azul_core/

prop_cache.rs

//! CSS property cache for efficient style resolution and animation.
//!
//! This module implements a cache layer between the raw CSS stylesheet and the rendered DOM.
//! It resolves CSS properties for each node, handling:
//!
//! - **Cascade resolution**: Computes final values from CSS rules, inline styles, and inheritance
//! - **Pseudo-class states**: Caches styles for `:hover`, `:active`, `:focus`, etc.
//! - **Animation support**: Tracks animating properties for smooth interpolation
//! - **Performance**: Avoids re-parsing and re-resolving unchanged properties
//!
//! # Architecture
//!
//! The cache is organized per-node and per-property-type. Each property has a dedicated
//! getter method that:
//!
//! 1. Checks if the property is cached
//! 2. If not, resolves it from CSS rules + inline styles
//! 3. Caches the result for subsequent frames
//!
//! # Thread Safety
//!
//! Not thread-safe. Each window has its own cache instance.

extern crate alloc;

use alloc::{boxed::Box, string::String, vec::Vec};
use core::fmt::Write;
use core::mem::ManuallyDrop;

use crate::dom::NodeType;

/// Tracks the origin of a CSS property value.
/// Used to correctly implement the CSS cascade and inheritance rules.
#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
pub enum CssPropertyOrigin {
    /// Property was inherited from parent node (only for inheritable properties)
    Inherited,
    /// Property is the node's own value (from UA CSS, CSS file, inline style, or user override)
    Own,
}

/// A CSS property with its origin tracking.
#[derive(Debug, Clone, PartialEq, Eq)]
pub struct CssPropertyWithOrigin {
    pub property: CssProperty,
    pub origin: CssPropertyOrigin,
}

use azul_css::{
    css::{Css, CssPath},
    props::{
        basic::{StyleFontFamily, StyleFontFamilyVec, StyleFontSize},
        layout::{LayoutDisplay, LayoutHeight, LayoutWidth},
        property::{
            BoxDecorationBreakValue, BreakInsideValue, CaretAnimationDurationValue,
            CaretColorValue, CaretWidthValue, ClipPathValue, ColumnCountValue, ColumnFillValue,
            ColumnRuleColorValue, ColumnRuleStyleValue, ColumnRuleWidthValue, ColumnSpanValue,
            ColumnWidthValue, ContentValue, CounterIncrementValue, CounterResetValue, CssProperty,
            CssPropertyType, FlowFromValue, FlowIntoValue, LayoutAlignContentValue,
            LayoutAlignItemsValue, LayoutAlignSelfValue, LayoutBorderBottomWidthValue,
            LayoutBorderLeftWidthValue, LayoutBorderRightWidthValue, LayoutBorderSpacingValue,
            LayoutBorderTopWidthValue, LayoutBoxSizingValue, LayoutClearValue,
            LayoutColumnGapValue, LayoutDisplayValue, LayoutFlexBasisValue,
            LayoutFlexDirectionValue, LayoutFlexGrowValue, LayoutFlexShrinkValue,
            LayoutFlexWrapValue, LayoutFloatValue, LayoutGapValue, LayoutGridAutoColumnsValue,
            LayoutGridAutoFlowValue, LayoutGridAutoRowsValue, LayoutGridColumnValue,
            LayoutGridRowValue, LayoutGridTemplateColumnsValue, LayoutGridTemplateRowsValue,
            LayoutHeightValue, LayoutInsetBottomValue, LayoutJustifyContentValue,
            LayoutJustifyItemsValue, LayoutJustifySelfValue, LayoutLeftValue,
            LayoutMarginBottomValue, LayoutMarginLeftValue, LayoutMarginRightValue,
            LayoutMarginTopValue, LayoutMaxHeightValue, LayoutMaxWidthValue, LayoutMinHeightValue,
            LayoutMinWidthValue, LayoutOverflowValue, LayoutPaddingBottomValue,
            LayoutPaddingLeftValue, LayoutPaddingRightValue, LayoutPaddingTopValue,
            LayoutPositionValue, LayoutRightValue, LayoutRowGapValue, LayoutScrollbarWidthValue,
            LayoutTableLayoutValue, LayoutTextJustifyValue, LayoutTopValue, LayoutWidthValue,
            LayoutWritingModeValue, LayoutZIndexValue, OrphansValue, PageBreakValue,
            StyleBackgroundContentValue, ScrollbarFadeDelayValue, ScrollbarFadeDurationValue,
            ScrollbarVisibilityModeValue, SelectionBackgroundColorValue, SelectionColorValue,
            SelectionRadiusValue, ShapeImageThresholdValue, ShapeInsideValue, ShapeMarginValue,
            ShapeOutsideValue, StringSetValue, StyleBackfaceVisibilityValue,
            StyleBackgroundContentVecValue, StyleBackgroundPositionVecValue,
            StyleBackgroundRepeatVecValue, StyleBackgroundSizeVecValue,
            StyleBorderBottomColorValue, StyleBorderBottomLeftRadiusValue,
            StyleBorderBottomRightRadiusValue, StyleBorderBottomStyleValue,
            StyleBorderCollapseValue, StyleBorderLeftColorValue, StyleBorderLeftStyleValue,
            StyleBorderRightColorValue, StyleBorderRightStyleValue, StyleBorderTopColorValue,
            StyleBorderTopLeftRadiusValue, StyleBorderTopRightRadiusValue,
            StyleBorderTopStyleValue, StyleBoxShadowValue, StyleCaptionSideValue, StyleCursorValue,
            StyleDirectionValue, StyleEmptyCellsValue, StyleExclusionMarginValue,
            StyleFilterVecValue, StyleFontFamilyVecValue, StyleFontSizeValue, StyleFontStyleValue,
            StyleFontValue, StyleFontWeightValue, StyleHangingPunctuationValue,
            StyleHyphenationLanguageValue, StyleHyphensValue, StyleInitialLetterValue,
            StyleLetterSpacingValue, StyleLineBreakValue, StyleLineClampValue, StyleLineHeightValue,
            StyleListStylePositionValue, StyleListStyleTypeValue, StyleMixBlendModeValue,
            StyleAspectRatioValue, StyleObjectFitValue, StyleObjectPositionValue, StyleTextOverflowValue,
            StyleOpacityValue, StylePerspectiveOriginValue,
            StyleScrollbarColorValue, StyleOverflowWrapValue, StyleTabSizeValue,
            StyleTextAlignLastValue, StyleTextOrientationValue, StyleTextTransformValue,
            StyleTextAlignValue, StyleTextColorValue,
            StyleTextCombineUprightValue, StyleUnicodeBidiValue,
            StyleTextBoxTrimValue, StyleTextBoxEdgeValue,
            StyleDominantBaselineValue, StyleAlignmentBaselineValue, StyleBaselineSourceValue,
            StyleLineFitEdgeValue,
            StyleInitialLetterAlignValue, StyleInitialLetterWrapValue,
            StyleScrollbarGutterValue, StyleOverflowClipMarginValue, StyleClipRectValue,
            StyleTextDecorationValue, StyleTextIndentValue,
            StyleTransformOriginValue, StyleTransformVecValue, StyleUserSelectValue,
            StyleVerticalAlignValue, StyleVisibilityValue, StyleWhiteSpaceValue,
            StyleWordBreakValue, StyleWordSpacingValue, WidowsValue,
        },
        style::{StyleCursor, StyleTextColor, StyleTransformOrigin},
    },
    AzString,
};

use crate::{
    dom::{NodeData, NodeId, TabIndex, TagId},
    id::{NodeDataContainer, NodeDataContainerRef},
    style::CascadeInfo,
    styled_dom::{
        NodeHierarchyItem, NodeHierarchyItemId, NodeHierarchyItemVec, ParentWithNodeDepth,
        ParentWithNodeDepthVec, StyledNodeState, TagIdToNodeIdMapping,
    },
};

use azul_css::dynamic_selector::{
    CssPropertyWithConditions, CssPropertyWithConditionsVec, DynamicSelectorContext,
};

#[cfg(feature = "std")]
std::thread_local! {
    static PROP_COUNTS: core::cell::RefCell<
        std::collections::HashMap<&'static str, usize>
    > = core::cell::RefCell::new(std::collections::HashMap::new());
}

/// Drain the per-thread CSS cascade-walk counter populated by
/// [`CssPropertyCache::get_property`] when `AZ_PROP_COUNT=1` is set
/// in the environment.
///
/// Returns `(property_label, count)` pairs
/// sorted by count descending. Layout-side instrumentation calls
/// this after each `layout_document` to print which properties
/// drove the most cascade walks.
#[cfg(feature = "std")]
#[must_use] pub fn drain_css_prop_counts() -> Vec<(&'static str, usize)> {
    // try_with: no real TLS in the lifted-to-wasm web backend (see the
    // get_property recording site) — return empty rather than panic.
    PROP_COUNTS
        .try_with(|c| {
            let map = core::mem::take(&mut *c.borrow_mut());
            let mut v: Vec<_> = map.into_iter().collect();
            v.sort_by(|a, b| b.1.cmp(&a.1));
            v
        })
        .unwrap_or_default()
}

// Unit conversion constants (CSS absolute units → pixels)
const PT_TO_PX: f32 = 1.333_333;
const IN_TO_PX: f32 = 96.0;
const CM_TO_PX: f32 = 37.795_277;
const MM_TO_PX: f32 = 3.779_527_7;

