data, &id, node_state)
        .and_then(|s| s.get_property())
        .map(|em| em.inner.get() as f32)
        .unwrap_or(0.0);

    // Get hyphenation-language for language-specific hyphenation
    let hyphenation_language = styled_dom
        .css_property_cache
        .ptr
        .get_hyphenation_language(node_data, &id, node_state)
        .and_then(|s| s.get_property())
        .and_then(|hl| {
            #[cfg(feature = "text_layout_hyphenation")]
            {
                use hyphenation::{Language, Load};
                // Parse BCP 47 language code to hyphenation::Language
                match hl.inner.as_str() {
                    "en-US" | "en" => Some(Language::EnglishUS),
                    "de-DE" | "de" => Some(Language::German1996),
                    "fr-FR" | "fr" => Some(Language::French),
                    "es-ES" | "es" => Some(Language::Spanish),
                    "it-IT" | "it" => Some(Language::Italian),
                    "pt-PT" | "pt" => Some(Language::Portuguese),
                    "nl-NL" | "nl" => Some(Language::Dutch),
                    "pl-PL" | "pl" => Some(Language::Polish),
                    "ru-RU" | "ru" => Some(Language::Russian),
                    "zh-CN" | "zh" => Some(Language::Chinese),
                    _ => None, // Unsupported language
                }
            }
            #[cfg(not(feature = "text_layout_hyphenation"))]
            {
                None::<crate::text3::script::Language>
            }
        });

    UnifiedConstraints {
        exclusion_margin,
        hyphenation_language,
        text_indent,
        initial_letter,
        line_clamp,
        columns,
        column_gap,
        hanging_punctuation,
        text_wrap,
        text_combine_upright,
        segment_alignment: SegmentAlignment::Total,
        overflow: match overflow_behaviour {
            LayoutOverflow::Visible => text3::cache::OverflowBehavior::Visible,
            LayoutOverflow::Hidden | LayoutOverflow::Clip => text3::cache::OverflowBehavior::Hidden,
            LayoutOverflow::Scroll => text3::cache::OverflowBehavior::Scroll,
            LayoutOverflow::Auto => text3::cache::OverflowBehavior::Auto,
        },
        available_width: text3::cache::AvailableSpace::from_f32(constraints.available_size.width),
        // For scrollable containers (overflow: scroll/auto), don't constrain height
        // so that the full content is laid out and content_size is calculated correctly.
        available_height: match overflow_behaviour {
            LayoutOverflow::Scroll | LayoutOverflow::Auto => None,
            _ => Some(constraints.available_size.height),
        },
        shape_boundaries, // CSS shape-inside: text flows within shape
        shape_exclusions, // CSS shape-outside + floats: text wraps around shapes
        writing_mode: Some(match writing_mode {
            LayoutWritingMode::HorizontalTb => text3::cache::WritingMode::HorizontalTb,
            LayoutWritingMode::VerticalRl => text3::cache::WritingMode::VerticalRl,
            LayoutWritingMode::VerticalLr => text3::cache::WritingMode::VerticalLr,
        }),
        direction, // Use the CSS direction property (currently defaulting to LTR)
        hyphenation: match hyphenation {
            StyleHyphens::None => false,
            StyleHyphens::Auto => true,
        },
        text_orientation,
        text_align: match text_align {
            StyleTextAlign::Start => text3::cache::TextAlign::Start,
            StyleTextAlign::End => text3::cache::TextAlign::End,
            StyleTextAlign::Left => text3::cache::TextAlign::Left,
            StyleTextAlign::Right => text3::cache::TextAlign::Right,
            StyleTextAlign::Center => text3::cache::TextAlign::Center,
            StyleTextAlign::Justify => text3::cache::TextAlign::Justify,
        },
        text_justify: match text_justify {
            LayoutTextJustify::None => text3::cache::JustifyContent::None,
            LayoutTextJustify::Auto => text3::cache::JustifyContent::None,
            LayoutTextJustify::InterWord => text3::cache::JustifyContent::InterWord,
            LayoutTextJustify::InterCharacter => text3::cache::JustifyContent::InterCharacter,
            LayoutTextJustify::Distribute => text3::cache::JustifyContent::Distribute,
        },
        line_height: line_height_value.inner.normalized() * font_size, /* Resolve line-height relative to font-size */
        vertical_align, // CSS vertical-align property (defaults to Baseline)
    }
}

// Table Formatting Context (CSS 2.2 § 17)

/// Lays out a Table Formatting Context.
/// Table column information for layout calculations
#[derive(Debug, Clone)]
pub struct TableColumnInfo {
    /// Minimum width required for this column
    pub min_width: f32,
    /// Maximum width desired for this column
    pub max_width: f32,
    /// Computed final width for this column
    pub computed_width: Option<f32>,
}

/// Information about a table cell for layout
#[derive(Debug, Clone)]
pub struct TableCellInfo {
    /// Node index in the layout tree
    pub node_index: usize,
    /// Column index (0-based)
    pub column: usize,
    /// Number of columns this cell spans
    pub colspan: usize,
    /// Row index (0-based)
    pub row: usize,
    /// Number of rows this cell spans
    pub rowspan: usize,
}

/// Table layout context - holds all information needed for table layout
#[derive(Debug)]
struct TableLayoutContext {
    /// Information about each column
    columns: Vec<TableColumnInfo>,
    /// Information about each cell
    cells: Vec<TableCellInfo>,
    /// Number of rows in the table
    num_rows: usize,
    /// Whether to use fixed or auto layout algorithm
    use_fixed_layout: bool,
    /// Computed height for each row
    row_heights: Vec<f32>,
    /// Border collapse mode
    border_collapse: StyleBorderCollapse,
    /// Border spacing (only used when border_collapse is Separate)
    border_spacing: LayoutBorderSpacing,
    /// CSS 2.2 Section 17.4: Index of table-caption child, if any
    caption_index: Option<usize>,
    /// CSS 2.2 Section 17.6: Rows with visibility:collapse (dynamic effects)
    /// Set of row indices that have visibility:collapse
    collapsed_rows: std::collections::HashSet<usize>,
    /// CSS 2.2 Section 17.6: Columns with visibility:collapse (dynamic effects)
    /// Set of column indices that have visibility:collapse
    collapsed_columns: std::collections::HashSet<usize>,
}

impl TableLayoutContext {
    fn new() -> Self {
        Self {
            columns: Vec::new(),
            cells: Vec::new(),
            num_rows: 0,
            use_fixed_layout: false,
            row_heights: Vec::new(),
            border_collapse: StyleBorderCollapse::Separate,
            border_spacing: LayoutBorderSpacing::default(),
            caption_index: None,
            collapsed_rows: std::collections::HashSet::new(),
            collapsed_columns: std::collections::HashSet::new(),
        }
    }
}

/// Source of a border in the border conflict resolution algorithm
#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord)]
pub enum BorderSource {
    Table = 0,
    ColumnGroup = 1,
    Column = 2,
    RowGroup = 3,
    Row = 4,
    Cell = 5,
}

/// Information about a border for conflict resolution
#[derive(Debug, Clone)]
pub struct BorderInfo {
    pub width: f32,
    pub style: BorderStyle,
    pub color: ColorU,
    pub source: BorderSource,
}

impl BorderInfo {
    pub fn new(width: f32, style: BorderStyle, color: ColorU, source: BorderSource) -> Self {
        Self {
            width,
            style,
            color,
            source,
        }
    }

    /// Get the priority of a border style for conflict resolution
    /// Higher number = higher priority
    pub fn style_priority(style: &BorderStyle) -> u8 {
        match style {
            BorderStyle::Hidden => 255, // Highest - suppresses all borders
            BorderStyle::None => 0,     // Lowest - loses to everything
            BorderStyle::Double => 8,
            BorderStyle::Solid => 7,
            BorderStyle::Dashed => 6,
            BorderStyle::Dotted => 5,
            BorderStyle::Ridge => 4,
            BorderStyle::Outset => 3,
            BorderStyle::Groove => 2,
            BorderStyle::Inset => 1,
        }
    }

    /// Compare two borders for conflict resolution per CSS 2.2 Section 17.6.2.1
    /// Returns the winning border
    pub fn resolve_conflict(a: &BorderInfo, b: &BorderInfo) -> Option<BorderInfo> {
        // 1. 'hidden' wins and suppresses all borders
        if a.style == BorderStyle::Hidden || b.style == BorderStyle::Hidden {
            return None;
        }

        // 2. Filter out 'none' - if both are none, no border
        let a_is_none = a.style == BorderStyle::None;
        let b_is_none = b.style == BorderStyle::None;

        if a_is_none && b_is_none {
            return None;
        }
        if a_is_none {
            return Some(b.clone());
        }
        if b_is_none {
            return Some(a.clone());
        }

        // 3. Wider border wins
        if a.width > b.width {
            return Some(a.clone());
        }
        if b.width > a.width {
            return Some(b.clone());
        }

        // 4. If same width, compare style priority
        let a_priority = Self::style_priority(&a.style);
        let b_priority = Self::style_priority(&b.style);

        if a_priority > b_priority {
            return Some(a.clone());
        }
        if b_priority > a_priority {
            return Some(b.clone());
        }

        // 5. If same style, source priority:
        // Cell > Row > RowGroup > Column > ColumnGroup > Table
        if a.source > b.source {
            return Some(a.clone());
        }
        if b.source > a.source {
            return Some(b.clone());
        }

        // 6. Same priority - prefer first one (left/top in LTR)
        Some(a.clone())
    }
}

/// Get border information for a node
fn get_border_info<T: ParsedFontTrait>(
    ctx: &LayoutContext<'_, T>,
    node: &LayoutNode,
    source: BorderSource,
) -> (BorderInfo, BorderInfo, BorderInfo, BorderInfo) {
    use azul_css::props::{
        basic::{
            pixel::{PhysicalSize, PropertyContext, ResolutionContext},
            ColorU,
        },
        style::BorderStyle,
    };
    use get_element_font_size;
    use get_parent_font_size;
    use get_root_font_size;

    let default_border = BorderInfo::new(
        0.0,
        BorderStyle::None,
        ColorU {
            r: 0,
            g: 0,
            b: 0,
            a: 0,
        },
        source,
    );

    let Some(dom_id) = node.dom_node_id else {
        return (
            default_border.clone(),
            default_border.clone(),
            default_border.clone(),
            default_border.clone(),
        );
    };

    let node_data = &ctx.styled_dom.node_data.as_container()[dom_id];
    let node_state = StyledNodeState::default();
    let cache = &ctx.styled_dom.css_property_cache.ptr;

    // Create resolution context for border-width (em/rem support, no % support)
    let element_font_size = get_element_font_size(ctx.styled_dom, dom_id, &node_state);
    let parent_font_size = get_parent_font_size(ctx.styled_dom, dom_id, &node_state);
    let root_font_size = get_root_font_size(ctx.styled_dom, &node_state);

    let resolution_context = ResolutionContext {
        element_font_size,
        parent_font_size,
        root_font_size,
        // Not used for border-width
        containing_block_size: PhysicalSize::new(0.0, 0.0),
        // Not used for border-width
        element_size: None,
        viewport_size: PhysicalSize::new(0.0, 0.0),
    };

    // Top border
    let top = cache
        .get_border_top_style(node_data, &dom_id, &node_state)
        .and_then(|s| s.get_property())
        .map(|style_val| {
            let width = cache
                .get_border_top_width(node_data, &dom_id, &node_state)
                .and_then(|w| w.get_property())
                .map(|w| {
                    w.inner
                        .resolve_with_context(&resolution_context, PropertyContext::BorderWidth)
                })
                .unwrap_or(0.0);
            let color = cache
                .get_border_top_color(node_data, &dom_id, &node_state)
                .and_then(|c| c.get_property())
                .map(|c| c.inner)
                .unwrap_or(ColorU {
                    r: 0,
                    g: 0,
                    b: 0,
                    a: 255,
                });
            BorderInfo::new(width, style_val.inner, color, source)
        })
        .unwrap_or_else(|| default_border.clone());

    // Right border
    let right = cache
        .get_border_right_style(node_data, &dom_id, &node_state)
        .and_then(|s| s.get_property())
        .map(|style_val| {
            let width = cache
                .get_border_right_width(node_data, &dom_id, &node_state)
                .and_then(|w| w.get_property())
                .map(|w| {
                    w.inner
                        .resolve_with_context(&resolution_context, PropertyContext::BorderWidth)
                })
                .unwrap_or(0.0);
            let color = cache
                .get_border_right_color(node_data, &dom_id, &node_state)
                .and_then(|c| c.get_property())
                .map(|c| c.inner)
                .unwrap_or(ColorU {
                    r: 0,
                    g: 0,
                    b: 0,
                    a: 255,
                });
            BorderInfo::new(width, style_val.inner, color, source)
        })
        .unwrap_or_else(|| default_border.clone());

    // Bottom border
    let bottom = cache
        .get_border_bottom_style(node_data, &dom_id, &node_state)
        .and_then(|s| s.get_property())
        .map(|style_val| {
            let width = cache
                .get_border_bottom_width(node_data, &dom_id, &node_state)
                .and_then(|w| w.get_property())
                .map(|w| {
                    w.inner
                        .resolve_with_context(&resolution_context, PropertyContext::BorderWidth)
                })
                .unwrap_or(0.0);
            let color = cache
                .get_border_bottom_color(node_data, &dom_id, &node_state)
                .and_then(|c| c.get_property())
                .map(|c| c.inner)
                .unwrap_or(ColorU {
                    r: 0,
                    g: 0,
                    b: 0,
                    a: 255,
                });
            BorderInfo::new(width, style_val.inner, color, source)
        })
        .unwrap_or_else(|| default_border.clone());

    // Left border
    let left = cache
        .get_border_left_style(node_data, &dom_id, &node_state)
        .and_then(|s| s.get_property())
        .map(|style_val| {
            let width = cache
                .get_border_left_width(node_data, &dom_id, &node_state)
                .and_then(|w| w.get_property())
                .map(|w| {
                    w.inner
                        .resolve_with_context(&resolution_context, PropertyContext::BorderWidth)
                })
                .unwrap_or(0.0);
            let color = cache
                .get_border_left_color(node_data, &dom_id, &node_state)
                .and_then(|c| c.get_property())
                .map(|c| c.inner)
                .unwrap_or(ColorU {
                    r: 0,
                    g: 0,
                    b: 0,
                    a: 255,
                });
            BorderInfo::new(width, style_val.inner, color, source)
        })
        .unwrap_or_else(|| default_border.clone());

    (top, right, bottom, left)
}

/// Get the table-layout property for a table node
fn get_table_layout_property<T: ParsedFontTrait>(
    ctx: &LayoutContext<'_, T>,
    node: &LayoutNode,
) -> LayoutTableLayout {
    let Some(dom_id) = node.dom_node_id else {
        return LayoutTableLayout::Auto;
    };

    let node_data = &ctx.styled_dom.node_data.as_container()[dom_id];
    let node_state = StyledNodeState::default();

    ctx.styled_dom
        .css_property_cache
        .ptr
        .get_table_layout(node_data, &dom_id, &node_state)
        .and_then(|prop| prop.get_property().copied())
        .unwrap_or(LayoutTableLayout::Auto)
}