/// Match on any `CssProperty` variant and access the inner `CssPropertyValue`<T>.
#[allow(unused_macros)]
macro_rules! match_property_value {
    ($property:expr, $value:ident, $expr:expr) => {
        match $property {
            CssProperty::CaretColor($value) => $expr,
            CssProperty::CaretAnimationDuration($value) => $expr,
            CssProperty::SelectionBackgroundColor($value) => $expr,
            CssProperty::SelectionColor($value) => $expr,
            CssProperty::SelectionRadius($value) => $expr,
            CssProperty::TextColor($value) => $expr,
            CssProperty::FontSize($value) => $expr,
            CssProperty::FontFamily($value) => $expr,
            CssProperty::FontWeight($value) => $expr,
            CssProperty::FontStyle($value) => $expr,
            CssProperty::TextAlign($value) => $expr,
            CssProperty::TextJustify($value) => $expr,
            CssProperty::VerticalAlign($value) => $expr,
            CssProperty::LetterSpacing($value) => $expr,
            CssProperty::TextIndent($value) => $expr,
            CssProperty::InitialLetter($value) => $expr,
            CssProperty::LineClamp($value) => $expr,
            CssProperty::HangingPunctuation($value) => $expr,
            CssProperty::TextCombineUpright($value) => $expr,
            CssProperty::UnicodeBidi($value) => $expr,
            CssProperty::TextBoxTrim($value) => $expr,
            CssProperty::TextBoxEdge($value) => $expr,
            CssProperty::DominantBaseline($value) => $expr,
            CssProperty::AlignmentBaseline($value) => $expr,
            CssProperty::BaselineSource($value) => $expr,
            CssProperty::LineFitEdge($value) => $expr,
            CssProperty::InitialLetterAlign($value) => $expr,
            CssProperty::InitialLetterWrap($value) => $expr,
            CssProperty::ScrollbarGutter($value) => $expr,
            CssProperty::OverflowClipMargin($value) => $expr,
            CssProperty::Clip($value) => $expr,
            CssProperty::ExclusionMargin($value) => $expr,
            CssProperty::HyphenationLanguage($value) => $expr,
            CssProperty::LineHeight($value) => $expr,
            CssProperty::WordSpacing($value) => $expr,
            CssProperty::TabSize($value) => $expr,
            CssProperty::WhiteSpace($value) => $expr,
            CssProperty::Hyphens($value) => $expr,
            CssProperty::Direction($value) => $expr,
            CssProperty::UserSelect($value) => $expr,
            CssProperty::TextDecoration($value) => $expr,
            CssProperty::Cursor($value) => $expr,
            CssProperty::Display($value) => $expr,
            CssProperty::Float($value) => $expr,
            CssProperty::BoxSizing($value) => $expr,
            CssProperty::Width($value) => $expr,
            CssProperty::Height($value) => $expr,
            CssProperty::MinWidth($value) => $expr,
            CssProperty::MinHeight($value) => $expr,
            CssProperty::MaxWidth($value) => $expr,
            CssProperty::MaxHeight($value) => $expr,
            CssProperty::Position($value) => $expr,
            CssProperty::Top($value) => $expr,
            CssProperty::Right($value) => $expr,
            CssProperty::Left($value) => $expr,
            CssProperty::Bottom($value) => $expr,
            CssProperty::ZIndex($value) => $expr,
            CssProperty::FlexWrap($value) => $expr,
            CssProperty::FlexDirection($value) => $expr,
            CssProperty::FlexGrow($value) => $expr,
            CssProperty::FlexShrink($value) => $expr,
            CssProperty::FlexBasis($value) => $expr,
            CssProperty::JustifyContent($value) => $expr,
            CssProperty::AlignItems($value) => $expr,
            CssProperty::AlignContent($value) => $expr,
            CssProperty::AlignSelf($value) => $expr,
            CssProperty::JustifyItems($value) => $expr,
            CssProperty::JustifySelf($value) => $expr,
            CssProperty::BackgroundContent($value) => $expr,
            CssProperty::BackgroundPosition($value) => $expr,
            CssProperty::BackgroundSize($value) => $expr,
            CssProperty::BackgroundRepeat($value) => $expr,
            CssProperty::OverflowX($value) => $expr,
            CssProperty::OverflowY($value) => $expr,
            CssProperty::OverflowBlock($value) => $expr,
            CssProperty::OverflowInline($value) => $expr,
            CssProperty::PaddingTop($value) => $expr,
            CssProperty::PaddingLeft($value) => $expr,
            CssProperty::PaddingRight($value) => $expr,
            CssProperty::PaddingBottom($value) => $expr,
            CssProperty::MarginTop($value) => $expr,
            CssProperty::MarginLeft($value) => $expr,
            CssProperty::MarginRight($value) => $expr,
            CssProperty::MarginBottom($value) => $expr,
            CssProperty::BorderTopLeftRadius($value) => $expr,
            CssProperty::BorderTopRightRadius($value) => $expr,
            CssProperty::BorderBottomLeftRadius($value) => $expr,
            CssProperty::BorderBottomRightRadius($value) => $expr,
            CssProperty::BorderTopColor($value) => $expr,
            CssProperty::BorderRightColor($value) => $expr,
            CssProperty::BorderLeftColor($value) => $expr,
            CssProperty::BorderBottomColor($value) => $expr,
            CssProperty::BorderTopStyle($value) => $expr,
            CssProperty::BorderRightStyle($value) => $expr,
            CssProperty::BorderLeftStyle($value) => $expr,
            CssProperty::BorderBottomStyle($value) => $expr,
            CssProperty::BorderTopWidth($value) => $expr,
            CssProperty::BorderRightWidth($value) => $expr,
            CssProperty::BorderLeftWidth($value) => $expr,
            CssProperty::BorderBottomWidth($value) => $expr,
            CssProperty::BoxShadow($value) => $expr,
            CssProperty::Opacity($value) => $expr,
            CssProperty::Transform($value) => $expr,
            CssProperty::TransformOrigin($value) => $expr,
            CssProperty::PerspectiveOrigin($value) => $expr,
            CssProperty::BackfaceVisibility($value) => $expr,
            CssProperty::MixBlendMode($value) => $expr,
            CssProperty::Filter($value) => $expr,
            CssProperty::Visibility($value) => $expr,
            CssProperty::WritingMode($value) => $expr,
            CssProperty::GridTemplateColumns($value) => $expr,
            CssProperty::GridTemplateRows($value) => $expr,
            CssProperty::GridAutoColumns($value) => $expr,
            CssProperty::GridAutoRows($value) => $expr,
            CssProperty::GridAutoFlow($value) => $expr,
            CssProperty::GridColumn($value) => $expr,
            CssProperty::GridRow($value) => $expr,
            CssProperty::GridTemplateAreas($value) => $expr,
            CssProperty::Gap($value) => $expr,
            CssProperty::ColumnGap($value) => $expr,
            CssProperty::RowGap($value) => $expr,
            CssProperty::Clear($value) => $expr,
            CssProperty::ScrollbarTrack($value) => $expr,
            CssProperty::ScrollbarThumb($value) => $expr,
            CssProperty::ScrollbarButton($value) => $expr,
            CssProperty::ScrollbarCorner($value) => $expr,
            CssProperty::ScrollbarResizer($value) => $expr,
            CssProperty::ScrollbarWidth($value) => $expr,
            CssProperty::ScrollbarColor($value) => $expr,
            CssProperty::ListStyleType($value) => $expr,
            CssProperty::ListStylePosition($value) => $expr,
            CssProperty::Font($value) => $expr,
            CssProperty::ColumnCount($value) => $expr,
            CssProperty::ColumnWidth($value) => $expr,
            CssProperty::ColumnSpan($value) => $expr,
            CssProperty::ColumnFill($value) => $expr,
            CssProperty::ColumnRuleStyle($value) => $expr,
            CssProperty::ColumnRuleWidth($value) => $expr,
            CssProperty::ColumnRuleColor($value) => $expr,
            CssProperty::FlowInto($value) => $expr,
            CssProperty::FlowFrom($value) => $expr,
            CssProperty::ShapeOutside($value) => $expr,
            CssProperty::ShapeInside($value) => $expr,
            CssProperty::ShapeImageThreshold($value) => $expr,
            CssProperty::ShapeMargin($value) => $expr,
            CssProperty::ClipPath($value) => $expr,
            CssProperty::Content($value) => $expr,
            CssProperty::CounterIncrement($value) => $expr,
            CssProperty::CounterReset($value) => $expr,
            CssProperty::StringSet($value) => $expr,
            CssProperty::Orphans($value) => $expr,
            CssProperty::Widows($value) => $expr,
            CssProperty::PageBreakBefore($value) => $expr,
            CssProperty::PageBreakAfter($value) => $expr,
            CssProperty::PageBreakInside($value) => $expr,
            CssProperty::BreakInside($value) => $expr,
            CssProperty::BoxDecorationBreak($value) => $expr,
            CssProperty::TableLayout($value) => $expr,
            CssProperty::BorderCollapse($value) => $expr,
            CssProperty::BorderSpacing($value) => $expr,
            CssProperty::CaptionSide($value) => $expr,
            CssProperty::EmptyCells($value) => $expr,
        }
    };
}

/// A CSS property tagged with its pseudo-state and property type.
///
/// Replaces the per-pseudo-state `BTreeMap` approach: instead of 6 `BTreeMaps`
/// per node (Normal/Hover/Active/Focus/Dragging/DragOver), we store one Vec
/// per node and tag each property with its state. Lookups use `.iter().find()`.
#[derive(Debug, Clone, PartialEq, Eq)]
pub struct StatefulCssProperty {
    pub state: azul_css::dynamic_selector::PseudoStateType,
    pub prop_type: CssPropertyType,
    pub property: CssProperty,
}

// =============================================================================
// FlatVecVec: Cache-friendly replacement for Vec<Vec<T>>
// =============================================================================