/// Get the border-collapse property for a table node
fn get_border_collapse_property<T: ParsedFontTrait>(
    ctx: &LayoutContext<'_, T>,
    node: &LayoutNode,
) -> StyleBorderCollapse {
    let Some(dom_id) = node.dom_node_id else {
        return StyleBorderCollapse::Separate;
    };

    let node_data = &ctx.styled_dom.node_data.as_container()[dom_id];
    let node_state = StyledNodeState::default();

    ctx.styled_dom
        .css_property_cache
        .ptr
        .get_border_collapse(node_data, &dom_id, &node_state)
        .and_then(|prop| prop.get_property().copied())
        .unwrap_or(StyleBorderCollapse::Separate)
}

/// Get the border-spacing property for a table node
fn get_border_spacing_property<T: ParsedFontTrait>(
    ctx: &LayoutContext<'_, T>,
    node: &LayoutNode,
) -> LayoutBorderSpacing {
    if let Some(dom_id) = node.dom_node_id {
        let node_data = &ctx.styled_dom.node_data.as_container()[dom_id];
        let node_state = StyledNodeState::default();

        if let Some(prop) = ctx.styled_dom.css_property_cache.ptr.get_border_spacing(
            node_data,
            &dom_id,
            &node_state,
        ) {
            if let Some(value) = prop.get_property() {
                return *value;
            }
        }
    }

    LayoutBorderSpacing::default() // Default: 0
}

/// CSS 2.2 Section 17.4 - Tables in the visual formatting model:
///
/// "The caption box is a block box that retains its own content, padding,
/// border, and margin areas. The caption-side property specifies the position
/// of the caption box with respect to the table box."
///
/// Get the caption-side property for a table node.
/// Returns Top (default) or Bottom.
fn get_caption_side_property<T: ParsedFontTrait>(
    ctx: &LayoutContext<'_, T>,
    node: &LayoutNode,
) -> StyleCaptionSide {
    if let Some(dom_id) = node.dom_node_id {
        let node_data = &ctx.styled_dom.node_data.as_container()[dom_id];
        let node_state = StyledNodeState::default();

        if let Some(prop) =
            ctx.styled_dom
                .css_property_cache
                .ptr
                .get_caption_side(node_data, &dom_id, &node_state)
        {
            if let Some(value) = prop.get_property() {
                return *value;
            }
        }
    }

    StyleCaptionSide::Top // Default per CSS 2.2
}

/// CSS 2.2 Section 17.6 - Dynamic row and column effects:
///
/// "The 'visibility' value 'collapse' removes a row or column from display,
/// but it has a different effect than 'visibility: hidden' on other elements.
/// When a row or column is collapsed, the space normally occupied by the row
/// or column is removed."
///
/// Check if a node has visibility:collapse set.
///
/// This is used for table rows and columns to optimize dynamic hiding.
fn is_visibility_collapsed<T: ParsedFontTrait>(
    ctx: &LayoutContext<'_, T>,
    node: &LayoutNode,
) -> bool {
    if let Some(dom_id) = node.dom_node_id {
        let node_data = &ctx.styled_dom.node_data.as_container()[dom_id];
        let node_state = StyledNodeState::default();

        if let Some(prop) =
            ctx.styled_dom
                .css_property_cache
                .ptr
                .get_visibility(node_data, &dom_id, &node_state)
        {
            if let Some(value) = prop.get_property() {
                return matches!(value, StyleVisibility::Collapse);
            }
        }
    }

    false
}

/// CSS 2.2 Section 17.6.1.1 - Borders and Backgrounds around empty cells
///
/// In the separated borders model, the 'empty-cells' property controls the rendering of
/// borders and backgrounds around cells that have no visible content. Empty means it has no
/// children, or has children that are only collapsed whitespace."
///
/// Check if a table cell is empty (has no visible content).
///
/// This is used by the rendering pipeline to decide whether to paint borders/backgrounds
/// when empty-cells: hide is set in separated border model.
///
/// A cell is considered empty if:
///
/// - It has no children, OR
/// - It has children but no inline_layout_result (no rendered content)
///
/// Note: Full whitespace detection would require checking text content during rendering.
/// This function provides a basic check suitable for layout phase.
fn is_cell_empty(tree: &LayoutTree, cell_index: usize) -> bool {
    let cell_node = match tree.get(cell_index) {
        Some(node) => node,
        None => return true, // Invalid cell is considered empty
    };

    // No children = empty
    if cell_node.children.is_empty() {
        return true;
    }

    // If cell has an inline layout result, check if it's empty
    if let Some(ref cached_layout) = cell_node.inline_layout_result {
        // Check if inline layout has any rendered content
        // Empty inline layouts have no items (glyphs/fragments)
        // Note: This is a heuristic - full detection requires text content analysis
        return cached_layout.layout.items.is_empty();
    }

    // Check if all children have no content
    // A more thorough check would recursively examine all descendants
    //
    // For now, we use a simple heuristic: if there are children, assume not empty
    // unless proven otherwise by inline_layout_result

    // Cell with children but no inline layout = likely has block-level content = not empty
    false
}

/// Main function to layout a table formatting context
pub fn layout_table_fc<T: ParsedFontTrait>(
    ctx: &mut LayoutContext<'_, T>,
    tree: &mut LayoutTree,
    text_cache: &mut crate::font_traits::TextLayoutCache,
    node_index: usize,
    constraints: &LayoutConstraints,
) -> Result<LayoutOutput> {
    debug_log!(ctx, "Laying out table");

    debug_table_layout!(
        ctx,
        "node_index={}, available_size={:?}, writing_mode={:?}",
        node_index,
        constraints.available_size,
        constraints.writing_mode
    );

    // Multi-pass table layout algorithm:
    //
    // 1. Analyze table structure - identify rows, cells, columns
    // 2. Determine table-layout property (fixed vs auto)
    // 3. Calculate column widths
    // 4. Layout cells and calculate row heights
    // 5. Position cells in final grid

    // Get the table node to read CSS properties
    let table_node = tree
        .get(node_index)
        .ok_or(LayoutError::InvalidTree)?
        .clone();

    // Calculate the table's border-box width for column distribution
    // This accounts for the table's own width property (e.g., width: 100%)
    let table_border_box_width = if let Some(dom_id) = table_node.dom_node_id {
        // Use calculate_used_size_for_node to resolve table width (respects width:100%)
        let intrinsic = table_node.intrinsic_sizes.clone().unwrap_or_default();
        let containing_block_size = LogicalSize {
            width: constraints.available_size.width,
            height: constraints.available_size.height,
        };

        let table_size = crate::solver3::sizing::calculate_used_size_for_node(
            ctx.styled_dom,
            Some(dom_id),
            containing_block_size,
            intrinsic,
            &table_node.box_props,
        )?;

        table_size.width
    } else {
        constraints.available_size.width
    };

    // Subtract padding and border to get content-box width for column distribution
    let table_content_box_width = {
        let padding_width = table_node.box_props.padding.left + table_node.box_props.padding.right;
        let border_width = table_node.box_props.border.left + table_node.box_props.border.right;
        (table_border_box_width - padding_width - border_width).max(0.0)
    };

    debug_table_layout!(ctx, "Table Layout Debug");
    debug_table_layout!(ctx, "Node index: {}", node_index);
    debug_table_layout!(
        ctx,
        "Available size from parent: {:.2} x {:.2}",
        constraints.available_size.width,
        constraints.available_size.height
    );
    debug_table_layout!(ctx, "Table border-box width: {:.2}", table_border_box_width);
    debug_table_layout!(
        ctx,
        "Table content-box width: {:.2}",
        table_content_box_width
    );
    debug_table_layout!(
        ctx,
        "Table padding: L={:.2} R={:.2}",
        table_node.box_props.padding.left,
        table_node.box_props.padding.right
    );
    debug_table_layout!(
        ctx,
        "Table border: L={:.2} R={:.2}",
        table_node.box_props.border.left,
        table_node.box_props.border.right
    );
    debug_table_layout!(ctx, "=");

    // Phase 1: Analyze table structure
    let mut table_ctx = analyze_table_structure(tree, node_index, ctx)?;

    // Phase 2: Read CSS properties and determine layout algorithm
    let table_layout = get_table_layout_property(ctx, &table_node);
    table_ctx.use_fixed_layout = matches!(table_layout, LayoutTableLayout::Fixed);

    // Read border properties
    table_ctx.border_collapse = get_border_collapse_property(ctx, &table_node);
    table_ctx.border_spacing = get_border_spacing_property(ctx, &table_node);

    debug_log!(
        ctx,
        "Table layout: {:?}, border-collapse: {:?}, border-spacing: {:?}",
        table_layout,
        table_ctx.border_collapse,
        table_ctx.border_spacing
    );

    // Phase 3: Calculate column widths
    if table_ctx.use_fixed_layout {
        // DEBUG: Log available width passed into fixed column calculation
        debug_table_layout!(
            ctx,
            "FIXED layout: table_content_box_width={:.2}",
            table_content_box_width
        );
        calculate_column_widths_fixed(ctx, &mut table_ctx, table_content_box_width);
    } else {
        // Pass table_content_box_width for column distribution in auto layout
        calculate_column_widths_auto_with_width(
            &mut table_ctx,
            tree,
            text_cache,
            ctx,
            constraints,
            table_content_box_width,
        )?;
    }

    debug_table_layout!(ctx, "After column width calculation:");
    debug_table_layout!(ctx, "  Number of columns: {}", table_ctx.columns.len());
    for (i, col) in table_ctx.columns.iter().enumerate() {
        debug_table_layout!(
            ctx,
            "  Column {}: width={:.2}",
            i,
            col.computed_width.unwrap_or(0.0)
        );
    }
    let total_col_width: f32 = table_ctx
        .columns
        .iter()
        .filter_map(|c| c.computed_width)
        .sum();
    debug_table_layout!(ctx, "  Total column width: {:.2}", total_col_width);

    // Phase 4: Calculate row heights based on cell content
    calculate_row_heights(&mut table_ctx, tree, text_cache, ctx, constraints)?;

    // Phase 5: Position cells in final grid and collect positions
    let mut cell_positions =
        position_table_cells(&mut table_ctx, tree, ctx, node_index, constraints)?;

    // Calculate final table size including border-spacing
    let mut table_width: f32 = table_ctx
        .columns
        .iter()
        .filter_map(|col| col.computed_width)
        .sum();
    let mut table_height: f32 = table_ctx.row_heights.iter().sum();

    debug_table_layout!(
        ctx,
        "After calculate_row_heights: table_height={:.2}, row_heights={:?}",
        table_height,
        table_ctx.row_heights
    );

    // Add border-spacing to table size if border-collapse is separate
    if table_ctx.border_collapse == StyleBorderCollapse::Separate {
        use get_element_font_size;
        use get_parent_font_size;
        use get_root_font_size;
        use PhysicalSize;
        use PropertyContext;
        use ResolutionContext;

        let styled_dom = ctx.styled_dom;
        let table_id = tree.nodes[node_index].dom_node_id.unwrap();
        let table_state = &styled_dom.styled_nodes.as_container()[table_id].styled_node_state;

        let spacing_context = ResolutionContext {
            element_font_size: get_element_font_size(styled_dom, table_id, table_state),
            parent_font_size: get_parent_font_size(styled_dom, table_id, table_state),
            root_font_size: get_root_font_size(styled_dom, table_state),
            containing_block_size: PhysicalSize::new(0.0, 0.0),
            element_size: None,
            // TODO: Get actual DPI scale from ctx
            viewport_size: PhysicalSize::new(0.0, 0.0),
        };

        let h_spacing = table_ctx
            .border_spacing
            .horizontal
            .resolve_with_context(&spacing_context, PropertyContext::Other);
        let v_spacing = table_ctx
            .border_spacing
            .vertical
            .resolve_with_context(&spacing_context, PropertyContext::Other);

        // Add spacing: left + (n-1 between columns) + right = n+1 spacings
        let num_cols = table_ctx.columns.len();
        if num_cols > 0 {
            table_width += h_spacing * (num_cols + 1) as f32;
        }

        // Add spacing: top + (n-1 between rows) + bottom = n+1 spacings
        if table_ctx.num_rows > 0 {
            table_height += v_spacing * (table_ctx.num_rows + 1) as f32;
        }
    }

    // CSS 2.2 Section 17.4: Layout and position the caption if present
    //
    // "The caption box is a block box that retains its own content,
    // padding, border, and margin areas."
    let caption_side = get_caption_side_property(ctx, &table_node);
    let mut caption_height = 0.0;
    let mut table_y_offset = 0.0;

    if let Some(caption_idx) = table_ctx.caption_index {
        debug_log!(
            ctx,
            "Laying out caption with caption-side: {:?}",
            caption_side
        );

        // Layout caption as a block with the table's width as available width
        let caption_constraints = LayoutConstraints {
            available_size: LogicalSize {
                width: table_width,
                height: constraints.available_size.height,
            },
            writing_mode: constraints.writing_mode,
            bfc_state: None, // Caption creates its own BFC
            text_align: constraints.text_align,
            containing_block_size: constraints.containing_block_size,
            available_width_type: Text3AvailableSpace::Definite(table_width),
        };

        // Layout the caption node
        let mut empty_float_cache = std::collections::BTreeMap::new();
        let caption_result = layout_formatting_context(
            ctx,
            tree,
            text_cache,
            caption_idx,
            &caption_constraints,
            &mut empty_float_cache,
        )?;
        caption_height = caption_result.output.overflow_size.height;

        // Position caption based on caption-side property
        let caption_position = match caption_side {
            StyleCaptionSide::Top => {
                // Caption on top: position at y=0, table starts below caption
                table_y_offset = caption_height;
                LogicalPosition { x: 0.0, y: 0.0 }
            }
            StyleCaptionSide::Bottom => {
                // Caption on bottom: table starts at y=0, caption below table
                LogicalPosition {
                    x: 0.0,
                    y: table_height,
                }
            }
        };

        // Add caption position to the positions map
        cell_positions.insert(caption_idx, caption_position);

        debug_log!(
            ctx,
            "Caption positioned at x={:.2}, y={:.2}, height={:.2}",
            caption_position.x,
            caption_position.y,
            caption_height
        );
    }

    // Adjust all table cell positions if caption is on top
    if table_y_offset > 0.0 {
        debug_log!(
            ctx,
            "Adjusting table cells by y offset: {:.2}",
            table_y_offset
        );

        // Adjust cell positions in the map
        for cell_info in &table_ctx.cells {
            if let Some(pos) = cell_positions.get_mut(&cell_info.node_index) {
                pos.y += table_y_offset;
            }
        }
    }

    // Total table height includes caption
    let total_height = table_height + caption_height;

    debug_table_layout!(ctx, "Final table dimensions:");
    debug_table_layout!(ctx, "  Content width (columns): {:.2}", table_width);
    debug_table_layout!(ctx, "  Content height (rows): {:.2}", table_height);
    debug_table_layout!(ctx, "  Caption height: {:.2}", caption_height);
    debug_table_layout!(ctx, "  Total height: {:.2}", total_height);
    debug_table_layout!(ctx, "End Table Debug");

    // Create output with the table's final size and cell positions
    let output = LayoutOutput {
        overflow_size: LogicalSize {
            width: table_width,
            height: total_height,
        },
        // Cell positions calculated in position_table_cells
        positions: cell_positions,
        // Tables don't have a baseline
        baseline: None,
    };