/// A flat, cache-friendly replacement for `Vec<Vec<T>>`.
///
/// During the **build phase**, items are pushed into per-node inner Vecs
/// (same as before). After building is complete, `flatten()` compacts all
/// inner Vecs into a single contiguous `Vec<T>` with a `(start, len)` offset
/// table per node. All subsequent reads use the flat layout, eliminating
/// N heap allocations and pointer chasing.
///
/// ## Lifecycle
///
/// ```text
/// new(n) → push_to(idx, item)* → sort_each_and_flatten(key_fn) → get_slice(idx)*
///          ── build phase ──       ── transition ──                ── read phase ──
/// ```
#[derive(Debug, Clone)]
pub struct FlatVecVec<T> {
    /// Per-node inner Vecs (used during build phase, empty after flatten).
    build: Vec<Vec<T>>,
    /// Flat contiguous storage (populated after flatten).
    data: Vec<T>,
    /// `(start, len)` offsets into `data` for each node (populated after flatten).
    offsets: Vec<(u32, u32)>,
}

impl<T: PartialEq> PartialEq for FlatVecVec<T> {
    fn eq(&self, other: &Self) -> bool {
        let self_in_build = !self.build.is_empty() && self.offsets.is_empty();
        let other_in_build = !other.build.is_empty() && other.offsets.is_empty();
        debug_assert!(
            self_in_build == other_in_build,
            "FlatVecVec::eq called across phases (one build, one flattened)"
        );
        if self_in_build || other_in_build {
            self.build == other.build
        } else {
            self.data == other.data && self.offsets == other.offsets
        }
    }
}

impl<T> Default for FlatVecVec<T> {
    fn default() -> Self {
        Self {
            build: Vec::new(),
            data: Vec::new(),
            offsets: Vec::new(),
        }
    }
}

impl<T> FlatVecVec<T> {
    /// Approximate heap bytes retained. Sums capacity of the
    /// flattened `data` + `offsets` tables and the per-node build
    /// Vecs (in case `sort_each_and_flatten` hasn't been called
    /// yet). `per_element_size` should be `size_of::<T>()`.
    #[must_use] pub fn heap_bytes(&self, per_element_size: usize) -> usize {
        let data_bytes = self.data.capacity() * per_element_size;
        let offsets_bytes =
            self.offsets.capacity() * size_of::<(u32, u32)>();
        let mut build_bytes = self.build.capacity() * size_of::<Vec<T>>();
        for v in &self.build {
            build_bytes += v.capacity() * per_element_size;
        }
        data_bytes + offsets_bytes + build_bytes
    }

    /// Create a new `FlatVecVec` with `node_count` empty slots (build phase).
    #[must_use] pub fn new(node_count: usize) -> Self {
        let mut build = Vec::with_capacity(node_count);
        for _ in 0..node_count {
            build.push(Vec::new());
        }
        Self {
            build,
            data: Vec::new(),
            offsets: Vec::new(),
        }
    }

    /// Push an item to the inner Vec at `node_index` (build phase).
    ///
    /// # Panics
    /// Panics if already flattened or if `node_index >= len()`.
    #[inline]
    pub fn push_to(&mut self, node_index: usize, item: T) {
        self.build[node_index].push(item);
    }

    /// Get a mutable reference to the inner Vec at `node_index` (build phase).
    #[inline]
    pub fn build_mut(&mut self, node_index: usize) -> &mut Vec<T> {
        &mut self.build[node_index]
    }

    /// Iterate mutably over all inner Vecs (build phase, e.g. for clearing).
    #[inline]
    pub fn build_iter_mut(&mut self) -> core::slice::IterMut<'_, Vec<T>> {
        self.build.iter_mut()
    }

    /// Get a reference to the inner Vec at `node_index` during build phase.
    /// During read phase, returns None (use `get_slice` instead).
    #[inline]
    #[must_use] pub fn build_get(&self, node_index: usize) -> Option<&Vec<T>> {
        self.build.get(node_index)
    }

    /// Number of node slots.
    #[inline]
    #[must_use] pub const fn len(&self) -> usize {
        if self.offsets.is_empty() {
            self.build.len()
        } else {
            self.offsets.len()
        }
    }

    /// Returns `true` if there are no node slots.
    #[inline]
    #[must_use] pub const fn is_empty(&self) -> bool {
        self.len() == 0
    }

    /// Returns true if this is in read (flattened) mode.
    #[inline]
    #[must_use] pub const fn is_flattened(&self) -> bool {
        !self.offsets.is_empty() || self.build.is_empty()
    }

    /// Get a slice for the node at `node_index` (read phase).
    /// Returns empty slice if index is out of bounds or not yet flattened
    /// (falls back to build-phase data if not yet flattened).
    #[inline]
    #[must_use] pub fn get_slice(&self, node_index: usize) -> &[T] {
        if self.offsets.is_empty() {
            // Build phase fallback: use inner Vecs
            self.build.get(node_index).map_or(&[], alloc::vec::Vec::as_slice)
        } else {
            // Read phase: use flat data
            if let Some(&(start, len)) = self.offsets.get(node_index) {
                let s = start as usize;
                let l = len as usize;
                &self.data[s..s + l]
            } else {
                &[]
            }
        }
    }

    /// Flatten: sort each inner Vec by key, deduplicate by keeping the last
    /// occurrence of each key (CSS cascade: later source order wins among
    /// equal specificity), then compact into flat storage.
    /// Drains all build-phase Vecs. After this call, only `get_slice()` works.
    pub fn sort_each_and_flatten<K: Ord + Eq>(&mut self, key_fn: impl Fn(&T) -> K) {
        let node_count = self.build.len();
        let total: usize = self.build.iter().map(alloc::vec::Vec::len).sum();

        let mut flat_data = Vec::with_capacity(total);
        let mut offsets = Vec::with_capacity(node_count);

        for inner in &mut self.build {
            inner.sort_by_key(|a| key_fn(a));

            // Deduplicate: keep last of each consecutive-key group (CSS cascade).
            let n = inner.len();
            let mut keep = vec![false; n];
            for i in 0..n {
                if i + 1 >= n || key_fn(&inner[i]) != key_fn(&inner[i + 1]) {
                    keep[i] = true;
                }
            }

            let start = u32::try_from(flat_data.len()).unwrap_or(u32::MAX);
            // Drain inner and push only kept items
            for (i, item) in inner.drain(..).enumerate() {
                if keep[i] {
                    flat_data.push(item);
                }
            }

            let len = u32::try_from(flat_data.len()).unwrap_or(u32::MAX) - start;
            offsets.push((start, len));
        }

        flat_data.shrink_to_fit();
        self.data = flat_data;
        self.offsets = offsets;
        self.build = Vec::new();
    }

    /// Flatten without sorting (for data that's already sorted).
    pub fn flatten(&mut self) {
        let node_count = self.build.len();
        let total: usize = self.build.iter().map(alloc::vec::Vec::len).sum();

        let mut flat_data = Vec::with_capacity(total);
        let mut offsets = Vec::with_capacity(node_count);

        for inner in &mut self.build {
            let start = u32::try_from(flat_data.len()).unwrap_or(u32::MAX);
            let len = u32::try_from(inner.len()).unwrap_or(u32::MAX);
            offsets.push((start, len));
            flat_data.append(inner);
        }

        self.data = flat_data;
        self.offsets = offsets;
        self.build = Vec::new();
    }

    /// Rebuild flat storage, keeping only items matching `predicate`.
    /// Must be called after flatten. Preserves per-node ordering.
    pub fn retain(&mut self, predicate: impl Fn(&T) -> bool) where T: Clone {
        if self.offsets.is_empty() { return; }
        let node_count = self.offsets.len();
        let mut new_data = Vec::new();
        let mut new_offsets = Vec::with_capacity(node_count);
        for &(start, len) in &self.offsets {
            let s = start as usize;
            let l = len as usize;
            let new_start = u32::try_from(new_data.len()).unwrap_or(u32::MAX);
            let slice = &self.data[s..s + l];
            let mut kept = 0u32;
            for item in slice {
                if predicate(item) {
                    new_data.push((*item).clone());
                    kept += 1;
                }
            }
            new_offsets.push((new_start, kept));
        }
        new_data.shrink_to_fit();
        self.data = new_data;
        self.offsets = new_offsets;
    }

    /// Return to build phase from read (flattened) phase, preserving all data, so
    /// `push_to` / `build_mut` work again. No-op if already in build phase.
    ///
    /// The build → flatten → read progression is otherwise one-way, but `restyle()`
    /// legitimately runs more than once on the same cache (`StyledDom::create` does one
    /// internal pass, then the public API may do more), and building the compact cache
    /// flattens these vecs in between. Without re-entering build phase, the next
    /// restyle's `push_to` / `build_mut` would index an emptied `build` and panic.
    pub fn ensure_build_phase(&mut self) where T: Clone {
        if self.offsets.is_empty() {
            return; // already in build phase (or wholly empty)
        }
        let mut build = Vec::with_capacity(self.offsets.len());
        for &(start, len) in &self.offsets {
            let s = start as usize;
            let l = len as usize;
            build.push(self.data[s..s + l].to_vec());
        }
        self.build = build;
        self.data = Vec::new();
        self.offsets = Vec::new();
    }

    /// Like `retain`, but passes each item's owning node index to the predicate.
    /// Must be called after flatten. Preserves per-node ordering.
    pub fn retain_with_node_index(
        &mut self,
        predicate: impl Fn(usize, &T) -> bool,
    ) where T: Clone {
        if self.offsets.is_empty() { return; }
        let node_count = self.offsets.len();
        let mut new_data = Vec::new();
        let mut new_offsets = Vec::with_capacity(node_count);
        for (node_idx, &(start, len)) in self.offsets.iter().enumerate() {
            let s = start as usize;
            let l = len as usize;
            let new_start = u32::try_from(new_data.len()).unwrap_or(u32::MAX);
            let slice = &self.data[s..s + l];
            let mut kept = 0u32;
            for item in slice {
                if predicate(node_idx, item) {
                    new_data.push((*item).clone());
                    kept += 1;
                }
            }
            new_offsets.push((new_start, kept));
        }
        new_data.shrink_to_fit();
        self.data = new_data;
        self.offsets = new_offsets;
    }

    /// Iterate over all nodes, yielding (`node_index`, &[T]) for each.
    /// Works in both build and flattened phases.
    pub(crate) const fn iter_node_slices(&self) -> FlatVecVecIter<'_, T> {
        FlatVecVecIter {
            fvv: self,
            idx: 0,
            count: self.len(),
        }
    }

    /// Extend this `FlatVecVec` with all nodes from `other` (append for DOM merge).
    /// Both must be in build phase, or both must be flattened.
    pub fn extend_from(&mut self, other: &mut Self) {
        if !self.offsets.is_empty() && !other.offsets.is_empty() {
            // Both flattened: extend flat data with offset adjustment
            let base = u32::try_from(self.data.len()).unwrap_or(u32::MAX);
            self.data.append(&mut other.data);
            self.offsets.extend(other.offsets.drain(..).map(|(s, l)| (s + base, l)));
        } else {
            // At least one in build phase: extend build vecs
            self.build.append(&mut other.build);
            // Invalidate flat data if it existed
            self.data.clear();
            self.offsets.clear();
        }
    }
}

/// Iterator over (`node_index`, &[T]) pairs from a `FlatVecVec`.
pub(crate) struct FlatVecVecIter<'a, T> {
    fvv: &'a FlatVecVec<T>,
    idx: usize,
    count: usize,
}

impl<'a, T> Iterator for FlatVecVecIter<'a, T> {
    type Item = (usize, &'a [T]);

    #[inline]
    fn next(&mut self) -> Option<Self::Item> {
        if self.idx >= self.count {
            return None;
        }
        let i = self.idx;
        self.idx += 1;
        Some((i, self.fvv.get_slice(i)))
    }

    fn size_hint(&self) -> (usize, Option<usize>) {
        let rem = self.count - self.idx;
        (rem, Some(rem))
    }
}

impl<T> ExactSizeIterator for FlatVecVecIter<'_, T> {}

// NOTE: To avoid large memory allocations, this is a "cache" that stores all the CSS properties
// found in the DOM. This cache exists on a per-DOM basis, so it scales independent of how many
// nodes are in the DOM.
//
// If each node would carry its own CSS properties, that would unnecessarily consume memory
// because most nodes use the default properties or override only one or two properties.
//
// The cache can compute the property of any node at any given time, given the current node
// state (hover, active, focused, normal). This way we don't have to duplicate the CSS properties
// onto every single node and exchange them when the style changes. Two caches can be appended
// to each other by simply merging their NodeIds.
#[derive(Debug, Default, Clone, PartialEq)]
pub struct CssPropertyCache {
    // number of nodes in the current DOM
    pub node_count: usize,

    // The author stylesheet this cache was last cascaded with. Retained so nodes
    // inserted at runtime can be re-styled (`StyledDom::restyle_retained`) — the
    // cascade runs once at creation, and without the rules an inserted node could
    // only ever receive UA defaults + inheritance, never its author CSS.
    // (This struct lives behind `CssPropertyCachePtr`, so the field is invisible
    // to the C ABI.)
    pub retained_author_css: Css,

    // properties that were overridden in callbacks (not specific to any node state)
    pub user_overridden_properties: Vec<Vec<(CssPropertyType, CssProperty)>>,

    // non-default CSS properties that were cascaded from the parent,
    // unified across all pseudo-states (Normal, Hover, Active, Focus, Dragging, DragOver).
    // Stored in a flat cache-friendly layout after sort_and_flatten().
    pub cascaded_props: FlatVecVec<StatefulCssProperty>,

    // non-default CSS properties that were set via a CSS file,
    // unified across all pseudo-states.
    pub css_props: FlatVecVec<StatefulCssProperty>,

    // Pre-resolved inherited properties (sorted Vec per node, keyed by CssPropertyType)
    pub computed_values: Vec<Vec<(CssPropertyType, CssPropertyWithOrigin)>>,

    // Compact layout cache: three-tier numeric encoding for O(1) layout lookups.
    // Built once after restyle + apply_ua_css + compute_inherited_values.
    // Non-compact properties (background, shadow, transform) use get_property_slow().
    pub compact_cache: Option<azul_css::compact_cache::CompactLayoutCache>,

    // Global CSS properties from `*` rules — shared across all nodes.
    // Applied during build_compact_cache_with_inheritance instead of being
    // cloned into each node's css_props (saves 50K×N clones).
    pub global_css_props: Vec<CssProperty>,

    /// Per-node resolved font-size, in pixels, for the `Normal`
    /// pseudo-state. Populated lazily on first call to
    /// [`crate::styled_dom::StyledDom::resolved_font_size_px`] via a
    /// single bottom-up DOM walk; subsequent reads are O(1) Vec
    /// index by `NodeId::index()`.
    ///
    /// Motivation: `get_font_size` is called ~730× per node per
    /// layout pass (see `AZ_PROP_COUNT=1` report — 329 629
    /// cascade walks on excel.html alone). Each resolution
    /// recursively reads the parent's font-size (for `em`) plus
    /// the root's font-size (for `rem`), multiplying the walk
    /// count. Caching the pre-resolved pixel value collapses that
    /// to a single `Vec<f32>` indexed lookup.
    pub resolved_font_sizes_px: crate::sync::OnceLock<Vec<f32>>,
}

/// Heap-size breakdown of a `CssPropertyCache`, produced by
/// [`CssPropertyCache::memory_breakdown`]. All values in bytes.
///
/// Primarily a diagnostic — the numbers are capacity-based and
/// don't chase into property-variant payloads (e.g. the `Vec`
/// inside a `FontFamily(...)`). Intended for "which subfield is
/// eating RSS" triage, not for precise accounting.
#[derive(Debug, Clone, Copy, Default)]
pub struct CssPropertyCacheBreakdown {
    pub node_count: usize,
    pub cascaded_props_bytes: usize,
    pub css_props_bytes: usize,
    pub computed_values_bytes: usize,
    pub user_overridden_bytes: usize,
    pub global_css_props_bytes: usize,
    pub compact_cache_bytes: usize,
    pub resolved_font_sizes_bytes: usize,
}

impl CssPropertyCacheBreakdown {
    /// Sum of all subfields.
    #[must_use] pub const fn total_bytes(&self) -> usize {
        self.cascaded_props_bytes
            + self.css_props_bytes
            + self.computed_values_bytes
            + self.user_overridden_bytes
            + self.global_css_props_bytes
            + self.compact_cache_bytes
            + self.resolved_font_sizes_bytes
    }
}

impl CssPropertyCache {
    /// Approximate heap bytes retained by this cache, broken out by
    /// subfield. Used by `StyledDom::memory_breakdown` + the
    /// `AZ_MEM_BREAKDOWN=1` reporter. Sums capacity × element size
    /// for each Vec and adds a coarse allowance for the inner Vec
    /// headers inside `computed_values`.
    ///
    /// This is a measurement helper, not a tight bound — it doesn't
    /// chase into the `CssProperty` enum variants that carry their
    /// own `Vec`/`String` allocations (notably `FontFamily` →
    /// `StyleFontFamilyVec` → `Vec<StyleFontFamily>`), so the real
    /// heap footprint for a property-rich DOM can be 2-3× these
    /// numbers. Still useful for spotting gross duplication between
    /// the pre-compact and compact caches.
    pub fn memory_breakdown(&self) -> CssPropertyCacheBreakdown {
        let stateful_sz = size_of::<StatefulCssProperty>();
        let computed_entry_sz =
            size_of::<(CssPropertyType, CssPropertyWithOrigin)>();
        let outer_vec_sz = size_of::<Vec<(CssPropertyType, CssPropertyWithOrigin)>>();

        let cascaded_bytes = self.cascaded_props.heap_bytes(stateful_sz);
        let css_bytes = self.css_props.heap_bytes(stateful_sz);

        let mut computed_bytes = self.computed_values.capacity() * outer_vec_sz;
        for v in &self.computed_values {
            computed_bytes += v.capacity() * computed_entry_sz;
        }

        let user_overridden_bytes = {
            let mut b = self.user_overridden_properties.capacity() * outer_vec_sz;
            for v in &self.user_overridden_properties {
                b += v.capacity()
                    * size_of::<(CssPropertyType, CssProperty)>();
            }
            b
        };

        let global_bytes = self.global_css_props.capacity()
            * size_of::<CssProperty>();

        let compact_bytes = self
            .compact_cache
            .as_ref()
            .map_or(0, |c| {
                c.tier1_enums.capacity() * 8
                    + c.tier2_dims.capacity() * 68
                    + c.tier2_cold.capacity() * 28
                    + c.tier2b_text.capacity() * 24
                    + c.prev_font_hashes.capacity() * 8
                    + c.font_dirty_nodes.capacity() * 8
            });

        let resolved_font_sizes_bytes = self
            .resolved_font_sizes_px
            .get()
            .map_or(0, |v| v.capacity() * size_of::<f32>());

        CssPropertyCacheBreakdown {
            node_count: self.node_count,
            cascaded_props_bytes: cascaded_bytes,
            css_props_bytes: css_bytes,
            computed_values_bytes: computed_bytes,
            user_overridden_bytes,
            global_css_props_bytes: global_bytes,
            compact_cache_bytes: compact_bytes,
            resolved_font_sizes_bytes,
        }
    }

    /// Drop Normal-state properties that have compact encodings from
    /// `css_props` and `cascaded_props`. After `build_compact_cache_with_inheritance`,
    /// these are redundant — the compact cache is the source of truth for layout.
    /// Non-Normal entries (hover/active/focus) and non-compact properties
    /// (background, box-shadow, transform, etc.) are kept for `get_property_slow`.
    pub fn prune_compact_normal_props(&mut self) {
        use azul_css::dynamic_selector::PseudoStateType;