    Ok(output)
}

/// Analyze the table structure to identify rows, cells, and columns
fn analyze_table_structure<T: ParsedFontTrait>(
    tree: &LayoutTree,
    table_index: usize,
    ctx: &mut LayoutContext<'_, T>,
) -> Result<TableLayoutContext> {
    let mut table_ctx = TableLayoutContext::new();

    let table_node = tree.get(table_index).ok_or(LayoutError::InvalidTree)?;

    // CSS 2.2 Section 17.4: A table may have one table-caption child.
    // Traverse children to find caption, columns/colgroups, rows, and row groups
    for &child_idx in &table_node.children {
        if let Some(child) = tree.get(child_idx) {
            // Check if this is a table caption
            if matches!(child.formatting_context, FormattingContext::TableCaption) {
                debug_log!(ctx, "Found table caption at index {}", child_idx);
                table_ctx.caption_index = Some(child_idx);
                continue;
            }

            // CSS 2.2 Section 17.2: Check for column groups
            if matches!(
                child.formatting_context,
                FormattingContext::TableColumnGroup
            ) {
                analyze_table_colgroup(tree, child_idx, &mut table_ctx, ctx)?;
                continue;
            }

            // Check if this is a table row or row group
            match child.formatting_context {
                FormattingContext::TableRow => {
                    analyze_table_row(tree, child_idx, &mut table_ctx, ctx)?;
                }
                FormattingContext::TableRowGroup => {
                    // Process rows within the row group
                    for &row_idx in &child.children {
                        if let Some(row) = tree.get(row_idx) {
                            if matches!(row.formatting_context, FormattingContext::TableRow) {
                                analyze_table_row(tree, row_idx, &mut table_ctx, ctx)?;
                            }
                        }
                    }
                }
                _ => {}
            }
        }
    }

    debug_log!(
        ctx,
        "Table structure: {} rows, {} columns, {} cells{}",
        table_ctx.num_rows,
        table_ctx.columns.len(),
        table_ctx.cells.len(),
        if table_ctx.caption_index.is_some() {
            ", has caption"
        } else {
            ""
        }
    );

    Ok(table_ctx)
}

/// Analyze a table column group to identify columns and track collapsed columns
///
/// - CSS 2.2 Section 17.2: Column groups contain columns
/// - CSS 2.2 Section 17.6: Columns can have visibility:collapse
fn analyze_table_colgroup<T: ParsedFontTrait>(
    tree: &LayoutTree,
    colgroup_index: usize,
    table_ctx: &mut TableLayoutContext,
    ctx: &mut LayoutContext<'_, T>,
) -> Result<()> {
    let colgroup_node = tree.get(colgroup_index).ok_or(LayoutError::InvalidTree)?;

    // Check if the colgroup itself has visibility:collapse
    if is_visibility_collapsed(ctx, colgroup_node) {
        // All columns in this group should be collapsed
        // TODO: For now, just mark the group (actual column indices will be determined later)
        debug_log!(
            ctx,
            "Column group at index {} has visibility:collapse",
            colgroup_index
        );
    }

    // Check for individual column elements within the group
    for &col_idx in &colgroup_node.children {
        if let Some(col_node) = tree.get(col_idx) {
            // Note: Individual columns don't have a FormattingContext::TableColumn
            // They are represented as children of TableColumnGroup
            // Check visibility:collapse on each column
            if is_visibility_collapsed(ctx, col_node) {
                // We need to determine the actual column index this represents
                // For now, we'll track it during cell analysis
                debug_log!(ctx, "Column at index {} has visibility:collapse", col_idx);
            }
        }
    }

    Ok(())
}

/// Analyze a table row to identify cells and update column count
fn analyze_table_row<T: ParsedFontTrait>(
    tree: &LayoutTree,
    row_index: usize,
    table_ctx: &mut TableLayoutContext,
    ctx: &mut LayoutContext<'_, T>,
) -> Result<()> {
    let row_node = tree.get(row_index).ok_or(LayoutError::InvalidTree)?;
    let row_num = table_ctx.num_rows;
    table_ctx.num_rows += 1;

    // CSS 2.2 Section 17.6: Check if this row has visibility:collapse
    if is_visibility_collapsed(ctx, row_node) {
        debug_log!(ctx, "Row {} has visibility:collapse", row_num);
        table_ctx.collapsed_rows.insert(row_num);
    }

    let mut col_index = 0;

    for &cell_idx in &row_node.children {
        if let Some(cell) = tree.get(cell_idx) {
            if matches!(cell.formatting_context, FormattingContext::TableCell) {
                // Get colspan and rowspan (TODO: from CSS properties)
                let colspan = 1; // TODO: Get from CSS
                let rowspan = 1; // TODO: Get from CSS

                let cell_info = TableCellInfo {
                    node_index: cell_idx,
                    column: col_index,
                    colspan,
                    row: row_num,
                    rowspan,
                };

                table_ctx.cells.push(cell_info);

                // Update column count
                let max_col = col_index + colspan;
                while table_ctx.columns.len() < max_col {
                    table_ctx.columns.push(TableColumnInfo {
                        min_width: 0.0,
                        max_width: 0.0,
                        computed_width: None,
                    });
                }

                col_index += colspan;
            }
        }
    }

    Ok(())
}

/// Calculate column widths using the fixed table layout algorithm
///
/// CSS 2.2 Section 17.5.2.1: In fixed table layout, the table width is
/// not dependent on cell contents
///
/// CSS 2.2 Section 17.6: Columns with visibility:collapse are excluded
/// from width calculations
fn calculate_column_widths_fixed<T: ParsedFontTrait>(
    ctx: &mut LayoutContext<'_, T>,
    table_ctx: &mut TableLayoutContext,
    available_width: f32,
) {
    debug_table_layout!(
        ctx,
        "calculate_column_widths_fixed: num_cols={}, available_width={:.2}",
        table_ctx.columns.len(),
        available_width
    );

    // Fixed layout: distribute width equally among non-collapsed columns
    // TODO: Respect column width properties and first-row cell widths
    let num_cols = table_ctx.columns.len();
    if num_cols == 0 {
        return;
    }

    // Count non-collapsed columns
    let num_visible_cols = num_cols - table_ctx.collapsed_columns.len();
    if num_visible_cols == 0 {
        // All columns collapsed - set all to zero width
        for col in &mut table_ctx.columns {
            col.computed_width = Some(0.0);
        }
        return;
    }

    // Distribute width only among visible columns
    let col_width = available_width / num_visible_cols as f32;
    for (col_idx, col) in table_ctx.columns.iter_mut().enumerate() {
        if table_ctx.collapsed_columns.contains(&col_idx) {
            col.computed_width = Some(0.0);
        } else {
            col.computed_width = Some(col_width);
        }
    }
}

/// Measure a cell's minimum content width (with maximum wrapping)
fn measure_cell_min_content_width<T: ParsedFontTrait>(
    ctx: &mut LayoutContext<'_, T>,
    tree: &mut LayoutTree,
    text_cache: &mut crate::font_traits::TextLayoutCache,
    cell_index: usize,
    constraints: &LayoutConstraints,
) -> Result<f32> {
    // CSS 2.2 Section 17.5.2.2: "Calculate the minimum content width (MCW) of each cell"
    //
    // Min-content width is the width with maximum wrapping.
    // Use AvailableSpace::MinContent to signal intrinsic min-content sizing to the
    // text layout engine.
    use crate::text3::cache::AvailableSpace;
    let min_constraints = LayoutConstraints {
        available_size: LogicalSize {
            width: AvailableSpace::MinContent.to_f32_for_layout(),
            height: f32::INFINITY,
        },
        writing_mode: constraints.writing_mode,
        bfc_state: None, // Don't propagate BFC state for measurement
        text_align: constraints.text_align,
        containing_block_size: constraints.containing_block_size,
        // CRITICAL: Mark this as min-content measurement, not definite width!
        // This ensures the cached layout won't be incorrectly reused for final rendering.
        available_width_type: Text3AvailableSpace::MinContent,
    };

    let mut temp_positions = BTreeMap::new();
    let mut temp_scrollbar_reflow = false;
    let mut temp_float_cache = std::collections::BTreeMap::new();

    crate::solver3::cache::calculate_layout_for_subtree(
        ctx,
        tree,
        text_cache,
        cell_index,
        LogicalPosition::zero(),
        min_constraints.available_size,
        &mut temp_positions,
        &mut temp_scrollbar_reflow,
        &mut temp_float_cache,
    )?;

    let cell_node = tree.get(cell_index).ok_or(LayoutError::InvalidTree)?;
    let size = cell_node.used_size.unwrap_or_default();

    // Add padding and border to get the total minimum width
    let padding = &cell_node.box_props.padding;
    let border = &cell_node.box_props.border;
    let writing_mode = constraints.writing_mode;

    let min_width = size.width
        + padding.cross_start(writing_mode)
        + padding.cross_end(writing_mode)
        + border.cross_start(writing_mode)
        + border.cross_end(writing_mode);

    Ok(min_width)
}

/// Measure a cell's maximum content width (without wrapping)
fn measure_cell_max_content_width<T: ParsedFontTrait>(
    ctx: &mut LayoutContext<'_, T>,
    tree: &mut LayoutTree,
    text_cache: &mut crate::font_traits::TextLayoutCache,
    cell_index: usize,
    constraints: &LayoutConstraints,
) -> Result<f32> {
    // CSS 2.2 Section 17.5.2.2: "Calculate the maximum content width (MCW) of each cell"
    //
    // Max-content width is the width without any wrapping.
    // Use AvailableSpace::MaxContent to signal intrinsic max-content sizing to
    // the text layout engine.
    use crate::text3::cache::AvailableSpace;
    let max_constraints = LayoutConstraints {
        available_size: LogicalSize {
            width: AvailableSpace::MaxContent.to_f32_for_layout(),
            height: f32::INFINITY,
        },
        writing_mode: constraints.writing_mode,
        bfc_state: None, // Don't propagate BFC state for measurement
        text_align: constraints.text_align,
        containing_block_size: constraints.containing_block_size,
        // CRITICAL: Mark this as max-content measurement, not definite width!
        // This ensures the cached layout won't be incorrectly reused for final rendering.
        available_width_type: Text3AvailableSpace::MaxContent,
    };

    let mut temp_positions = BTreeMap::new();
    let mut temp_scrollbar_reflow = false;
    let mut temp_float_cache = std::collections::BTreeMap::new();

    crate::solver3::cache::calculate_layout_for_subtree(
        ctx,
        tree,
        text_cache,
        cell_index,
        LogicalPosition::zero(),
        max_constraints.available_size,
        &mut temp_positions,
        &mut temp_scrollbar_reflow,
        &mut temp_float_cache,
    )?;

    let cell_node = tree.get(cell_index).ok_or(LayoutError::InvalidTree)?;
    let size = cell_node.used_size.unwrap_or_default();

    // Add padding and border to get the total maximum width
    let padding = &cell_node.box_props.padding;
    let border = &cell_node.box_props.border;
    let writing_mode = constraints.writing_mode;

    let max_width = size.width
        + padding.cross_start(writing_mode)
        + padding.cross_end(writing_mode)
        + border.cross_start(writing_mode)
        + border.cross_end(writing_mode);

    Ok(max_width)
}

/// Calculate column widths using the auto table layout algorithm
fn calculate_column_widths_auto<T: ParsedFontTrait>(
    table_ctx: &mut TableLayoutContext,
    tree: &mut LayoutTree,
    text_cache: &mut crate::font_traits::TextLayoutCache,
    ctx: &mut LayoutContext<'_, T>,
    constraints: &LayoutConstraints,
) -> Result<()> {
    calculate_column_widths_auto_with_width(
        table_ctx,
        tree,
        text_cache,
        ctx,
        constraints,
        constraints.available_size.width,
    )
}

/// Calculate column widths using the auto table layout algorithm with explicit table width
fn calculate_column_widths_auto_with_width<T: ParsedFontTrait>(
    table_ctx: &mut TableLayoutContext,
    tree: &mut LayoutTree,
    text_cache: &mut crate::font_traits::TextLayoutCache,
    ctx: &mut LayoutContext<'_, T>,
    constraints: &LayoutConstraints,
    table_width: f32,
) -> Result<()> {
    // Auto layout: calculate min/max content width for each cell
    let num_cols = table_ctx.columns.len();
    if num_cols == 0 {
        return Ok(());
    }

    // Step 1: Measure all cells to determine column min/max widths
    // CSS 2.2 Section 17.6: Skip cells in collapsed columns
    for cell_info in &table_ctx.cells {
        // Skip cells in collapsed columns
        if table_ctx.collapsed_columns.contains(&cell_info.column) {
            continue;
        }

        // Skip cells that span into collapsed columns
        let mut spans_collapsed = false;
        for col_offset in 0..cell_info.colspan {
            if table_ctx
                .collapsed_columns
                .contains(&(cell_info.column + col_offset))
            {
                spans_collapsed = true;
                break;
            }
        }
        if spans_collapsed {
            continue;
        }

        let min_width = measure_cell_min_content_width(
            ctx,
            tree,
            text_cache,
            cell_info.node_index,
            constraints,
        )?;

        let max_width = measure_cell_max_content_width(
            ctx,
            tree,
            text_cache,
            cell_info.node_index,
            constraints,
        )?;

        // Handle single-column cells
        if cell_info.colspan == 1 {
            let col = &mut table_ctx.columns[cell_info.column];
            col.min_width = col.min_width.max(min_width);
            col.max_width = col.max_width.max(max_width);
        } else {
            // Handle multi-column cells (colspan > 1)
            // Distribute the cell's min/max width across the spanned columns
            distribute_cell_width_across_columns(
                &mut table_ctx.columns,
                cell_info.column,
                cell_info.colspan,
                min_width,
                max_width,
                &table_ctx.collapsed_columns,
            );
        }
    }

    // Step 2: Calculate final column widths based on available space
    // Exclude collapsed columns from total width calculations
    let total_min_width: f32 = table_ctx
        .columns
        .iter()
        .enumerate()
        .filter(|(idx, _)| !table_ctx.collapsed_columns.contains(idx))
        .map(|(_, c)| c.min_width)
        .sum();
    let total_max_width: f32 = table_ctx
        .columns
        .iter()
        .enumerate()
        .filter(|(idx, _)| !table_ctx.collapsed_columns.contains(idx))
        .map(|(_, c)| c.max_width)
        .sum();
    let available_width = table_width; // Use table's content-box width, not constraints

    debug_table_layout!(
        ctx,
        "calculate_column_widths_auto: min={:.2}, max={:.2}, table_width={:.2}",
        total_min_width,
        total_max_width,
        table_width
    );

    // Handle infinity and NaN cases
    if !total_max_width.is_finite() || !available_width.is_finite() {
        // If max_width is infinite or unavailable, distribute available width equally
        let num_non_collapsed = table_ctx.columns.len() - table_ctx.collapsed_columns.len();
        let width_per_column = if num_non_collapsed > 0 {
            available_width / num_non_collapsed as f32
        } else {
            0.0
        };

        for (col_idx, col) in table_ctx.columns.iter_mut().enumerate() {
            if table_ctx.collapsed_columns.contains(&col_idx) {
                col.computed_width = Some(0.0);
            } else {
                // Use the larger of min_width and equal distribution
                col.computed_width = Some(col.min_width.max(width_per_column));
            }
        }
    } else if available_width >= total_max_width {
        // Case 1: More space than max-content - distribute excess proportionally
        //
        // CSS 2.1 Section 17.5.2.2: Distribute extra space proportionally to
        // max-content widths
        let excess_width = available_width - total_max_width;