        #[cfg(feature = "std")]
        {
        static PRUNE_DBG: std::sync::OnceLock<bool> = std::sync::OnceLock::new();
        let dbg = *PRUNE_DBG.get_or_init(crate::profile::memory_enabled);
        if dbg {
            let mut normal_compact = 0usize;
            let mut normal_noncompact = 0usize;
            let mut nonnormal = 0usize;
            for i in 0..self.css_props.len() {
                for p in self.css_props.get_slice(i) {
                    if p.state != PseudoStateType::Normal {
                        nonnormal += 1;
                    } else if p.prop_type.has_compact_encoding() {
                        normal_compact += 1;
                    } else {
                        normal_noncompact += 1;
                    }
                }
            }
            let ssp_sz = size_of::<StatefulCssProperty>();
            let mut casc_normal_compact = 0usize;
            let mut casc_total = 0usize;
            for i in 0..self.cascaded_props.len() {
                for p in self.cascaded_props.get_slice(i) {
                    casc_total += 1;
                    if p.state == PseudoStateType::Normal && p.prop_type.has_compact_encoding() {
                        casc_normal_compact += 1;
                    }
                }
            }
            eprintln!("[PRUNE] css_props: norm+compact={normal_compact} norm+other={normal_noncompact} nonnorm={nonnormal} SSP={ssp_sz}B | cascaded: total={casc_total} norm+compact={casc_normal_compact}");
        }
        }

        // The compact cache stores SENTINEL for pixel-valued properties whose inner
        // value is Exact with a non-px metric (vh, vw, %, em, rem, calc(), ...).
        // Those need the slow `css_props` walk at layout time because the compact
        // cache has nothing usable. We must keep them here or the slow path falls
        // back to UA CSS and silently clobbers the author's rule.
        let keep = |p: &StatefulCssProperty| -> bool {
            if p.state != PseudoStateType::Normal {
                return true;
            }
            if !p.prop_type.has_compact_encoding() {
                return true;
            }
            // Compact-encoded AND Normal: drop only if the compact cache fully
            // captured the value (px metric, or Auto/Initial/Inherit/None).
            if property_needs_slow_path_after_compact(&p.property) {
                return true;
            }
            false
        };
        // DO NOT prune css_props: regenerate_layout calls
        // recompute_inheritance_and_compact_cache() every frame, which REBUILDS the
        // compact cache from css_props (build_compact_cache_with_inheritance reads
        // css_props in its per-node Step 3). If we drop compact-encoded Normal props
        // here, that rebuild reads pruned css_props and resets those props to their
        // CSS-initial value — e.g. white-space:pre-wrap on a node regressed to Normal
        // on the 2nd (recompute) build, collapsing \n in pre-wrap text into one line
        // (#8, intermittently — depends on whether the recompute ran). The doc's
        // premise ("the compact cache is the source of truth", implying permanence)
        // is false given that per-frame recompute. cascaded_props is NOT read by the
        // rebuild (Step 1 inherits from the parent's COMPACT value, not cascaded_props),
        // so pruning it remains safe. TODO: re-enable css_props pruning once recompute
        // becomes incremental (preserve directly-set compact values instead of rebuilding).
        if !self.cascaded_props.is_flattened() {
            self.cascaded_props.sort_each_and_flatten(|p| (p.state, p.prop_type));
        }
        self.cascaded_props.retain(keep);
    }

    /// Look up a CSS property for a specific pseudo-state in a stateful property vec.
    /// Requires the vec to be sorted by (state, `prop_type`).
    #[inline]
    // prop_cache threads &NodeId/&CssPropertyType uniformly through its hot cascade
    // lookup API (40+ such params); flipping only clippy's few flags to by-value
    // would force ref/deref juggling at every boundary with the by-ref majority,
    // for no measurable hot-path gain — keep the uniform by-ref convention.
    #[allow(clippy::trivially_copy_pass_by_ref)]
    fn find_in_stateful<'a>(
        props: &'a [StatefulCssProperty],
        state: azul_css::dynamic_selector::PseudoStateType,
        prop_type: &CssPropertyType,
    ) -> Option<&'a CssProperty> {
        let key = (state, *prop_type);
        props.binary_search_by_key(&key, |p| (p.state, p.prop_type))
            .ok()
            .map(|idx| &props[idx].property)
    }

    /// Check if any properties exist for a specific pseudo-state in a stateful property vec.
    /// Requires the vec to be sorted by (state, `prop_type`).
    #[inline]
    fn has_state_props(
        props: &[StatefulCssProperty],
        state: azul_css::dynamic_selector::PseudoStateType,
    ) -> bool {
        // All entries with the same state are contiguous. Use partition_point
        // to find the first entry >= state, then check if it matches.
        let i = props.partition_point(|p| p.state < state);
        i < props.len() && props[i].state == state
    }

    /// Collect all property types for a specific pseudo-state.
    pub(crate) fn prop_types_for_state(
        props: &[StatefulCssProperty],
        state: azul_css::dynamic_selector::PseudoStateType,
    ) -> impl Iterator<Item = &CssPropertyType> + '_ {
        props.iter().filter(move |p| p.state == state).map(|p| &p.prop_type)
    }
}

/// Returns true if `prop`'s value cannot be fully represented in the compact
/// cache and therefore needs to survive `prune_compact_normal_props` so the
/// slow `css_props` walk can still find it at layout time.
///
/// Pixel-valued properties (margin, padding, width, height, ...) are the only
/// case: `Exact(pv)` with `pv.metric != Px` (vh, vw, %, em, rem, ...) encodes
/// to the compact cache's SENTINEL slot, which loses the value. All other
/// compact-encoded types (tier1 enums, colors, hashes, etc.) always round-trip
/// through the compact encoding.
fn property_needs_slow_path_after_compact(prop: &CssProperty) -> bool {
    use azul_css::css::CssPropertyValue;
    use azul_css::props::{
        basic::length::SizeMetric,
        layout::{
            dimensions::{LayoutHeight, LayoutWidth},
            flex::LayoutFlexBasis,
        },
    };

    // `inner: PixelValue` wrapper types — check metric directly.
    macro_rules! check_plain {
        ($v:expr) => {{
            if let CssPropertyValue::Exact(ref inner) = $v {
                return inner.inner.metric != SizeMetric::Px;
            }
            false
        }};
    }

    match prop {
        // LayoutWidth / LayoutHeight: enum with `Px(PixelValue)` variant.
        // Non-pixel variants (Auto / MinContent / MaxContent / FitContent / Calc)
        // are already handled by the tier1 fast path or don't exist as i16 dims.
        CssProperty::Width(v) => {
            if let CssPropertyValue::Exact(LayoutWidth::Px(pv)) = v {
                return pv.metric != SizeMetric::Px;
            }
            false
        }
        CssProperty::Height(v) => {
            if let CssPropertyValue::Exact(LayoutHeight::Px(pv)) = v {
                return pv.metric != SizeMetric::Px;
            }
            false
        }

        // LayoutFlexBasis: enum with `Exact(PixelValue)` variant.
        CssProperty::FlexBasis(v) => {
            if let CssPropertyValue::Exact(LayoutFlexBasis::Exact(pv)) = v {
                return pv.metric != SizeMetric::Px;
            }
            false
        }

        // `inner: PixelValue` wrappers
        CssProperty::MinWidth(v) => check_plain!(v),
        CssProperty::MaxWidth(v) => check_plain!(v),
        CssProperty::MinHeight(v) => check_plain!(v),
        CssProperty::MaxHeight(v) => check_plain!(v),
        CssProperty::FontSize(v) => check_plain!(v),
        CssProperty::PaddingTop(v) => check_plain!(v),
        CssProperty::PaddingRight(v) => check_plain!(v),
        CssProperty::PaddingBottom(v) => check_plain!(v),
        CssProperty::PaddingLeft(v) => check_plain!(v),
        CssProperty::MarginTop(v) => check_plain!(v),
        CssProperty::MarginRight(v) => check_plain!(v),
        CssProperty::MarginBottom(v) => check_plain!(v),
        CssProperty::MarginLeft(v) => check_plain!(v),
        CssProperty::BorderTopWidth(v) => check_plain!(v),
        CssProperty::BorderRightWidth(v) => check_plain!(v),
        CssProperty::BorderBottomWidth(v) => check_plain!(v),
        CssProperty::BorderLeftWidth(v) => check_plain!(v),
        CssProperty::Top(v) => check_plain!(v),
        CssProperty::Right(v) => check_plain!(v),
        CssProperty::Bottom(v) => check_plain!(v),
        CssProperty::Left(v) => check_plain!(v),
        CssProperty::ColumnGap(v) => check_plain!(v),
        CssProperty::RowGap(v) => check_plain!(v),
        CssProperty::LetterSpacing(v) => check_plain!(v),
        CssProperty::WordSpacing(v) => check_plain!(v),
        CssProperty::TextIndent(v) => check_plain!(v),
        CssProperty::TabSize(v) => check_plain!(v),

        // All other compact-encoded types round-trip through the compact cache.
        _ => false,
    }
}