        // First pass: collect column info (max_width) to avoid borrowing issues
        let column_info: Vec<(usize, f32, bool)> = table_ctx
            .columns
            .iter()
            .enumerate()
            .map(|(idx, c)| (idx, c.max_width, table_ctx.collapsed_columns.contains(&idx)))
            .collect();

        // Calculate total weight for proportional distribution (use max_width as weight)
        let total_weight: f32 = column_info.iter()
            .filter(|(_, _, is_collapsed)| !is_collapsed)
            .map(|(_, max_w, _)| max_w.max(1.0)) // Avoid division by zero
            .sum();

        let num_non_collapsed = column_info
            .iter()
            .filter(|(_, _, is_collapsed)| !is_collapsed)
            .count();

        // Second pass: set computed widths
        for (col_idx, max_width, is_collapsed) in column_info {
            let col = &mut table_ctx.columns[col_idx];
            if is_collapsed {
                col.computed_width = Some(0.0);
            } else {
                // Start with max-content width, then add proportional share of excess
                let weight_factor = if total_weight > 0.0 {
                    max_width.max(1.0) / total_weight
                } else {
                    // If all columns have 0 max_width, distribute equally
                    1.0 / num_non_collapsed.max(1) as f32
                };

                let final_width = max_width + (excess_width * weight_factor);
                col.computed_width = Some(final_width);
            }
        }
    } else if available_width >= total_min_width {
        // Case 2: Between min and max - interpolate proportionally
        // Avoid division by zero if min == max
        let scale = if total_max_width > total_min_width {
            (available_width - total_min_width) / (total_max_width - total_min_width)
        } else {
            0.0 // If min == max, just use min width
        };
        for (col_idx, col) in table_ctx.columns.iter_mut().enumerate() {
            if table_ctx.collapsed_columns.contains(&col_idx) {
                col.computed_width = Some(0.0);
            } else {
                let interpolated = col.min_width + (col.max_width - col.min_width) * scale;
                col.computed_width = Some(interpolated);
            }
        }
    } else {
        // Case 3: Not enough space - scale down from min widths
        let scale = available_width / total_min_width;
        for (col_idx, col) in table_ctx.columns.iter_mut().enumerate() {
            if table_ctx.collapsed_columns.contains(&col_idx) {
                col.computed_width = Some(0.0);
            } else {
                col.computed_width = Some(col.min_width * scale);
            }
        }
    }

    Ok(())
}

/// Distribute a multi-column cell's width across the columns it spans
fn distribute_cell_width_across_columns(
    columns: &mut [TableColumnInfo],
    start_col: usize,
    colspan: usize,
    cell_min_width: f32,
    cell_max_width: f32,
    collapsed_columns: &std::collections::HashSet<usize>,
) {
    let end_col = start_col + colspan;
    if end_col > columns.len() {
        return;
    }

    // Calculate current total of spanned non-collapsed columns
    let current_min_total: f32 = columns[start_col..end_col]
        .iter()
        .enumerate()
        .filter(|(idx, _)| !collapsed_columns.contains(&(start_col + idx)))
        .map(|(_, c)| c.min_width)
        .sum();
    let current_max_total: f32 = columns[start_col..end_col]
        .iter()
        .enumerate()
        .filter(|(idx, _)| !collapsed_columns.contains(&(start_col + idx)))
        .map(|(_, c)| c.max_width)
        .sum();

    // Count non-collapsed columns in the span
    let num_visible_cols = (start_col..end_col)
        .filter(|idx| !collapsed_columns.contains(idx))
        .count();

    if num_visible_cols == 0 {
        return; // All spanned columns are collapsed
    }

    // Only distribute if the cell needs more space than currently available
    if cell_min_width > current_min_total {
        let extra_min = cell_min_width - current_min_total;
        let per_col = extra_min / num_visible_cols as f32;
        for (idx, col) in columns[start_col..end_col].iter_mut().enumerate() {
            if !collapsed_columns.contains(&(start_col + idx)) {
                col.min_width += per_col;
            }
        }
    }

    if cell_max_width > current_max_total {
        let extra_max = cell_max_width - current_max_total;
        let per_col = extra_max / num_visible_cols as f32;
        for (idx, col) in columns[start_col..end_col].iter_mut().enumerate() {
            if !collapsed_columns.contains(&(start_col + idx)) {
                col.max_width += per_col;
            }
        }
    }
}

/// Layout a cell with its computed column width to determine its content height
fn layout_cell_for_height<T: ParsedFontTrait>(
    ctx: &mut LayoutContext<'_, T>,
    tree: &mut LayoutTree,
    text_cache: &mut crate::font_traits::TextLayoutCache,
    cell_index: usize,
    cell_width: f32,
    constraints: &LayoutConstraints,
) -> Result<f32> {
    let cell_node = tree.get(cell_index).ok_or(LayoutError::InvalidTree)?;
    let cell_dom_id = cell_node.dom_node_id.ok_or(LayoutError::InvalidTree)?;

    // Check if cell has text content directly in DOM (not in LayoutTree)
    // Text nodes are intentionally not included in LayoutTree per CSS spec,
    // but we need to measure them for table cell height calculation.
    let has_text_children = cell_dom_id
        .az_children(&ctx.styled_dom.node_hierarchy.as_container())
        .any(|child_id| {
            let node_data = &ctx.styled_dom.node_data.as_container()[child_id];
            matches!(node_data.get_node_type(), NodeType::Text(_))
        });

    debug_table_layout!(
        ctx,
        "layout_cell_for_height: cell_index={}, has_text_children={}",
        cell_index,
        has_text_children
    );

    // Get padding and border to calculate content width
    let cell_node = tree.get(cell_index).ok_or(LayoutError::InvalidTree)?;
    let padding = &cell_node.box_props.padding;
    let border = &cell_node.box_props.border;
    let writing_mode = constraints.writing_mode;

    // cell_width is the border-box width (includes padding/border from column
    // width calculation) but layout functions need content-box width
    let content_width = cell_width
        - padding.cross_start(writing_mode)
        - padding.cross_end(writing_mode)
        - border.cross_start(writing_mode)
        - border.cross_end(writing_mode);

    debug_table_layout!(
        ctx,
        "Cell width: border_box={:.2}, content_box={:.2}",
        cell_width,
        content_width
    );

    let content_height = if has_text_children {
        // Cell contains text - use IFC to measure it
        debug_table_layout!(ctx, "Using IFC to measure text content");

        let cell_constraints = LayoutConstraints {
            available_size: LogicalSize {
                width: content_width, // Use content width, not border-box width
                height: f32::INFINITY,
            },
            writing_mode: constraints.writing_mode,
            bfc_state: None,
            text_align: constraints.text_align,
            containing_block_size: constraints.containing_block_size,
            // Use definite width for final cell layout!
            // This replaces any previous MinContent/MaxContent measurement.
            available_width_type: Text3AvailableSpace::Definite(content_width),
        };

        let output = layout_ifc(ctx, text_cache, tree, cell_index, &cell_constraints)?;

        debug_table_layout!(
            ctx,
            "IFC returned height={:.2}",
            output.overflow_size.height
        );

        output.overflow_size.height
    } else {
        // Cell contains block-level children or is empty - use regular layout
        debug_table_layout!(ctx, "Using regular layout for block children");

        let cell_constraints = LayoutConstraints {
            available_size: LogicalSize {
                width: content_width, // Use content width, not border-box width
                height: f32::INFINITY,
            },
            writing_mode: constraints.writing_mode,
            bfc_state: None,
            text_align: constraints.text_align,
            containing_block_size: constraints.containing_block_size,
            // Use Definite width for final cell layout!
            available_width_type: Text3AvailableSpace::Definite(content_width),
        };

        let mut temp_positions = BTreeMap::new();
        let mut temp_scrollbar_reflow = false;
        let mut temp_float_cache = std::collections::BTreeMap::new();

        crate::solver3::cache::calculate_layout_for_subtree(
            ctx,
            tree,
            text_cache,
            cell_index,
            LogicalPosition::zero(),
            cell_constraints.available_size,
            &mut temp_positions,
            &mut temp_scrollbar_reflow,
            &mut temp_float_cache,
        )?;

        let cell_node = tree.get(cell_index).ok_or(LayoutError::InvalidTree)?;
        cell_node.used_size.unwrap_or_default().height
    };

    // Add padding and border to get the total height
    let cell_node = tree.get(cell_index).ok_or(LayoutError::InvalidTree)?;
    let padding = &cell_node.box_props.padding;
    let border = &cell_node.box_props.border;
    let writing_mode = constraints.writing_mode;

    let total_height = content_height
        + padding.main_start(writing_mode)
        + padding.main_end(writing_mode)
        + border.main_start(writing_mode)
        + border.main_end(writing_mode);

    debug_table_layout!(
        ctx,
        "Cell total height: cell_index={}, content={:.2}, padding/border={:.2}, total={:.2}",
        cell_index,
        content_height,
        padding.main_start(writing_mode)
            + padding.main_end(writing_mode)
            + border.main_start(writing_mode)
            + border.main_end(writing_mode),
        total_height
    );

    Ok(total_height)
}

/// Calculate row heights based on cell content after column widths are determined
fn calculate_row_heights<T: ParsedFontTrait>(
    table_ctx: &mut TableLayoutContext,
    tree: &mut LayoutTree,
    text_cache: &mut crate::font_traits::TextLayoutCache,
    ctx: &mut LayoutContext<'_, T>,
    constraints: &LayoutConstraints,
) -> Result<()> {
    debug_table_layout!(
        ctx,
        "calculate_row_heights: num_rows={}, available_size={:?}",
        table_ctx.num_rows,
        constraints.available_size
    );

    // Initialize row heights
    table_ctx.row_heights = vec![0.0; table_ctx.num_rows];

    // CSS 2.2 Section 17.6: Set collapsed rows to height 0
    for &row_idx in &table_ctx.collapsed_rows {
        if row_idx < table_ctx.row_heights.len() {
            table_ctx.row_heights[row_idx] = 0.0;
        }
    }

    // First pass: Calculate heights for cells that don't span multiple rows
    for cell_info in &table_ctx.cells {
        // Skip cells in collapsed rows
        if table_ctx.collapsed_rows.contains(&cell_info.row) {
            continue;
        }

        // Get the cell's width (sum of column widths if colspan > 1)
        let mut cell_width = 0.0;
        for col_idx in cell_info.column..(cell_info.column + cell_info.colspan) {
            if let Some(col) = table_ctx.columns.get(col_idx) {
                if let Some(width) = col.computed_width {
                    cell_width += width;
                }
            }
        }

        debug_table_layout!(
            ctx,
            "Cell layout: node_index={}, row={}, col={}, width={:.2}",
            cell_info.node_index,
            cell_info.row,
            cell_info.column,
            cell_width
        );

        // Layout the cell to get its height
        let cell_height = layout_cell_for_height(
            ctx,
            tree,
            text_cache,
            cell_info.node_index,
            cell_width,
            constraints,
        )?;

        debug_table_layout!(
            ctx,
            "Cell height calculated: node_index={}, height={:.2}",
            cell_info.node_index,
            cell_height
        );

        // For single-row cells, update the row height
        if cell_info.rowspan == 1 {
            let current_height = table_ctx.row_heights[cell_info.row];
            table_ctx.row_heights[cell_info.row] = current_height.max(cell_height);
        }
    }

    // Second pass: Handle cells that span multiple rows (rowspan > 1)
    for cell_info in &table_ctx.cells {
        // Skip cells that start in collapsed rows
        if table_ctx.collapsed_rows.contains(&cell_info.row) {
            continue;
        }

        if cell_info.rowspan > 1 {
            // Get the cell's width
            let mut cell_width = 0.0;
            for col_idx in cell_info.column..(cell_info.column + cell_info.colspan) {
                if let Some(col) = table_ctx.columns.get(col_idx) {
                    if let Some(width) = col.computed_width {
                        cell_width += width;
                    }
                }
            }

            // Layout the cell to get its height
            let cell_height = layout_cell_for_height(
                ctx,
                tree,
                text_cache,
                cell_info.node_index,
                cell_width,
                constraints,
            )?;

            // Calculate the current total height of spanned rows (excluding collapsed rows)
            let end_row = cell_info.row + cell_info.rowspan;
            let current_total: f32 = table_ctx.row_heights[cell_info.row..end_row]
                .iter()
                .enumerate()
                .filter(|(idx, _)| !table_ctx.collapsed_rows.contains(&(cell_info.row + idx)))
                .map(|(_, height)| height)
                .sum();

            // If the cell needs more height, distribute extra height across
            // non-collapsed spanned rows
            if cell_height > current_total {
                let extra_height = cell_height - current_total;

                // Count non-collapsed rows in span
                let non_collapsed_rows = (cell_info.row..end_row)
                    .filter(|row_idx| !table_ctx.collapsed_rows.contains(row_idx))
                    .count();

                if non_collapsed_rows > 0 {
                    let per_row = extra_height / non_collapsed_rows as f32;

                    for row_idx in cell_info.row..end_row {
                        if !table_ctx.collapsed_rows.contains(&row_idx) {
                            table_ctx.row_heights[row_idx] += per_row;
                        }
                    }
                }
            }
        }
    }

    // CSS 2.2 Section 17.6: Final pass - ensure collapsed rows have height 0
    for &row_idx in &table_ctx.collapsed_rows {
        if row_idx < table_ctx.row_heights.len() {
            table_ctx.row_heights[row_idx] = 0.0;
        }
    }

    Ok(())
}

/// Position all cells in the table grid with calculated widths and heights
fn position_table_cells<T: ParsedFontTrait>(
    table_ctx: &mut TableLayoutContext,
    tree: &mut LayoutTree,
    ctx: &mut LayoutContext<'_, T>,
    table_index: usize,
    constraints: &LayoutConstraints,
) -> Result<BTreeMap<usize, LogicalPosition>> {
    debug_log!(ctx, "Positioning table cells in grid");

    let mut positions = BTreeMap::new();

    // Get border spacing values if border-collapse is separate
    let (h_spacing, v_spacing) = if table_ctx.border_collapse == StyleBorderCollapse::Separate {
        let styled_dom = ctx.styled_dom;
        let table_id = tree.nodes[table_index].dom_node_id.unwrap();
        let table_state = &styled_dom.styled_nodes.as_container()[table_id].styled_node_state;

        let spacing_context = ResolutionContext {
            element_font_size: get_element_font_size(styled_dom, table_id, table_state),
            parent_font_size: get_parent_font_size(styled_dom, table_id, table_state),
            root_font_size: get_root_font_size(styled_dom, table_state),
            containing_block_size: PhysicalSize::new(0.0, 0.0),
            element_size: None,
            viewport_size: PhysicalSize::new(0.0, 0.0), // TODO: Get actual DPI scale from ctx
        };

        let h = table_ctx
            .border_spacing
            .horizontal
            .resolve_with_context(&spacing_context, PropertyContext::Other);

        let v = table_ctx
            .border_spacing
            .vertical
            .resolve_with_context(&spacing_context, PropertyContext::Other);