/// Clone a `CssProperty` WITHOUT going through its derived `Clone`. The derived clone
/// is a ~179-arm `match self { V(x) => V(x.clone()) }` that LLVM lowers to an indirect
/// HALFWORD jump table (`ldrh`-indexed). The web (remill→wasm) backend mis-lifts that
/// table, so for HEAP/Vec-bearing variants (gradients, font-family, shadows, filters,
/// transforms) the mis-dispatched clone reads wrong-sized data and the cascade traps
/// with "memory access out of bounds" (restyle → inherit → clone). Here every
/// heap-bearing variant is dispatched via single-variant `if let` — a direct
/// discriminant compare, NO jump table — and each inner `v.clone()` is the value
/// type's own clone, which lifts correctly. POD variants fall through to the derived
/// clone: correct on native, and harmless on web (a mis-dispatched discriminant 0 is
/// `CaretColor`, a `Copy` value with no heap pointer to deref). On native this function
/// is byte-for-byte equivalent to `p.clone()`.
/// Inheritable properties whose value must be inherited as the parent's already
/// *resolved* value, NOT propagated as a raw declaration through `cascaded_props`.
///
/// `font-size` is the case: a relative parent value (`1.5em`) propagated raw
/// would be re-resolved against the already-resolved parent at every descendant
/// (multiplicative error: 30px -> 45px -> 67.5px down a chain), and a parent
/// whose own `cascaded` font-size is the *grandparent's* absolute value would
/// skip the parent's own size entirely. Both consuming paths already inherit
/// font-size correctly from the parent's resolved value — `inherit_from_parent`
/// for `computed_values`, and the parent's resolved compact slot in
/// `build_compact_cache_with_inheritance` — so font-size must not ride the raw
/// propagation at all.
fn is_resolved_parent_inherited(prop_type: CssPropertyType) -> bool {
    prop_type == CssPropertyType::FontSize
}

fn clone_inheritable_property(
    p: &CssProperty,
) -> CssProperty {
    use azul_css::props::property::CssProperty;
    if let CssProperty::FontFamily(v) = p { return CssProperty::FontFamily(v.clone()); }
    if let CssProperty::BackgroundContent(v) = p { return CssProperty::BackgroundContent(v.clone()); }
    if let CssProperty::BackgroundPosition(v) = p { return CssProperty::BackgroundPosition(v.clone()); }
    if let CssProperty::BackgroundSize(v) = p { return CssProperty::BackgroundSize(v.clone()); }
    if let CssProperty::BackgroundRepeat(v) = p { return CssProperty::BackgroundRepeat(v.clone()); }
    if let CssProperty::BoxShadowLeft(v) = p { return CssProperty::BoxShadowLeft(v.clone()); }
    if let CssProperty::BoxShadowRight(v) = p { return CssProperty::BoxShadowRight(v.clone()); }
    if let CssProperty::BoxShadowTop(v) = p { return CssProperty::BoxShadowTop(v.clone()); }
    if let CssProperty::BoxShadowBottom(v) = p { return CssProperty::BoxShadowBottom(v.clone()); }
    if let CssProperty::TextShadow(v) = p { return CssProperty::TextShadow(v.clone()); }
    if let CssProperty::ScrollbarTrack(v) = p { return CssProperty::ScrollbarTrack(v.clone()); }
    if let CssProperty::ScrollbarThumb(v) = p { return CssProperty::ScrollbarThumb(v.clone()); }
    if let CssProperty::ScrollbarButton(v) = p { return CssProperty::ScrollbarButton(v.clone()); }
    if let CssProperty::ScrollbarCorner(v) = p { return CssProperty::ScrollbarCorner(v.clone()); }
    if let CssProperty::ScrollbarResizer(v) = p { return CssProperty::ScrollbarResizer(v.clone()); }
    if let CssProperty::Transform(v) = p { return CssProperty::Transform(v.clone()); }
    if let CssProperty::Filter(v) = p { return CssProperty::Filter(v.clone()); }
    if let CssProperty::BackdropFilter(v) = p { return CssProperty::BackdropFilter(v.clone()); }
    if let CssProperty::Content(v) = p { return CssProperty::Content(v.clone()); }
    if let CssProperty::HyphenationLanguage(v) = p { return CssProperty::HyphenationLanguage(v.clone()); }
    if let CssProperty::Cursor(v) = p { return CssProperty::Cursor(*v); }
    p.clone()
}

impl CssPropertyCache {
    /// Match CSS selectors to nodes and populate `css_props`.
    /// Returns tag IDs for hit-testing. If `compact_cache` is available,
    /// uses it for fast display/overflow checks; otherwise falls back to slow path.
    #[must_use]
    #[allow(clippy::too_many_lines, clippy::cognitive_complexity)] // large but cohesive: single-purpose parser/builder/dispatch (one branch per input variant)
    pub fn restyle(
        &mut self,
        css: &mut Css,
        node_data: &NodeDataContainerRef<'_, NodeData>,
        node_hierarchy: &NodeHierarchyItemVec,
        non_leaf_nodes: &ParentWithNodeDepthVec,
        html_tree: &NodeDataContainerRef<'_, CascadeInfo>,
    ) -> Vec<TagIdToNodeIdMapping> {
        use azul_css::{
            css::{CssDeclaration, CssPathPseudoSelector::{Hover, Active, Focus, Dragging, DragOver}, CssPathSelector, CssRuleBlock},
            dynamic_selector::{DynamicSelector, PseudoStateType},
            props::layout::LayoutDisplay,
        };

        let css_is_empty = css.is_empty();

        if !css_is_empty {
            css.sort_by_specificity();

            // Separate CSS rules into "global only" (just `*`) vs "has specific selector".
            // Global-only rules apply to ALL nodes — push directly into css_props
            // without per-node selector matching (avoids m×n for these rules).
            // Specific rules still go through matches_html_element per-node.
            let mut global_only_rules: Vec<&CssRuleBlock> = Vec::new();
            let mut specific_rules: Vec<&CssRuleBlock> = Vec::new();

            for rule in css.rules() {
                let selectors = rule.path.selectors.as_ref();
                let is_global_only = selectors.len() == 1
                    && matches!(selectors.first(), Some(CssPathSelector::Global));
                if is_global_only {
                    global_only_rules.push(rule);
                } else {
                    specific_rules.push(rule);
                }
            }

            // Re-enter build phase before repopulating. restyle() is not
            // single-shot: StyledDom::create runs one restyle internally, and building
            // the compact cache flattens these vecs — so on a later restyle both are in
            // read phase, where the old reset `build_iter_mut().clear()` silently
            // iterated ZERO entries (flatten empties `build`). The push_to / build_mut
            // below then indexed an emptied Vec and panicked.
            //
            // css_props is rebuilt from scratch each restyle (repopulated below,
            // flattened at the end), so replace it with a fresh build-phase vec.
            // cascaded_props must PRESERVE its contents — restyle READS parents'
            // cascaded slices to inherit, and it accumulates across restyles with
            // or_insert dedup — so un-flatten it in place instead of clearing.
            let node_count = self.css_props.len();
            self.css_props = FlatVecVec::new(node_count);
            self.cascaded_props.ensure_build_phase();

            // Collect global-only rule declarations ONCE (not per-node).
            // These are stored in self.global_css_props and applied during
            // build_compact_cache_with_inheritance for each node, avoiding
            // 50K × N clones into per-node css_props Vecs.
            self.global_css_props.clear();
            for rule in &global_only_rules {
                if crate::style::rule_ends_with(&rule.path, None) {
                    for d in &rule.declarations {
                        if let CssDeclaration::Static(s) = d {
                            self.global_css_props.push(s.clone());
                        }
                    }
                }
            }

            // Phase 2: Match specific rules per-node (only non-global rules)
            if !specific_rules.is_empty() {

            // Per-node "which declarations match" lists are built as
            // `(rule_idx, decl_idx)` pairs — 4 bytes per entry instead of
            // cloning a 140-byte `CssProperty`. The clone only happens at
            // the final push_to step, so the transient peak is ~35× smaller.
            //
            // rule_idx indexes into `specific_rules` (Vec<&CssRuleBlock>),
            // decl_idx indexes into `rule.declarations.as_slice()`. Both
            // fit in u16 since real stylesheets have far fewer than 65k
            // rules and declarations per rule.
            macro_rules! filter_rules {($expected_pseudo_selector:expr, $node_id:expr) => {{
                let mut out: Vec<(u16, u16)> = Vec::new();
                for (rule_idx, rule_block) in specific_rules.iter().enumerate() {
                    if !crate::style::rule_ends_with(&rule_block.path, $expected_pseudo_selector) {
                        continue;
                    }
                    if !crate::style::matches_html_element(
                        &rule_block.path,
                        $node_id,
                        &node_hierarchy.as_container(),
                        &node_data,
                        &html_tree,
                        $expected_pseudo_selector,
                    ) {
                        continue;
                    }
                    for (decl_idx, decl) in rule_block.declarations.as_slice().iter().enumerate() {
                        if matches!(decl, CssDeclaration::Static(_)) {
                            out.push((u16::try_from(rule_idx).unwrap_or(u16::MAX), u16::try_from(decl_idx).unwrap_or(u16::MAX)));
                        }
                    }
                }
                out
            }};}

            // Pre-check which pseudo-states have any matching rules at all.
            // This avoids iterating 50K nodes for pseudo-states with zero rules
            // (common: most stylesheets have no :hover/:focus/:active rules).
            let has_normal = specific_rules.iter().any(|r| crate::style::rule_ends_with(&r.path, None));
            let has_hover = specific_rules.iter().any(|r| crate::style::rule_ends_with(&r.path, Some(Hover)));
            let has_active = specific_rules.iter().any(|r| crate::style::rule_ends_with(&r.path, Some(Active)));
            let has_focus = specific_rules.iter().any(|r| crate::style::rule_ends_with(&r.path, Some(Focus)));
            let has_dragging = specific_rules.iter().any(|r| crate::style::rule_ends_with(&r.path, Some(Dragging)));
            let has_drag_over = specific_rules.iter().any(|r| crate::style::rule_ends_with(&r.path, Some(DragOver)));

            macro_rules! collect_and_assign {
                ($pseudo:expr, $state:expr, $has_any:expr) => {
                    if $has_any {
                        let indices: NodeDataContainer<(NodeId, Vec<(u16, u16)>)> = node_data
                            .transform_nodeid_optional(|node_id| {
                                let r = filter_rules!($pseudo, node_id);
                                if r.is_empty() { None } else { Some((node_id, r)) }
                            });
                        for (n, pairs) in indices.internal.into_iter() {
                            for (rule_idx, decl_idx) in pairs {
                                let decl = &specific_rules[rule_idx as usize]
                                    .declarations
                                    .as_slice()[decl_idx as usize];
                                if let CssDeclaration::Static(prop) = decl {
                                    self.css_props.push_to(n.index(), StatefulCssProperty {
                                        state: $state,
                                        prop_type: prop.get_type(),
                                        property: prop.clone(),
                                    });
                                }
                            }
                        }
                    }
                };
            }

            collect_and_assign!(None, PseudoStateType::Normal, has_normal);
            collect_and_assign!(Some(Hover), PseudoStateType::Hover, has_hover);
            collect_and_assign!(Some(Active), PseudoStateType::Active, has_active);
            collect_and_assign!(Some(Focus), PseudoStateType::Focus, has_focus);
            collect_and_assign!(Some(Dragging), PseudoStateType::Dragging, has_dragging);
            collect_and_assign!(Some(DragOver), PseudoStateType::DragOver, has_drag_over);