        (h, v)
    } else {
        (0.0, 0.0)
    };

    debug_log!(
        ctx,
        "Border spacing: h={:.2}, v={:.2}",
        h_spacing,
        v_spacing
    );

    // Calculate cumulative column positions (x-offsets) with spacing
    let mut col_positions = vec![0.0; table_ctx.columns.len()];
    let mut x_offset = h_spacing; // Start with spacing on the left
    for (i, col) in table_ctx.columns.iter().enumerate() {
        col_positions[i] = x_offset;
        if let Some(width) = col.computed_width {
            x_offset += width + h_spacing; // Add spacing between columns
        }
    }

    // Calculate cumulative row positions (y-offsets) with spacing
    let mut row_positions = vec![0.0; table_ctx.num_rows];
    let mut y_offset = v_spacing; // Start with spacing on the top
    for (i, &height) in table_ctx.row_heights.iter().enumerate() {
        row_positions[i] = y_offset;
        y_offset += height + v_spacing; // Add spacing between rows
    }

    // Position each cell
    for cell_info in &table_ctx.cells {
        let cell_node = tree
            .get_mut(cell_info.node_index)
            .ok_or(LayoutError::InvalidTree)?;

        // Calculate cell position
        let x = col_positions.get(cell_info.column).copied().unwrap_or(0.0);
        let y = row_positions.get(cell_info.row).copied().unwrap_or(0.0);

        // Calculate cell size (sum of spanned columns/rows)
        let mut width = 0.0;
        debug_info!(
            ctx,
            "[position_table_cells] Cell {}: calculating width from cols {}..{}",
            cell_info.node_index,
            cell_info.column,
            cell_info.column + cell_info.colspan
        );
        for col_idx in cell_info.column..(cell_info.column + cell_info.colspan) {
            if let Some(col) = table_ctx.columns.get(col_idx) {
                debug_info!(
                    ctx,
                    "[position_table_cells]   Col {}: computed_width={:?}",
                    col_idx,
                    col.computed_width
                );
                if let Some(col_width) = col.computed_width {
                    width += col_width;
                    // Add spacing between spanned columns (but not after the last one)
                    if col_idx < cell_info.column + cell_info.colspan - 1 {
                        width += h_spacing;
                    }
                } else {
                    debug_info!(
                        ctx,
                        "[position_table_cells]   WARN:  Col {} has NO computed_width!",
                        col_idx
                    );
                }
            } else {
                debug_info!(
                    ctx,
                    "[position_table_cells]   WARN:  Col {} not found in table_ctx.columns!",
                    col_idx
                );
            }
        }

        let mut height = 0.0;
        let end_row = cell_info.row + cell_info.rowspan;
        for row_idx in cell_info.row..end_row {
            if let Some(&row_height) = table_ctx.row_heights.get(row_idx) {
                height += row_height;
                // Add spacing between spanned rows (but not after the last one)
                if row_idx < end_row - 1 {
                    height += v_spacing;
                }
            }
        }

        // Update cell's used size and position
        let writing_mode = constraints.writing_mode;
        // Table layout works in main/cross axes, must convert back to logical width/height

        debug_info!(
            ctx,
            "[position_table_cells] Cell {}: BEFORE from_main_cross: width={}, height={}, \
             writing_mode={:?}",
            cell_info.node_index,
            width,
            height,
            writing_mode
        );

        cell_node.used_size = Some(LogicalSize::from_main_cross(height, width, writing_mode));

        debug_info!(
            ctx,
            "[position_table_cells] Cell {}: AFTER from_main_cross: used_size={:?}",
            cell_info.node_index,
            cell_node.used_size
        );

        debug_info!(
            ctx,
            "[position_table_cells] Cell {}: setting used_size to {}x{} (row_heights={:?})",
            cell_info.node_index,
            width,
            height,
            table_ctx.row_heights
        );

        // Apply vertical-align to cell content if it has inline layout
        if let Some(ref cached_layout) = cell_node.inline_layout_result {
            let inline_result = &cached_layout.layout;
            use StyleVerticalAlign;

            // Get vertical-align property from styled_dom
            let vertical_align = if let Some(dom_id) = cell_node.dom_node_id {
                let node_data = &ctx.styled_dom.node_data.as_container()[dom_id];
                let node_state = StyledNodeState::default();

                ctx.styled_dom
                    .css_property_cache
                    .ptr
                    .get_vertical_align(node_data, &dom_id, &node_state)
                    .and_then(|v| v.get_property().copied())
                    .unwrap_or(StyleVerticalAlign::Top)
            } else {
                StyleVerticalAlign::Top
            };

            // Calculate content height from inline layout bounds
            let content_bounds = inline_result.bounds();
            let content_height = content_bounds.height;

            // Get padding and border to calculate content-box height
            // height is border-box, but vertical alignment should be within content-box
            let padding = &cell_node.box_props.padding;
            let border = &cell_node.box_props.border;
            let content_box_height = height
                - padding.main_start(writing_mode)
                - padding.main_end(writing_mode)
                - border.main_start(writing_mode)
                - border.main_end(writing_mode);

            // Calculate vertical offset based on alignment within content-box
            let align_factor = match vertical_align {
                StyleVerticalAlign::Top => 0.0,
                StyleVerticalAlign::Middle => 0.5,
                StyleVerticalAlign::Bottom => 1.0,
                // For inline text alignments within table cells, default to middle
                StyleVerticalAlign::Baseline
                | StyleVerticalAlign::Sub
                | StyleVerticalAlign::Superscript
                | StyleVerticalAlign::TextTop
                | StyleVerticalAlign::TextBottom => 0.5,
            };
            let y_offset = (content_box_height - content_height) * align_factor;

            debug_info!(
                ctx,
                "[position_table_cells] Cell {}: vertical-align={:?}, border_box_height={}, \
                 content_box_height={}, content_height={}, y_offset={}",
                cell_info.node_index,
                vertical_align,
                height,
                content_box_height,
                content_height,
                y_offset
            );

            // Create new layout with adjusted positions
            if y_offset.abs() > 0.01 {
                // Only adjust if offset is significant
                use std::sync::Arc;

                use crate::text3::cache::{PositionedItem, UnifiedLayout};

                let adjusted_items: Vec<PositionedItem> = inline_result
                    .items
                    .iter()
                    .map(|item| PositionedItem {
                        item: item.item.clone(),
                        position: crate::text3::cache::Point {
                            x: item.position.x,
                            y: item.position.y + y_offset,
                        },
                        line_index: item.line_index,
                    })
                    .collect();

                let adjusted_layout = UnifiedLayout {
                    items: adjusted_items,
                    overflow: inline_result.overflow.clone(),
                };

                // Keep the same constraint type from the cached layout
                cell_node.inline_layout_result = Some(CachedInlineLayout::new(
                    Arc::new(adjusted_layout),
                    cached_layout.available_width,
                    cached_layout.has_floats,
                ));
            }
        }

        // Store position relative to table origin
        let position = LogicalPosition::from_main_cross(y, x, writing_mode);

        // Insert position into map so cache module can position the cell
        positions.insert(cell_info.node_index, position);

        debug_log!(
            ctx,
            "Cell at row={}, col={}: pos=({:.2}, {:.2}), size=({:.2}x{:.2})",
            cell_info.row,
            cell_info.column,
            x,
            y,
            width,
            height
        );
    }

    Ok(positions)
}

/// Gathers all inline content for `text3`, recursively laying out `inline-block` children
/// to determine their size and baseline before passing them to the text engine.
///
/// This function also assigns IFC membership to all participating nodes:
/// - The IFC root gets an `ifc_id` assigned
/// - Each text/inline child gets `ifc_membership` set with a reference back to the IFC root
///
/// This mapping enables efficient cursor hit-testing: when a text node is clicked,
/// we can find its parent IFC's `inline_layout_result` via `ifc_membership.ifc_root_layout_index`.
fn collect_and_measure_inline_content<T: ParsedFontTrait>(
    ctx: &mut LayoutContext<'_, T>,
    text_cache: &mut TextLayoutCache,
    tree: &mut LayoutTree,
    ifc_root_index: usize,
    constraints: &LayoutConstraints,
) -> Result<(Vec<InlineContent>, HashMap<ContentIndex, usize>)> {
    use crate::solver3::layout_tree::{IfcId, IfcMembership};

    debug_ifc_layout!(
        ctx,
        "collect_and_measure_inline_content: node_index={}",
        ifc_root_index
    );

    // Generate a unique IFC ID for this inline formatting context
    let ifc_id = IfcId::unique();

    // Store IFC ID on the IFC root node
    if let Some(ifc_root_node) = tree.get_mut(ifc_root_index) {
        ifc_root_node.ifc_id = Some(ifc_id);
    }

    let mut content = Vec::new();
    // Maps the `ContentIndex` used by text3 back to the `LayoutNode` index.
    let mut child_map = HashMap::new();
    // Track the current run index for IFC membership assignment
    let mut current_run_index: u32 = 0;

    let ifc_root_node = tree.get(ifc_root_index).ok_or(LayoutError::InvalidTree)?;

    // Check if this is an anonymous IFC wrapper (has no DOM ID)
    let is_anonymous = ifc_root_node.dom_node_id.is_none();

    // Get the DOM node ID of the IFC root, or find it from parent/children for anonymous boxes
    // CSS 2.2 § 9.2.1.1: Anonymous boxes inherit properties from their enclosing box
    let ifc_root_dom_id = match ifc_root_node.dom_node_id {
        Some(id) => id,
        None => {
            // Anonymous box - get DOM ID from parent or first child with DOM ID
            let parent_dom_id = ifc_root_node
                .parent
                .and_then(|p| tree.get(p))
                .and_then(|n| n.dom_node_id);

            if let Some(id) = parent_dom_id {
                id
            } else {
                // Try to find DOM ID from first child
                match ifc_root_node
                    .children
                    .iter()
                    .filter_map(|&child_idx| tree.get(child_idx))
                    .filter_map(|n| n.dom_node_id)
                    .next()
                {
                    Some(id) => id,
                    None => {
                        debug_warning!(ctx, "IFC root and all ancestors/children have no DOM ID");
                        return Ok((content, child_map));
                    }
                }
            }
        }
    };

    // Collect children to avoid holding an immutable borrow during iteration
    let children: Vec<_> = ifc_root_node.children.clone();
    drop(ifc_root_node);

    debug_ifc_layout!(
        ctx,
        "Node {} has {} layout children, is_anonymous={}",
        ifc_root_index,
        children.len(),
        is_anonymous
    );

    // For anonymous IFC wrappers, we collect content from layout tree children
    // For regular IFC roots, we also check DOM children for text nodes
    if is_anonymous {
        // Anonymous IFC wrapper - iterate over layout tree children and collect their content
        for (item_idx, &child_index) in children.iter().enumerate() {
            let content_index = ContentIndex {
                run_index: ifc_root_index as u32,
                item_index: item_idx as u32,
            };

            let child_node = tree.get(child_index).ok_or(LayoutError::InvalidTree)?;
            let Some(dom_id) = child_node.dom_node_id else {
                debug_warning!(
                    ctx,
                    "Anonymous IFC child at index {} has no DOM ID",
                    child_index
                );
                continue;
            };

            let node_data = &ctx.styled_dom.node_data.as_container()[dom_id];

            // Check if this is a text node
            if let NodeType::Text(ref text_content) = node_data.get_node_type() {
                debug_info!(
                    ctx,
                    "[collect_and_measure_inline_content] OK: Found text node (DOM {:?}) in anonymous wrapper: '{}'",
                    dom_id,
                    text_content.as_str()
                );
                // Get style from the TEXT NODE itself (dom_id), not the IFC root
                // This ensures inline styles like color: #666666 are applied to the text
                // Uses split_text_for_whitespace to correctly handle white-space: pre with \n
                let style = Arc::new(get_style_properties(ctx.styled_dom, dom_id));
                let text_items = split_text_for_whitespace(
                    ctx.styled_dom,
                    dom_id,
                    text_content.as_str(),
                    style,
                );
                content.extend(text_items);
                child_map.insert(content_index, child_index);
                
                // Set IFC membership on the text node - drop child_node borrow first
                drop(child_node);
                if let Some(child_node_mut) = tree.get_mut(child_index) {
                    child_node_mut.ifc_membership = Some(IfcMembership {
                        ifc_id,
                        ifc_root_layout_index: ifc_root_index,
                        run_index: current_run_index,
                    });
                }
                current_run_index += 1;
                
                continue;
            }

            // Non-text inline child - add as shape for inline-block
            let display = get_display_property(ctx.styled_dom, Some(dom_id)).unwrap_or_default();
            if display != LayoutDisplay::Inline {
                // This is an atomic inline-level box (e.g., inline-block, image).
                // We must determine its size and baseline before passing it to text3.

                // The intrinsic sizing pass has already calculated its preferred size.
                let intrinsic_size = child_node.intrinsic_sizes.clone().unwrap_or_default();
                let box_props = child_node.box_props.clone();

                let styled_node_state = ctx
                    .styled_dom
                    .styled_nodes
                    .as_container()
                    .get(dom_id)
                    .map(|n| n.styled_node_state.clone())
                    .unwrap_or_default();

                // Calculate tentative border-box size based on CSS properties
                let tentative_size = crate::solver3::sizing::calculate_used_size_for_node(
                    ctx.styled_dom,
                    Some(dom_id),
                    constraints.containing_block_size,
                    intrinsic_size,
                    &box_props,
                )?;

                let writing_mode = get_writing_mode(ctx.styled_dom, dom_id, &styled_node_state)
                    .unwrap_or_default();

                // Determine content-box size for laying out children
                let content_box_size = box_props.inner_size(tentative_size, writing_mode);

                // To find its height and baseline, we must lay out its contents.
                let child_constraints = LayoutConstraints {
                    available_size: LogicalSize::new(content_box_size.width, f32::INFINITY),
                    writing_mode,
                    bfc_state: None,
                    text_align: TextAlign::Start,
                    containing_block_size: constraints.containing_block_size,
                    available_width_type: Text3AvailableSpace::Definite(content_box_size.width),
                };

                // Drop the immutable borrow before calling layout_formatting_context
                drop(child_node);

                // Recursively lay out the inline-block to get its final height and baseline.
                let mut empty_float_cache = std::collections::BTreeMap::new();
                let layout_result = layout_formatting_context(
                    ctx,
                    tree,
                    text_cache,
                    child_index,
                    &child_constraints,
                    &mut empty_float_cache,
                )?;

                let css_height = get_css_height(ctx.styled_dom, dom_id, &styled_node_state);

                // Determine final border-box height
                let final_height = match css_height.unwrap_or_default() {
                    LayoutHeight::Auto => {
                        let content_height = layout_result.output.overflow_size.height;
                        content_height
                            + box_props.padding.main_sum(writing_mode)
                            + box_props.border.main_sum(writing_mode)
                    }
                    _ => tentative_size.height,
                };

                let final_size = LogicalSize::new(tentative_size.width, final_height);

                // Update the node in the tree with its now-known used size.
                tree.get_mut(child_index).unwrap().used_size = Some(final_size);

                let baseline_offset = layout_result.output.baseline.unwrap_or(final_height);

                // Get margins for inline-block positioning in the inline flow
                // The margin-box size is used so text3 positions inline-blocks with proper spacing
                let margin = &box_props.margin;
                let margin_box_width = final_size.width + margin.left + margin.right;
                let margin_box_height = final_size.height + margin.top + margin.bottom;

                // For inline-block shapes, text3 uses the content array index as run_index
                // and always item_index=0 for objects. We must match this when inserting into child_map.
                let shape_content_index = ContentIndex {
                    run_index: content.len() as u32,
                    item_index: 0,
                };
                content.push(InlineContent::Shape(InlineShape {
                    shape_def: ShapeDefinition::Rectangle {
                        size: crate::text3::cache::Size {
                            // Use margin-box size for positioning in inline flow
                            width: margin_box_width,
                            height: margin_box_height,
                        },
                        corner_radius: None,
                    },
                    fill: None,
                    stroke: None,
                    // Adjust baseline offset by top margin
                    baseline_offset: baseline_offset + margin.top,
                    source_node_id: Some(dom_id),
                }));
                child_map.insert(shape_content_index, child_index);
            } else {
                // Regular inline element - collect its text children
                let span_style = get_style_properties(ctx.styled_dom, dom_id);
                collect_inline_span_recursive(
                    ctx,
                    tree,
                    dom_id,
                    span_style,
                    &mut content,
                    &mut child_map,
                    &children,
                    constraints,
                )?;
            }
        }

        return Ok((content, child_map));
    }

    // Regular (non-anonymous) IFC root - check for list markers and use DOM traversal

    // Check if this IFC root OR its parent is a list-item and needs a marker
    // Case 1: IFC root itself is list-item (e.g., <li> with display: list-item)
    // Case 2: IFC root's parent is list-item (e.g., <li><text>...</text></li>)
    let ifc_root_node = tree.get(ifc_root_index).ok_or(LayoutError::InvalidTree)?;
    let mut list_item_dom_id: Option<NodeId> = None;

    // Check IFC root itself
    if let Some(dom_id) = ifc_root_node.dom_node_id {
        let node_data = &ctx.styled_dom.node_data.as_container()[dom_id];
        let node_state = StyledNodeState::default();

        if let Some(display_value) =
            ctx.styled_dom
                .css_property_cache
                .ptr
                .get_display(node_data, &dom_id, &node_state)
        {
            if let Some(display) = display_value.get_property() {
                use LayoutDisplay;
                if *display == LayoutDisplay::ListItem {
                    debug_ifc_layout!(ctx, "IFC root NodeId({:?}) is list-item", dom_id);
                    list_item_dom_id = Some(dom_id);
                }
            }
        }
    }

    // Check IFC root's parent
    if list_item_dom_id.is_none() {
        if let Some(parent_idx) = ifc_root_node.parent {
            if let Some(parent_node) = tree.get(parent_idx) {
                if let Some(parent_dom_id) = parent_node.dom_node_id {
                    let parent_node_data = &ctx.styled_dom.node_data.as_container()[parent_dom_id];
                    let parent_node_state = StyledNodeState::default();

                    if let Some(display_value) = ctx.styled_dom.css_property_cache.ptr.get_display(
                        parent_node_data,
                        &parent_dom_id,
                        &parent_node_state,
                    ) {
                        if let Some(display) = display_value.get_property() {
                            use LayoutDisplay;
                            if *display == LayoutDisplay::ListItem {
                                debug_ifc_layout!(
                                    ctx,
                                    "IFC root parent NodeId({:?}) is list-item",
                                    parent_dom_id
                                );
                                list_item_dom_id = Some(parent_dom_id);
                            }
                        }
                    }
                }
            }
        }
    }

    // If we found a list-item, generate markers
    if let Some(list_dom_id) = list_item_dom_id {
        debug_ifc_layout!(
            ctx,
            "Found list-item (NodeId({:?})), generating marker",
            list_dom_id
        );

        // Find the layout node index for the list-item DOM node
        let list_item_layout_idx = tree
            .nodes
            .iter()
            .enumerate()
            .find(|(_, node)| {
                node.dom_node_id == Some(list_dom_id) && node.pseudo_element.is_none()
            })
            .map(|(idx, _)| idx);

        if let Some(list_idx) = list_item_layout_idx {
            // Per CSS spec, the ::marker pseudo-element is the first child of the list-item
            // Find the ::marker pseudo-element in the list-item's children
            let list_item_node = tree.get(list_idx).ok_or(LayoutError::InvalidTree)?;
            let marker_idx = list_item_node
                .children
                .iter()
                .find(|&&child_idx| {
                    tree.get(child_idx)
                        .map(|child| child.pseudo_element == Some(PseudoElement::Marker))
                        .unwrap_or(false)
                })
                .copied();

            if let Some(marker_idx) = marker_idx {
                debug_ifc_layout!(ctx, "Found ::marker pseudo-element at index {}", marker_idx);

                // Get the DOM ID for style resolution (marker references the same DOM node as
                // list-item)
                let list_dom_id_for_style = tree
                    .get(marker_idx)
                    .and_then(|n| n.dom_node_id)
                    .unwrap_or(list_dom_id);

                // Get list-style-position to determine marker positioning
                // Default is 'outside' per CSS Lists Module Level 3

                let list_style_position =
                    get_list_style_position(ctx.styled_dom, Some(list_dom_id));
                let position_outside =
                    matches!(list_style_position, StyleListStylePosition::Outside);

                debug_ifc_layout!(
                    ctx,
                    "List marker list-style-position: {:?} (outside={})",
                    list_style_position,
                    position_outside
                );

                // Generate marker text segments - font fallback happens during shaping
                let base_style =
                    Arc::new(get_style_properties(ctx.styled_dom, list_dom_id_for_style));
                let marker_segments = generate_list_marker_segments(
                    tree,
                    ctx.styled_dom,
                    marker_idx, // Pass the marker index, not the list-item index
                    ctx.counters,
                    base_style,
                    ctx.debug_messages,
                );

                debug_ifc_layout!(
                    ctx,
                    "Generated {} list marker segments",
                    marker_segments.len()
                );

                // Add markers as InlineContent::Marker with position information
                // Outside markers will be positioned in the padding gutter by the layout engine
                for segment in marker_segments {
                    content.push(InlineContent::Marker {
                        run: segment,
                        position_outside,
                    });
                }
            } else {
                debug_ifc_layout!(
                    ctx,
                    "WARNING: List-item at index {} has no ::marker pseudo-element",
                    list_idx
                );
            }
        }
    }

    drop(ifc_root_node);

    // IMPORTANT: We need to traverse the DOM, not just the layout tree!
    //
    // According to CSS spec, a block container with inline-level children establishes
    // an IFC and should collect ALL inline content, including text nodes.
    // Text nodes exist in the DOM but might not have their own layout tree nodes.

    // Debug: Check what the node_hierarchy says about this node
    let node_hier_item = &ctx.styled_dom.node_hierarchy.as_container()[ifc_root_dom_id];
    debug_info!(
        ctx,
        "[collect_and_measure_inline_content] DEBUG: node_hier_item.first_child={:?}, \
         last_child={:?}",
        node_hier_item.first_child_id(ifc_root_dom_id),
        node_hier_item.last_child_id()
    );

    let dom_children: Vec<NodeId> = ifc_root_dom_id
        .az_children(&ctx.styled_dom.node_hierarchy.as_container())
        .collect();

    let ifc_root_node_data = &ctx.styled_dom.node_data.as_container()[ifc_root_dom_id];

    // SPECIAL CASE: If the IFC root itself is a text node (leaf node),
    // add its text content directly instead of iterating over children
    // Uses split_text_for_whitespace to correctly handle white-space: pre with \n
    if let NodeType::Text(ref text_content) = ifc_root_node_data.get_node_type() {
        let style = Arc::new(get_style_properties(ctx.styled_dom, ifc_root_dom_id));
        let text_items = split_text_for_whitespace(
            ctx.styled_dom,
            ifc_root_dom_id,
            text_content.as_str(),
            style,
        );
        content.extend(text_items);
        return Ok((content, child_map));
    }

    let ifc_root_node_type = match ifc_root_node_data.get_node_type() {
        NodeType::Div => "Div",
        NodeType::Text(_) => "Text",
        NodeType::Body => "Body",
        _ => "Other",
    };

    debug_info!(
        ctx,
        "[collect_and_measure_inline_content] IFC root has {} DOM children",
        dom_children.len()
    );

    for (item_idx, &dom_child_id) in dom_children.iter().enumerate() {
        let content_index = ContentIndex {
            run_index: ifc_root_index as u32,
            item_index: item_idx as u32,
        };

        let node_data = &ctx.styled_dom.node_data.as_container()[dom_child_id];

        // Check if this is a text node
        if let NodeType::Text(ref text_content) = node_data.get_node_type() {
            debug_info!(
                ctx,
                "[collect_and_measure_inline_content] OK: Found text node (DOM child {:?}): '{}'",
                dom_child_id,
                text_content.as_str()
            );
            
            // Get style from the TEXT NODE itself (dom_child_id), not the IFC root
            // This ensures inline styles like color: #666666 are applied to the text
            // Uses split_text_for_whitespace to correctly handle white-space: pre with \n
            let style = Arc::new(get_style_properties(ctx.styled_dom, dom_child_id));
            let text_items = split_text_for_whitespace(
                ctx.styled_dom,
                dom_child_id,
                text_content.as_str(),
                style,
            );
            content.extend(text_items);
            
            // Set IFC membership on the text node's layout node (if it exists)
            // Text nodes may or may not have their own layout tree entry depending on
            // whether they're wrapped in an anonymous IFC wrapper
            if let Some(&layout_idx) = tree.dom_to_layout.get(&dom_child_id).and_then(|v| v.first()) {
                if let Some(text_layout_node) = tree.get_mut(layout_idx) {
                    text_layout_node.ifc_membership = Some(IfcMembership {
                        ifc_id,
                        ifc_root_layout_index: ifc_root_index,
                        run_index: current_run_index,
                    });
                }
            }
            current_run_index += 1;
            
            continue;
        }

        // For non-text nodes, find their corresponding layout tree node
        let child_index = children
            .iter()
            .find(|&&idx| {
                tree.get(idx)
                    .and_then(|n| n.dom_node_id)
                    .map(|id| id == dom_child_id)
                    .unwrap_or(false)
            })
            .copied();

        let Some(child_index) = child_index else {
            debug_info!(
                ctx,
                "[collect_and_measure_inline_content] WARN: DOM child {:?} has no layout node",
                dom_child_id
            );
            continue;
        };

        let child_node = tree.get(child_index).ok_or(LayoutError::InvalidTree)?;
        // At this point we have a non-text DOM child with a layout node
        let dom_id = child_node.dom_node_id.unwrap();

        let display = get_display_property(ctx.styled_dom, Some(dom_id)).unwrap_or_default();

        if display != LayoutDisplay::Inline {
            // This is an atomic inline-level box (e.g., inline-block, image).
            // We must determine its size and baseline before passing it to text3.

            // The intrinsic sizing pass has already calculated its preferred size.
            let intrinsic_size = child_node.intrinsic_sizes.clone().unwrap_or_default();
            let box_props = child_node.box_props.clone();

            let styled_node_state = ctx
                .styled_dom
                .styled_nodes
                .as_container()
                .get(dom_id)
                .map(|n| n.styled_node_state.clone())
                .unwrap_or_default();

            // Calculate tentative border-box size based on CSS properties
            // This correctly handles explicit width/height, box-sizing, and constraints
            let tentative_size = crate::solver3::sizing::calculate_used_size_for_node(
                ctx.styled_dom,
                Some(dom_id),
                constraints.containing_block_size,
                intrinsic_size,
                &box_props,
            )?;

            let writing_mode =
                get_writing_mode(ctx.styled_dom, dom_id, &styled_node_state).unwrap_or_default();

            // Determine content-box size for laying out children
            let content_box_size = box_props.inner_size(tentative_size, writing_mode);

            debug_info!(
                ctx,
                "[collect_and_measure_inline_content] Inline-block NodeId({:?}): \
                 tentative_border_box={:?}, content_box={:?}",
                dom_id,
                tentative_size,
                content_box_size
            );

            // To find its height and baseline, we must lay out its contents.
            let child_constraints = LayoutConstraints {
                available_size: LogicalSize::new(content_box_size.width, f32::INFINITY),
                writing_mode,
                // Inline-blocks establish a new BFC, so no state is passed in.
                bfc_state: None,
                // Does not affect size/baseline of the container.
                text_align: TextAlign::Start,
                containing_block_size: constraints.containing_block_size,
                available_width_type: Text3AvailableSpace::Definite(content_box_size.width),
            };

            // Drop the immutable borrow before calling layout_formatting_context
            drop(child_node);

            // Recursively lay out the inline-block to get its final height and baseline.
            // Note: This does not affect its final position, only its dimensions.
            let mut empty_float_cache = std::collections::BTreeMap::new();
            let layout_result = layout_formatting_context(
                ctx,
                tree,
                text_cache,
                child_index,
                &child_constraints,
                &mut empty_float_cache,
            )?;

            let css_height = get_css_height(ctx.styled_dom, dom_id, &styled_node_state);

            // Determine final border-box height
            let final_height = match css_height.unwrap_or_default() {
                LayoutHeight::Auto => {
                    // For auto height, add padding and border to the content height
                    let content_height = layout_result.output.overflow_size.height;
                    content_height
                        + box_props.padding.main_sum(writing_mode)
                        + box_props.border.main_sum(writing_mode)
                }
                // For explicit height, calculate_used_size_for_node already gave us the correct border-box height
                _ => tentative_size.height,
            };

            debug_info!(
                ctx,
                "[collect_and_measure_inline_content] Inline-block NodeId({:?}): \
                 layout_content_height={}, css_height={:?}, final_border_box_height={}",
                dom_id,
                layout_result.output.overflow_size.height,
                css_height,
                final_height
            );

            let final_size = LogicalSize::new(tentative_size.width, final_height);

            // Update the node in the tree with its now-known used size.
            tree.get_mut(child_index).unwrap().used_size = Some(final_size);

            // CSS 2.2 § 10.8.1: For inline-block elements, the baseline is the baseline of the
            // last line box in the normal flow, unless it has no in-flow line boxes, in which
            // case the baseline is the bottom margin edge.
            //
            // `layout_result.output.baseline` returns the Y-position of the baseline measured
            // from the TOP of the content box. But `get_item_vertical_metrics` expects
            // `baseline_offset` to be the distance from the BOTTOM to the baseline.
            //
            // Conversion: baseline_offset_from_bottom = height - baseline_from_top
            //
            // If no baseline is found (e.g., the inline-block has no text), we fall back to
            // the bottom margin edge (baseline_offset = 0, meaning baseline at bottom).
            let baseline_from_top = layout_result.output.baseline;
            let baseline_offset = match baseline_from_top {
                Some(baseline_y) => {
                    // baseline_y is measured from top of content box
                    // We need to add padding and border to get the position within the border-box
                    let content_box_top = box_props.padding.top + box_props.border.top;
                    let baseline_from_border_box_top = baseline_y + content_box_top;
                    // Convert to distance from bottom
                    (final_height - baseline_from_border_box_top).max(0.0)
                }
                None => {
                    // No baseline found - use bottom margin edge (baseline at bottom)
                    0.0
                }
            };
            
            debug_info!(
                ctx,
                "[collect_and_measure_inline_content] Inline-block NodeId({:?}): \
                 baseline_from_top={:?}, final_height={}, baseline_offset_from_bottom={}",
                dom_id,
                baseline_from_top,
                final_height,
                baseline_offset
            );