            } // end if !specific_rules.is_empty()
        }

        // Inheritance: Inherit all values of the parent to the children, but
        // only if the property is inheritable and isn't yet set
        for ParentWithNodeDepth { depth: _, node_id } in non_leaf_nodes {
            let Some(parent_id) = node_id.into_crate_internal() else {
                continue;
            };

            let all_states = [
                PseudoStateType::Normal,
                PseudoStateType::Hover,
                PseudoStateType::Active,
                PseudoStateType::Focus,
                PseudoStateType::Dragging,
                PseudoStateType::DragOver,
            ];

            for &state in &all_states {
                // 1. Inherit inline CSS properties from parent for this pseudo-state
                let parent_inheritable_inline: Vec<(CssPropertyType, CssProperty)> = node_data[parent_id]
                    .style
                    .iter_inline_properties()
                    .filter(|(_prop, conds)| {
                        let conditions = conds.as_slice();
                        if conditions.is_empty() {
                            state == PseudoStateType::Normal
                        } else {
                            conditions.iter().all(|c| {
                                matches!(c, DynamicSelector::PseudoState(s) if *s == state)
                            })
                        }
                    })
                    .map(|(prop, _)| prop)
                    .filter(|prop| prop.get_type().is_inheritable() && !is_resolved_parent_inherited(prop.get_type()))
                    .map(|p| (p.get_type(), clone_inheritable_property(p)))
                    .collect();

                // 2. Inherit CSS stylesheet properties from parent for this pseudo-state
                let parent_inheritable_css: Vec<(CssPropertyType, CssProperty)> = if css_is_empty {
                    Vec::new()
                } else {
                    self.css_props.get_slice(parent_id.index())
                        .iter()
                        .filter(|p| p.state == state && p.prop_type.is_inheritable() && !is_resolved_parent_inherited(p.prop_type))
                        .map(|p| (p.prop_type, clone_inheritable_property(&p.property)))
                        .collect()
                };

                // 3. Inherit cascaded properties from parent for this pseudo-state
                let parent_inheritable_cascaded: Vec<(CssPropertyType, CssProperty)> =
                    self.cascaded_props.get_slice(parent_id.index())
                        .iter()
                        .filter(|p| p.state == state && p.prop_type.is_inheritable() && !is_resolved_parent_inherited(p.prop_type))
                        .map(|p| (p.prop_type, clone_inheritable_property(&p.property)))
                        .collect();

                // Combine all inheritable props (inline first = strongest, cascaded last)
                // Only insert if child doesn't already have that (state, prop_type) combo
                if parent_inheritable_inline.is_empty()
                    && parent_inheritable_css.is_empty()
                    && parent_inheritable_cascaded.is_empty()
                {
                    continue;
                }

                for child_id in parent_id.az_children(&node_hierarchy.as_container()) {
                    let child_vec = self.cascaded_props.build_mut(child_id.index());
                    for (prop_type, prop_value) in parent_inheritable_inline
                        .iter()
                        .chain(parent_inheritable_css.iter())
                        .chain(parent_inheritable_cascaded.iter())
                    {
                        // or_insert: only insert if child doesn't already have this (state, prop_type)
                        if !child_vec.iter().any(|p| p.state == state && p.prop_type == *prop_type) {
                            child_vec.push(StatefulCssProperty {
                                state,
                                prop_type: *prop_type,
                                property: prop_value.clone(),
                            });
                        }
                    }
                }
            }
        }

        // Sort css_props by (state, prop_type) for binary search lookups,
        // then flatten into contiguous memory for cache-friendly reads.
        self.css_props.sort_each_and_flatten(|p| (p.state, p.prop_type));

        // Restyling can change font-size properties; the memoized resolved font
        // sizes are now stale and must be recomputed on next access.
        self.invalidate_resolved_font_sizes();

        self.generate_tag_ids(node_data, node_hierarchy)
    }

    /// Generate hit-test tag IDs for nodes that need event handling.
    /// Uses compact cache (if available) for fast display/overflow reads.
    /// Can be called separately after `build_compact_cache_with_inheritance`.
    pub fn generate_tag_ids(
        &self,
        node_data: &NodeDataContainerRef<'_, NodeData>,
        node_hierarchy: &NodeHierarchyItemVec,
    ) -> Vec<TagIdToNodeIdMapping> {

        // Tag ID generation: determine which nodes need hit-test tags for
        // hover/click/scroll events. Uses compact cache for display/overflow
        // checks instead of get_property_slow (which searches 6 data structures).
        use azul_css::compact_cache::{
            DISPLAY_SHIFT, DISPLAY_MASK,
            OVERFLOW_X_SHIFT, OVERFLOW_Y_SHIFT, OVERFLOW_MASK,
        };

        let compact_cache = self.compact_cache.as_ref();
        let node_data_container = &node_data.internal;

        let tag_ids = node_data
            .internal
            .iter()
            .enumerate()
            .filter_map(|(node_idx, node_data)| {
                let node_id = NodeId::new(node_idx);

                let should_auto_insert_tabindex = node_data
                    .get_callbacks()
                    .iter()
                    .any(|cb| cb.event.is_focus_callback());

                let tab_index = node_data.get_tab_index().map_or(if should_auto_insert_tabindex {
                            Some(TabIndex::Auto)
                        } else {
                            None
                        }, Some);

                let mut need_tag = false;

                // Single-pass guard block: each check `break`s out early once it
                // decides `need_tag`. Labeled block (not `loop`) makes the
                // never-iterating control flow explicit (clippy::never_loop).
                'compute_need_tag: {
                    // display:none check — read directly from compact tier1 (fast u64 read)
                    if let Some(cc) = compact_cache.as_ref() {
                        let t1 = cc.tier1_enums[node_idx];
                        let display_val = ((t1 >> DISPLAY_SHIFT) & DISPLAY_MASK) as u8;
                        if display_val == 4 { break 'compute_need_tag; } // 4 = LayoutDisplay::None (new encoding)
                    }

                    if node_data.has_context_menu() || node_data.get_context_menu().is_some() {
                        need_tag = true; break 'compute_need_tag;
                    }
                    if tab_index.is_some() { need_tag = true; break 'compute_need_tag; }

                    // Pseudo-state property checks (hover/active/focus/dragging/drag-over)
                    {
                        use azul_css::dynamic_selector::{DynamicSelector, PseudoStateType};
                        let has_pseudo = |state: PseudoStateType| -> bool {
                            node_data.style.iter_inline_properties().any(|(_p, conds)| {
                                conds.as_slice().iter().any(|c|
                                    matches!(c, DynamicSelector::PseudoState(s) if *s == state)
                                )
                            }) || Self::has_state_props(self.css_props.get_slice(node_idx), state)
                        };

                        if has_pseudo(PseudoStateType::Hover)
                            || has_pseudo(PseudoStateType::Active)
                            || has_pseudo(PseudoStateType::Focus)
                            || has_pseudo(PseudoStateType::Dragging)
                            || has_pseudo(PseudoStateType::DragOver)
                        {
                            need_tag = true; break 'compute_need_tag;
                        }
                    }

                    // Non-window callbacks
                    let has_non_window_cb = !node_data.get_callbacks().is_empty()
                        && !node_data.get_callbacks().iter().all(|cb| cb.event.is_window_callback());
                    if has_non_window_cb { need_tag = true; break 'compute_need_tag; }

                    // Cursor check — read from cached css_props or inline style.
                    if self.css_props.get_slice(node_idx).iter().any(|p|
                        p.state == azul_css::dynamic_selector::PseudoStateType::Normal
                        && p.prop_type == CssPropertyType::Cursor
                    ) || node_data.style.iter_inline_properties().any(|(p, _)|
                        p.get_type() == CssPropertyType::Cursor
                    ) {
                        need_tag = true; break 'compute_need_tag;
                    }

                    // Overflow scroll check — read from compact tier1
                    if let Some(cc) = compact_cache.as_ref() {
                        let t1 = cc.tier1_enums[node_idx];
                        let ox = ((t1 >> OVERFLOW_X_SHIFT) & OVERFLOW_MASK) as u8;
                        let oy = ((t1 >> OVERFLOW_Y_SHIFT) & OVERFLOW_MASK) as u8;
                        // 2 = Scroll, 3 = Auto in layout_overflow_to_u8 (new encoding)
                        if ox == 2 || ox == 3 || oy == 2 || oy == 3 {
                            need_tag = true; break 'compute_need_tag;
                        }
                    }