            // Get margins for inline-block positioning
            // For inline-blocks, we need to include margins in the shape size
            // so that text3 positions them correctly with spacing
            let margin = &box_props.margin;
            let margin_box_width = final_size.width + margin.left + margin.right;
            let margin_box_height = final_size.height + margin.top + margin.bottom;

            // For inline-block shapes, text3 uses the content array index as run_index
            // and always item_index=0 for objects. We must match this when inserting into child_map.
            let shape_content_index = ContentIndex {
                run_index: content.len() as u32,
                item_index: 0,
            };
            content.push(InlineContent::Shape(InlineShape {
                shape_def: ShapeDefinition::Rectangle {
                    size: crate::text3::cache::Size {
                        // Use margin-box size for positioning in inline flow
                        width: margin_box_width,
                        height: margin_box_height,
                    },
                    corner_radius: None,
                },
                fill: None,
                stroke: None,
                // Adjust baseline offset by top margin
                baseline_offset: baseline_offset + margin.top,
                source_node_id: Some(dom_id),
            }));
            child_map.insert(shape_content_index, child_index);
        } else if let NodeType::Image(image_ref) =
            ctx.styled_dom.node_data.as_container()[dom_id].get_node_type()
        {
            // Images are replaced elements - they have intrinsic dimensions
            // and CSS width/height can constrain them
            
            // Re-get child_node since we dropped it earlier for the inline-block case
            let child_node = tree.get(child_index).ok_or(LayoutError::InvalidTree)?;
            let box_props = child_node.box_props.clone();

            // Get intrinsic size from the image data or fall back to layout node
            let intrinsic_size = child_node
                .intrinsic_sizes
                .clone()
                .unwrap_or(IntrinsicSizes {
                    max_content_width: 50.0,
                    max_content_height: 50.0,
                    ..Default::default()
                });
            
            // Get styled node state for CSS property lookup
            let styled_node_state = ctx
                .styled_dom
                .styled_nodes
                .as_container()
                .get(dom_id)
                .map(|n| n.styled_node_state.clone())
                .unwrap_or_default();
            
            // Calculate the used size respecting CSS width/height constraints
            let tentative_size = crate::solver3::sizing::calculate_used_size_for_node(
                ctx.styled_dom,
                Some(dom_id),
                constraints.containing_block_size,
                intrinsic_size.clone(),
                &box_props,
            )?;
            
            // Drop immutable borrow before mutable access
            drop(child_node);
            
            // Set the used_size on the layout node so paint_rect works correctly
            let final_size = LogicalSize::new(tentative_size.width, tentative_size.height);
            tree.get_mut(child_index).unwrap().used_size = Some(final_size);
            
            println!("[FC IMAGE] Image node {} final_size: {}x{}", 
                child_index, final_size.width, final_size.height);
            
            // Calculate display size for text3 (this is what text3 uses for positioning)
            let display_width = if final_size.width > 0.0 { 
                Some(final_size.width) 
            } else { 
                None 
            };
            let display_height = if final_size.height > 0.0 { 
                Some(final_size.height) 
            } else { 
                None 
            };
            
            content.push(InlineContent::Image(InlineImage {
                source: ImageSource::Ref(image_ref.clone()),
                intrinsic_size: crate::text3::cache::Size {
                    width: intrinsic_size.max_content_width,
                    height: intrinsic_size.max_content_height,
                },
                display_size: if display_width.is_some() || display_height.is_some() {
                    Some(crate::text3::cache::Size {
                        width: display_width.unwrap_or(intrinsic_size.max_content_width),
                        height: display_height.unwrap_or(intrinsic_size.max_content_height),
                    })
                } else {
                    None
                },
                // Images are bottom-aligned with the baseline by default
                baseline_offset: 0.0,
                alignment: crate::text3::cache::VerticalAlign::Baseline,
                object_fit: ObjectFit::Fill,
            }));
            // For images, text3 uses the content array index as run_index
            // and always item_index=0 for objects. We must match this.
            let image_content_index = ContentIndex {
                run_index: (content.len() - 1) as u32,  // -1 because we just pushed
                item_index: 0,
            };
            child_map.insert(image_content_index, child_index);
        } else {
            // This is a regular inline box (display: inline) - e.g., <span>, <em>, <strong>
            //
            // According to CSS Inline-3 spec §2, inline boxes are "transparent" wrappers
            // We must recursively collect their text children with inherited style
            debug_info!(
                ctx,
                "[collect_and_measure_inline_content] Found inline span (DOM {:?}), recursing",
                dom_id
            );

            let span_style = get_style_properties(ctx.styled_dom, dom_id);
            collect_inline_span_recursive(
                ctx,
                tree,
                dom_id,
                span_style,
                &mut content,
                &mut child_map,
                &children,
                constraints,
            )?;
        }
    }
    Ok((content, child_map))
}

/// Recursively collects inline content from an inline span (display: inline) element.
///
/// According to CSS Inline Layout Module Level 3 §2:
///
/// "Inline boxes are transparent wrappers that wrap their content."
///
/// They don't create a new formatting context - their children participate in the
/// same IFC as the parent. This function processes:
///
/// - Text nodes: collected with the span's inherited style
/// - Nested inline spans: recursively descended
/// - Inline-blocks, images: measured and added as shapes
fn collect_inline_span_recursive<T: ParsedFontTrait>(
    ctx: &mut LayoutContext<'_, T>,
    tree: &mut LayoutTree,
    span_dom_id: NodeId,
    span_style: StyleProperties,
    content: &mut Vec<InlineContent>,
    child_map: &mut HashMap<ContentIndex, usize>,
    parent_children: &[usize], // Layout tree children of parent IFC
    constraints: &LayoutConstraints,
) -> Result<()> {
    debug_info!(
        ctx,
        "[collect_inline_span_recursive] Processing inline span {:?}",
        span_dom_id
    );

    // Get DOM children of this span
    let span_dom_children: Vec<NodeId> = span_dom_id
        .az_children(&ctx.styled_dom.node_hierarchy.as_container())
        .collect();

    debug_info!(
        ctx,
        "[collect_inline_span_recursive] Span has {} DOM children",
        span_dom_children.len()
    );

    for &child_dom_id in &span_dom_children {
        let node_data = &ctx.styled_dom.node_data.as_container()[child_dom_id];

        // CASE 1: Text node - collect with span's style
        if let NodeType::Text(ref text_content) = node_data.get_node_type() {
            debug_info!(
                ctx,
                "[collect_inline_span_recursive] ✓ Found text in span: '{}'",
                text_content.as_str()
            );
            content.push(InlineContent::Text(StyledRun {
                text: text_content.to_string(),
                style: Arc::new(span_style.clone()),
                logical_start_byte: 0,
                source_node_id: Some(child_dom_id),
            }));
            continue;
        }

        // CASE 2: Element node - check its display type
        let child_display =
            get_display_property(ctx.styled_dom, Some(child_dom_id)).unwrap_or_default();

        // Find the corresponding layout tree node
        let child_index = parent_children
            .iter()
            .find(|&&idx| {
                tree.get(idx)
                    .and_then(|n| n.dom_node_id)
                    .map(|id| id == child_dom_id)
                    .unwrap_or(false)
            })
            .copied();

        match child_display {
            LayoutDisplay::Inline => {
                // Nested inline span - recurse with child's style
                debug_info!(
                    ctx,
                    "[collect_inline_span_recursive] Found nested inline span {:?}",
                    child_dom_id
                );
                let child_style = get_style_properties(ctx.styled_dom, child_dom_id);
                collect_inline_span_recursive(
                    ctx,
                    tree,
                    child_dom_id,
                    child_style,
                    content,
                    child_map,
                    parent_children,
                    constraints,
                )?;
            }
            LayoutDisplay::InlineBlock => {
                // Inline-block inside span - measure and add as shape
                let Some(child_index) = child_index else {
                    debug_info!(
                        ctx,
                        "[collect_inline_span_recursive] WARNING: inline-block {:?} has no layout \
                         node",
                        child_dom_id
                    );
                    continue;
                };

                let child_node = tree.get(child_index).ok_or(LayoutError::InvalidTree)?;
                let intrinsic_size = child_node.intrinsic_sizes.clone().unwrap_or_default();
                let width = intrinsic_size.max_content_width;

                let styled_node_state = ctx
                    .styled_dom
                    .styled_nodes
                    .as_container()
                    .get(child_dom_id)
                    .map(|n| n.styled_node_state.clone())
                    .unwrap_or_default();
                let writing_mode =
                    get_writing_mode(ctx.styled_dom, child_dom_id, &styled_node_state)
                        .unwrap_or_default();
                let child_constraints = LayoutConstraints {
                    available_size: LogicalSize::new(width, f32::INFINITY),
                    writing_mode,
                    bfc_state: None,
                    text_align: TextAlign::Start,
                    containing_block_size: constraints.containing_block_size,
                    available_width_type: Text3AvailableSpace::Definite(width),
                };

                drop(child_node);

                let mut empty_float_cache = std::collections::BTreeMap::new();
                let layout_result = layout_formatting_context(
                    ctx,
                    tree,
                    &mut TextLayoutCache::default(),
                    child_index,
                    &child_constraints,
                    &mut empty_float_cache,
                )?;
                let final_height = layout_result.output.overflow_size.height;
                let final_size = LogicalSize::new(width, final_height);

                tree.get_mut(child_index).unwrap().used_size = Some(final_size);
                let baseline_offset = layout_result.output.baseline.unwrap_or(final_height);

                content.push(InlineContent::Shape(InlineShape {
                    shape_def: ShapeDefinition::Rectangle {
                        size: crate::text3::cache::Size {
                            width,
                            height: final_height,
                        },
                        corner_radius: None,
                    },
                    fill: None,
                    stroke: None,
                    baseline_offset,
                    source_node_id: Some(child_dom_id),
                }));

                // Note: We don't add to child_map here because this is inside a span
                debug_info!(
                    ctx,
                    "[collect_inline_span_recursive] Added inline-block shape {}x{}",
                    width,
                    final_height
                );
            }
            _ => {
                // Other display types inside span (shouldn't normally happen)
                debug_info!(
                    ctx,
                    "[collect_inline_span_recursive] WARNING: Unsupported display type {:?} \
                     inside inline span",
                    child_display
                );
            }
        }
    }

    Ok(())
}

/// Positions a floated child within the BFC and updates the floating context.
/// This function is fully writing-mode aware.
fn position_floated_child(
    _child_index: usize,
    child_margin_box_size: LogicalSize,
    float_type: LayoutFloat,
    constraints: &LayoutConstraints,
    _bfc_content_box: LogicalRect,
    current_main_offset: f32,
    floating_context: &mut FloatingContext,
) -> Result<LogicalPosition> {
    let wm = constraints.writing_mode;
    let child_main_size = child_margin_box_size.main(wm);
    let child_cross_size = child_margin_box_size.cross(wm);
    let bfc_cross_size = constraints.available_size.cross(wm);
    let mut placement_main_offset = current_main_offset;

    loop {
        // 1. Determine the available cross-axis space at the current
        // `placement_main_offset`.
        let (available_cross_start, available_cross_end) = floating_context
            .available_line_box_space(
                placement_main_offset,
                placement_main_offset + child_main_size,
                bfc_cross_size,
                wm,
            );

        let available_cross_width = available_cross_end - available_cross_start;

        // 2. Check if the new float can fit in the available space.
        if child_cross_size <= available_cross_width {
            // It fits! Determine the final position and add it to the context.
            let final_cross_pos = match float_type {
                LayoutFloat::Left => available_cross_start,
                LayoutFloat::Right => available_cross_end - child_cross_size,
                LayoutFloat::None => unreachable!(),
            };
            let final_pos =
                LogicalPosition::from_main_cross(placement_main_offset, final_cross_pos, wm);

            let new_float_box = FloatBox {
                kind: float_type,
                rect: LogicalRect::new(final_pos, child_margin_box_size),
                margin: EdgeSizes::default(), // TODO: Pass actual margin if this function is used
            };
            floating_context.floats.push(new_float_box);
            return Ok(final_pos);
        } else {
            // It doesn't fit. We must move the float down past an obstacle.
            // Find the lowest main-axis end of all floats that are blocking
            // the current line.
            let mut next_main_offset = f32::INFINITY;
            for existing_float in &floating_context.floats {
                let float_main_start = existing_float.rect.origin.main(wm);
                let float_main_end = float_main_start + existing_float.rect.size.main(wm);

                // Consider only floats that are above or at the current placement line.
                if placement_main_offset < float_main_end {
                    next_main_offset = next_main_offset.min(float_main_end);
                }
            }

            if next_main_offset.is_infinite() {
                // This indicates an unrecoverable state, e.g., a float wider
                // than the container.
                return Err(LayoutError::PositioningFailed);
            }
            placement_main_offset = next_main_offset;
        }
    }
}

// CSS Property Getters

/// Get the CSS `float` property for a node.
fn get_float_property(styled_dom: &StyledDom, dom_id: Option<NodeId>) -> LayoutFloat {
    let Some(id) = dom_id else {
        return LayoutFloat::None;
    };
    let node_data = &styled_dom.node_data.as_container()[id];
    let node_state = &styled_dom.styled_nodes.as_container()[id].styled_node_state;
    styled_dom
        .css_property_cache
        .ptr
        .get_float(node_data, &id, node_state)
        .and_then(|f| {
            f.get_property().map(|inner| match inner {
                LayoutFloat::Left => LayoutFloat::Left,
                LayoutFloat::Right => LayoutFloat::Right,
                LayoutFloat::None => LayoutFloat::None,
            })
        })
        .unwrap_or(LayoutFloat::None)
}

fn get_clear_property(styled_dom: &StyledDom, dom_id: Option<NodeId>) -> LayoutClear {
    let Some(id) = dom_id else {
        return LayoutClear::None;
    };
    let node_data = &styled_dom.node_data.as_container()[id];
    let node_state = &styled_dom.styled_nodes.as_container()[id].styled_node_state;
    styled_dom
        .css_property_cache
        .ptr
        .get_clear(node_data, &id, node_state)
        .and_then(|c| {
            c.get_property().map(|inner| match inner {
                LayoutClear::Left => LayoutClear::Left,
                LayoutClear::Right => LayoutClear::Right,
                LayoutClear::Both => LayoutClear::Both,
                LayoutClear::None => LayoutClear::None,
            })
        })
        .unwrap_or(LayoutClear::None)
}
/// Helper to determine if scrollbars are needed.
///
/// # CSS Spec Reference
/// CSS Overflow Module Level 3 § 3: Scrollable overflow
pub fn check_scrollbar_necessity(
    content_size: LogicalSize,
    container_size: LogicalSize,
    overflow_x: OverflowBehavior,
    overflow_y: OverflowBehavior,
) -> ScrollbarRequirements {
    // Use epsilon for float comparisons to avoid showing scrollbars due to 
    // floating-point rounding errors. Without this, content that exactly fits
    // may show scrollbars due to sub-pixel differences (e.g., 299.9999 vs 300.0).
    const EPSILON: f32 = 1.0;
    
    let mut needs_horizontal = match overflow_x {
        OverflowBehavior::Visible | OverflowBehavior::Hidden | OverflowBehavior::Clip => false,
        OverflowBehavior::Scroll => true,
        OverflowBehavior::Auto => content_size.width > container_size.width + EPSILON,
    };

    let mut needs_vertical = match overflow_y {
        OverflowBehavior::Visible | OverflowBehavior::Hidden | OverflowBehavior::Clip => false,
        OverflowBehavior::Scroll => true,
        OverflowBehavior::Auto => content_size.height > container_size.height + EPSILON,
    };

    // A classic layout problem: a vertical scrollbar can reduce horizontal space,
    // causing a horizontal scrollbar to appear, which can reduce vertical space...
    // A full solution involves a loop, but this two-pass check handles most cases.
    if needs_vertical && !needs_horizontal && overflow_x == OverflowBehavior::Auto {
        if content_size.width > (container_size.width - SCROLLBAR_WIDTH_PX) + EPSILON {
            needs_horizontal = true;
        }
    }
    if needs_horizontal && !needs_vertical && overflow_y == OverflowBehavior::Auto {
        if content_size.height > (container_size.height - SCROLLBAR_WIDTH_PX) + EPSILON {
            needs_vertical = true;
        }
    }

    ScrollbarRequirements {
        needs_horizontal,
        needs_vertical,
        scrollbar_width: if needs_vertical {
            SCROLLBAR_WIDTH_PX
        } else {
            0.0
        },
        scrollbar_height: if needs_horizontal {
            SCROLLBAR_WIDTH_PX
        } else {
            0.0
        },
    }
}

/// Calculates a single collapsed margin from two adjoining vertical margins.
///
/// Implements the rules from CSS 2.1 section 8.3.1:
/// - If both margins are positive, the result is the larger of the two.
/// - If both margins are negative, the result is the more negative of the two.
/// - If the margins have mixed signs, they are effectively summed.
pub(crate) fn collapse_margins(a: f32, b: f32) -> f32 {
    if a.is_sign_positive() && b.is_sign_positive() {
        a.max(b)
    } else if a.is_sign_negative() && b.is_sign_negative() {
        a.min(b)
    } else {
        a + b
    }
}

/// Helper function to advance the pen position with margin collapsing.
///
/// This implements CSS 2.1 margin collapsing for adjacent block-level boxes in a BFC.
///
/// - `pen` - Current main-axis position (will be modified)
/// - `last_margin_bottom` - The bottom margin of the previous in-flow element
/// - `current_margin_top` - The top margin of the current element
///
/// # Returns
///
/// The new `last_margin_bottom` value (the bottom margin of the current element)
///
/// # CSS Spec Compliance
///
/// Per CSS 2.1 Section 8.3.1 "Collapsing margins":
///
/// - Adjacent vertical margins of block boxes collapse
/// - The resulting margin width is the maximum of the adjoining margins (if both positive)
/// - Or the sum of the most positive and most negative (if signs differ)
fn advance_pen_with_margin_collapse(
    pen: &mut f32,
    last_margin_bottom: f32,
    current_margin_top: f32,
) -> f32 {
    // Collapse the previous element's bottom margin with current element's top margin
    let collapsed_margin = collapse_margins(last_margin_bottom, current_margin_top);

    // Advance pen by the collapsed margin
    *pen += collapsed_margin;

    // Return collapsed_margin so caller knows how much space was actually added
    collapsed_margin
}

/// Checks if an element's border or padding prevents margin collapsing.
///
/// Per CSS 2.1 Section 8.3.1:
///
/// - Border between margins prevents collapsing
/// - Padding between margins prevents collapsing
///
/// # Arguments
///
/// - `box_props` - The box properties containing border and padding
/// - `writing_mode` - The writing mode to determine main axis
/// - `check_start` - If true, check main-start (top); if false, check main-end (bottom)
///
/// # Returns
///
/// `true` if border or padding exists and prevents collapsing
fn has_margin_collapse_blocker(
    box_props: &crate::solver3::geometry::BoxProps,
    writing_mode: LayoutWritingMode,
    check_start: bool, // true = check top/start, false = check bottom/end
) -> bool {
    if check_start {
        // Check if there's border-top or padding-top
        let border_start = box_props.border.main_start(writing_mode);
        let padding_start = box_props.padding.main_start(writing_mode);
        border_start > 0.0 || padding_start > 0.0
    } else {
        // Check if there's border-bottom or padding-bottom
        let border_end = box_props.border.main_end(writing_mode);
        let padding_end = box_props.padding.main_end(writing_mode);
        border_end > 0.0 || padding_end > 0.0
    }
}

/// Checks if an element is empty (has no content).
///
/// Per CSS 2.1 Section 8.3.1:
///
/// > If a block element has no border, padding, inline content, height, or min-height,
/// > then its top and bottom margins collapse with each other.
///
/// # Arguments
///
/// - `node` - The layout node to check
///
/// # Returns
///
/// `true` if the element is empty and its margins can collapse internally
fn is_empty_block(node: &LayoutNode) -> bool {
    // Per CSS 2.2 § 8.3.1: An empty block is one that:
    // - Has zero computed 'min-height'
    // - Has zero or 'auto' computed 'height'
    // - Has no in-flow children
    // - Has no line boxes (no text/inline content)

    // Check if node has children
    if !node.children.is_empty() {
        return false;
    }

    // Check if node has inline content (text)
    if node.inline_layout_result.is_some() {
        return false;
    }

    // Check if node has explicit height > 0
    // CSS 2.2 § 8.3.1: Elements with explicit height are NOT empty
    if let Some(size) = node.used_size {
        if size.height > 0.0 {
            return false;
        }
    }

    // Empty block: no children, no inline content, no height
    true
}

/// Generates marker text for a list item marker.
///
/// This function looks up the counter value from the cache and formats it
/// according to the list-style-type property.
///
/// Per CSS Lists Module Level 3, the ::marker pseudo-element is the first child
/// of the list-item, and references the same DOM node. Counter resolution happens
/// on the list-item (parent) node.
fn generate_list_marker_text(
    tree: &LayoutTree,
    styled_dom: &StyledDom,
    marker_index: usize,
    counters: &BTreeMap<(usize, String), i32>,
    debug_messages: &mut Option<Vec<LayoutDebugMessage>>,
) -> String {
    use crate::solver3::counters::format_counter;

    // Get the marker node
    let marker_node = match tree.get(marker_index) {
        Some(n) => n,
        None => return String::new(),
    };

    // Verify this is actually a ::marker pseudo-element
    // Per spec, markers must be pseudo-elements, not anonymous boxes
    if marker_node.pseudo_element != Some(PseudoElement::Marker) {
        if let Some(msgs) = debug_messages {
            msgs.push(LayoutDebugMessage::warning(format!(
                "[generate_list_marker_text] WARNING: Node {} is not a ::marker pseudo-element \
                 (pseudo={:?}, anonymous_type={:?})",
                marker_index, marker_node.pseudo_element, marker_node.anonymous_type
            )));
        }
        // Fallback for old-style anonymous markers during transition
        if marker_node.anonymous_type != Some(AnonymousBoxType::ListItemMarker) {
            return String::new();
        }
    }

    // Get the parent list-item node (::marker is first child of list-item)
    let list_item_index = match marker_node.parent {
        Some(p) => p,
        None => {
            if let Some(msgs) = debug_messages {
                msgs.push(LayoutDebugMessage::error(
                    "[generate_list_marker_text] ERROR: Marker has no parent".to_string(),
                ));
            }
            return String::new();
        }
    };

    let list_item_node = match tree.get(list_item_index) {
        Some(n) => n,
        None => return String::new(),
    };

    let list_item_dom_id = match list_item_node.dom_node_id {
        Some(id) => id,
        None => {
            if let Some(msgs) = debug_messages {
                msgs.push(LayoutDebugMessage::error(
                    "[generate_list_marker_text] ERROR: List-item has no DOM ID".to_string(),
                ));
            }
            return String::new();
        }
    };

    if let Some(msgs) = debug_messages {
        msgs.push(LayoutDebugMessage::info(format!(
            "[generate_list_marker_text] marker_index={}, list_item_index={}, \
             list_item_dom_id={:?}",
            marker_index, list_item_index, list_item_dom_id
        )));
    }

    // Get list-style-type from the list-item or its container
    let list_container_dom_id = if let Some(grandparent_index) = list_item_node.parent {
        if let Some(grandparent) = tree.get(grandparent_index) {
            grandparent.dom_node_id
        } else {
            None
        }
    } else {
        None
    };

    // Try to get list-style-type from the list container first,
    // then fall back to the list-item
    let list_style_type = if let Some(container_id) = list_container_dom_id {
        let container_type = get_list_style_type(styled_dom, Some(container_id));
        if container_type != StyleListStyleType::default() {
            container_type
        } else {
            get_list_style_type(styled_dom, Some(list_item_dom_id))
        }
    } else {
        get_list_style_type(styled_dom, Some(list_item_dom_id))
    };

    // Get the counter value for "list-item" counter from the LIST-ITEM node
    // Per CSS spec, counters are scoped to elements, and the list-item counter
    // is incremented at the list-item element, not the marker pseudo-element
    let counter_value = counters
        .get(&(list_item_index, "list-item".to_string()))
        .copied()
        .unwrap_or_else(|| {
            if let Some(msgs) = debug_messages {
                msgs.push(LayoutDebugMessage::warning(format!(
                    "[generate_list_marker_text] WARNING: No counter found for list-item at index \
                     {}, defaulting to 1",
                    list_item_index
                )));
            }
            1
        });

    if let Some(msgs) = debug_messages {
        msgs.push(LayoutDebugMessage::info(format!(
            "[generate_list_marker_text] counter_value={} for list_item_index={}",
            counter_value, list_item_index
        )));
    }

    // Format the counter according to the list-style-type
    let marker_text = format_counter(counter_value, list_style_type);

    // For ordered lists (non-symbolic markers), add a period and space
    // For unordered lists (symbolic markers like •, ◦, ▪), just add a space
    if matches!(
        list_style_type,
        StyleListStyleType::Decimal
            | StyleListStyleType::DecimalLeadingZero
            | StyleListStyleType::LowerAlpha
            | StyleListStyleType::UpperAlpha
            | StyleListStyleType::LowerRoman
            | StyleListStyleType::UpperRoman
            | StyleListStyleType::LowerGreek
            | StyleListStyleType::UpperGreek
    ) {
        format!("{}. ", marker_text)
    } else {
        format!("{} ", marker_text)
    }
}

/// Generates marker text segments for a list item marker.
///
/// Simply returns a single StyledRun with the marker text using the base_style.
/// The font stack in base_style already includes fallbacks with 100% Unicode coverage,
/// so font resolution happens during text shaping, not here.
fn generate_list_marker_segments(
    tree: &LayoutTree,
    styled_dom: &StyledDom,
    marker_index: usize,
    counters: &BTreeMap<(usize, String), i32>,
    base_style: Arc<StyleProperties>,
    debug_messages: &mut Option<Vec<LayoutDebugMessage>>,
) -> Vec<StyledRun> {
    // Generate the marker text
    let marker_text =
        generate_list_marker_text(tree, styled_dom, marker_index, counters, debug_messages);
    if marker_text.is_empty() {
        return Vec::new();
    }

    if let Some(msgs) = debug_messages {
        let font_families: Vec<&str> = match &base_style.font_stack {
            crate::text3::cache::FontStack::Stack(selectors) => {
                selectors.iter().map(|f| f.family.as_str()).collect()
            }
            crate::text3::cache::FontStack::Ref(_) => vec!["<embedded-font>"],
        };
        msgs.push(LayoutDebugMessage::info(format!(
            "[generate_list_marker_segments] Marker text: '{}' with font stack: {:?}",
            marker_text,
            font_families
        )));
    }

    // Return single segment - font fallback happens during shaping
    // List markers are generated content, not from DOM nodes
    vec![StyledRun {
        text: marker_text,
        style: base_style,
        logical_start_byte: 0,
        source_node_id: None,
    }]
}

/// Splits text content into InlineContent items based on white-space CSS property.
///
/// For `white-space: pre`, `pre-wrap`, and `pre-line`, newlines (`\n`) are treated as
/// forced line breaks per CSS Text Level 3 specification:
/// https://www.w3.org/TR/css-text-3/#white-space-property
///
/// This function:
/// 1. Checks the white-space property of the node (or its parent for text nodes)
/// 2. If `pre`, `pre-wrap`, or `pre-line`: splits text by `\n` and inserts `InlineContent::LineBreak`
/// 3. Otherwise: returns the text as a single `InlineContent::Text`
///
/// Returns a Vec of InlineContent items that correctly represent line breaks.
pub(crate) fn split_text_for_whitespace(
    styled_dom: &StyledDom,
    dom_id: NodeId,
    text: &str,
    style: Arc<StyleProperties>,
) -> Vec<InlineContent> {
    use crate::text3::cache::{BreakType, ClearType, InlineBreak};
    
    // Get the white-space property - TEXT NODES inherit from parent!
    // We need to check the parent element's white-space, not the text node itself
    let node_hierarchy = styled_dom.node_hierarchy.as_container();
    let parent_id = node_hierarchy[dom_id].parent_id();
    
    // Try parent first, then fall back to the node itself
    let white_space = if let Some(parent) = parent_id {
        let parent_node_data = &styled_dom.node_data.as_container()[parent];
        let styled_nodes = styled_dom.styled_nodes.as_container();
        let parent_state = styled_nodes
            .get(parent)
            .map(|n| n.styled_node_state.clone())
            .unwrap_or_default();
        
        styled_dom
            .css_property_cache
            .ptr
            .get_white_space(parent_node_data, &parent, &parent_state)
            .and_then(|s| s.get_property().cloned())
            .unwrap_or(StyleWhiteSpace::Normal)
    } else {
        StyleWhiteSpace::Normal
    };
    
    let mut result = Vec::new();
    
    // For `pre`, `pre-wrap`, and `pre-line`, newlines must be preserved as forced breaks
    // CSS Text Level 3: "Newlines in the source will be honored as forced line breaks."
    match white_space {
        StyleWhiteSpace::Pre => {
            // Split by newlines and insert LineBreak between parts
            let mut lines = text.split('\n').peekable();
            let mut content_index = 0;
            
            while let Some(line) = lines.next() {
                // Add the text part if not empty
                if !line.is_empty() {
                    result.push(InlineContent::Text(StyledRun {
                        text: line.to_string(),
                        style: Arc::clone(&style),
                        logical_start_byte: 0,
                        source_node_id: Some(dom_id),
                    }));
                }
                
                // If there's more content, insert a forced line break
                if lines.peek().is_some() {
                    result.push(InlineContent::LineBreak(InlineBreak {
                        break_type: BreakType::Hard,
                        clear: ClearType::None,
                        content_index,
                    }));
                    content_index += 1;
                }
            }
        }
        // TODO: Implement pre-wrap and pre-line when CSS parser supports them
        StyleWhiteSpace::Normal | StyleWhiteSpace::Nowrap => {
            // Normal behavior: newlines are collapsed to spaces
            if !text.is_empty() {
                result.push(InlineContent::Text(StyledRun {
                    text: text.to_string(),
                    style,
                    logical_start_byte: 0,
                    source_node_id: Some(dom_id),
                }));
            }
        }
    }
    
    result
}