                    // Selectable text check
                    {
                        use crate::dom::NodeType;
                        let hier = node_hierarchy.as_container()[node_id];
                        let mut has_text = false;
                        if let Some(first_child) = hier.first_child_id(node_id) {
                            let mut child_id = Some(first_child);
                            while let Some(cid) = child_id {
                                if matches!(node_data_container[cid.index()].get_node_type(), NodeType::Text(_)) {
                                    has_text = true; break;
                                }
                                child_id = node_hierarchy.as_container()[cid].next_sibling_id();
                            }
                        }
                        if has_text { need_tag = true; break 'compute_need_tag; }
                    }

                    break 'compute_need_tag;
                }

                if need_tag {
                    Some(TagIdToNodeIdMapping {
                        tag_id: TagId::from_crate_internal(TagId::unique()),
                        node_id: NodeHierarchyItemId::from_crate_internal(Some(node_id)),
                        tab_index: tab_index.into(),
                    })
                } else {
                    None
                }
            })
            .collect::<Vec<_>>();

        tag_ids
    }

    #[allow(clippy::too_many_lines, clippy::cognitive_complexity)] // large but cohesive: single-purpose parser/builder/dispatch (one branch per input variant)
    pub fn get_computed_css_style_string(
        &self,
        node_data: &NodeData,
        node_id: &NodeId,
        node_state: &StyledNodeState,
    ) -> String {
        let mut s = String::new();
        if let Some(p) = self.get_background_content(node_data, node_id, node_state) {
            let _ = write!(s,"background: {};", p.get_css_value_fmt());
        }
        if let Some(p) = self.get_background_position(node_data, node_id, node_state) {
            let _ = write!(s,"background-position: {};", p.get_css_value_fmt());
        }
        if let Some(p) = self.get_background_size(node_data, node_id, node_state) {
            let _ = write!(s,"background-size: {};", p.get_css_value_fmt());
        }
        if let Some(p) = self.get_background_repeat(node_data, node_id, node_state) {
            let _ = write!(s,"background-repeat: {};", p.get_css_value_fmt());
        }
        if let Some(p) = self.get_font_size(node_data, node_id, node_state) {
            let _ = write!(s,"font-size: {};", p.get_css_value_fmt());
        }
        if let Some(p) = self.get_font_family(node_data, node_id, node_state) {
            let _ = write!(s,"font-family: {};", p.get_css_value_fmt());
        }
        if let Some(p) = self.get_text_color(node_data, node_id, node_state) {
            let _ = write!(s,"color: {};", p.get_css_value_fmt());
        }
        if let Some(p) = self.get_text_align(node_data, node_id, node_state) {
            let _ = write!(s,"text-align: {};", p.get_css_value_fmt());
        }
        if let Some(p) = self.get_line_height(node_data, node_id, node_state) {
            let _ = write!(s,"line-height: {};", p.get_css_value_fmt());
        }
        if let Some(p) = self.get_letter_spacing(node_data, node_id, node_state) {
            let _ = write!(s,"letter-spacing: {};", p.get_css_value_fmt());
        }
        if let Some(p) = self.get_word_spacing(node_data, node_id, node_state) {
            let _ = write!(s,"word-spacing: {};", p.get_css_value_fmt());
        }
        if let Some(p) = self.get_tab_size(node_data, node_id, node_state) {
            let _ = write!(s,"tab-size: {};", p.get_css_value_fmt());
        }
        if let Some(p) = self.get_cursor(node_data, node_id, node_state) {
            let _ = write!(s,"cursor: {};", p.get_css_value_fmt());
        }
        if let Some(p) = self.get_box_shadow_left(node_data, node_id, node_state) {
            let _ = write!(s,
                "-azul-box-shadow-left: {};",
                p.get_css_value_fmt()
            );
        }
        if let Some(p) = self.get_box_shadow_right(node_data, node_id, node_state) {
            let _ = write!(s,
                "-azul-box-shadow-right: {};",
                p.get_css_value_fmt()
            );
        }
        if let Some(p) = self.get_box_shadow_top(node_data, node_id, node_state) {
            let _ = write!(s,"-azul-box-shadow-top: {};", p.get_css_value_fmt());
        }
        if let Some(p) = self.get_box_shadow_bottom(node_data, node_id, node_state) {
            let _ = write!(s,
                "-azul-box-shadow-bottom: {};",
                p.get_css_value_fmt()
            );
        }
        if let Some(p) = self.get_border_top_color(node_data, node_id, node_state) {
            let _ = write!(s,"border-top-color: {};", p.get_css_value_fmt());
        }
        if let Some(p) = self.get_border_left_color(node_data, node_id, node_state) {
            let _ = write!(s,"border-left-color: {};", p.get_css_value_fmt());
        }
        if let Some(p) = self.get_border_right_color(node_data, node_id, node_state) {
            let _ = write!(s,"border-right-color: {};", p.get_css_value_fmt());
        }
        if let Some(p) = self.get_border_bottom_color(node_data, node_id, node_state) {
            let _ = write!(s,"border-bottom-color: {};", p.get_css_value_fmt());
        }
        if let Some(p) = self.get_border_top_style(node_data, node_id, node_state) {
            let _ = write!(s,"border-top-style: {};", p.get_css_value_fmt());
        }
        if let Some(p) = self.get_border_left_style(node_data, node_id, node_state) {
            let _ = write!(s,"border-left-style: {};", p.get_css_value_fmt());
        }
        if let Some(p) = self.get_border_right_style(node_data, node_id, node_state) {
            let _ = write!(s,"border-right-style: {};", p.get_css_value_fmt());
        }
        if let Some(p) = self.get_border_bottom_style(node_data, node_id, node_state) {
            let _ = write!(s,"border-bottom-style: {};", p.get_css_value_fmt());
        }
        if let Some(p) = self.get_border_top_left_radius(node_data, node_id, node_state) {
            let _ = write!(s,
                "border-top-left-radius: {};",
                p.get_css_value_fmt()
            );
        }
        if let Some(p) = self.get_border_top_right_radius(node_data, node_id, node_state) {
            let _ = write!(s,
                "border-top-right-radius: {};",
                p.get_css_value_fmt()
            );
        }
        if let Some(p) = self.get_border_bottom_left_radius(node_data, node_id, node_state) {
            let _ = write!(s,
                "border-bottom-left-radius: {};",
                p.get_css_value_fmt()
            );
        }
        if let Some(p) = self.get_border_bottom_right_radius(node_data, node_id, node_state) {
            let _ = write!(s,
                "border-bottom-right-radius: {};",
                p.get_css_value_fmt()
            );
        }
        if let Some(p) = self.get_opacity(node_data, node_id, node_state) {
            let _ = write!(s,"opacity: {};", p.get_css_value_fmt());
        }
        if let Some(p) = self.get_transform(node_data, node_id, node_state) {
            let _ = write!(s,"transform: {};", p.get_css_value_fmt());
        }
        if let Some(p) = self.get_transform_origin(node_data, node_id, node_state) {
            let _ = write!(s,"transform-origin: {};", p.get_css_value_fmt());
        }
        if let Some(p) = self.get_perspective_origin(node_data, node_id, node_state) {
            let _ = write!(s,"perspective-origin: {};", p.get_css_value_fmt());
        }
        if let Some(p) = self.get_backface_visibility(node_data, node_id, node_state) {
            let _ = write!(s,"backface-visibility: {};", p.get_css_value_fmt());
        }
        if let Some(p) = self.get_hyphens(node_data, node_id, node_state) {
            let _ = write!(s,"hyphens: {};", p.get_css_value_fmt());
        }
        if let Some(p) = self.get_direction(node_data, node_id, node_state) {
            let _ = write!(s,"direction: {};", p.get_css_value_fmt());
        }
        if let Some(p) = self.get_unicode_bidi(node_data, node_id, node_state) {
            let _ = write!(s,"unicode-bidi: {};", p.get_css_value_fmt());
        }
        if let Some(p) = self.get_text_box_trim(node_data, node_id, node_state) {
            let _ = write!(s,"text-box-trim: {};", p.get_css_value_fmt());
        }
        if let Some(p) = self.get_text_box_edge(node_data, node_id, node_state) {
            let _ = write!(s,"text-box-edge: {};", p.get_css_value_fmt());
        }
        if let Some(p) = self.get_dominant_baseline(node_data, node_id, node_state) {
            let _ = write!(s,"dominant-baseline: {};", p.get_css_value_fmt());
        }
        if let Some(p) = self.get_alignment_baseline(node_data, node_id, node_state) {
            let _ = write!(s,"alignment-baseline: {};", p.get_css_value_fmt());
        }
        if let Some(p) = self.get_baseline_source(node_data, node_id, node_state) {
            let _ = write!(s,"baseline-source: {};", p.get_css_value_fmt());
        }
        if let Some(p) = self.get_line_fit_edge(node_data, node_id, node_state) {
            let _ = write!(s,"line-fit-edge: {};", p.get_css_value_fmt());
        }
        if let Some(p) = self.get_initial_letter_align(node_data, node_id, node_state) {
            let _ = write!(s,"initial-letter-align: {};", p.get_css_value_fmt());
        }
        if let Some(p) = self.get_initial_letter_wrap(node_data, node_id, node_state) {
            let _ = write!(s,"initial-letter-wrap: {};", p.get_css_value_fmt());
        }
        if let Some(p) = self.get_scrollbar_gutter(node_data, node_id, node_state) {
            let _ = write!(s,"scrollbar-gutter: {};", p.get_css_value_fmt());
        }
        if let Some(p) = self.get_overflow_clip_margin(node_data, node_id, node_state) {
            let _ = write!(s,"overflow-clip-margin: {};", p.get_css_value_fmt());
        }
        if let Some(p) = self.get_clip(node_data, node_id, node_state) {
            let _ = write!(s,"clip: {};", p.get_css_value_fmt());
        }
        if let Some(p) = self.get_white_space(node_data, node_id, node_state) {
            let _ = write!(s,"white-space: {};", p.get_css_value_fmt());
        }
        if let Some(p) = self.get_display(node_data, node_id, node_state) {
            let _ = write!(s,"display: {};", p.get_css_value_fmt());
        }
        if let Some(p) = self.get_float(node_data, node_id, node_state) {
            let _ = write!(s,"float: {};", p.get_css_value_fmt());
        }
        if let Some(p) = self.get_box_sizing(node_data, node_id, node_state) {
            let _ = write!(s,"box-sizing: {};", p.get_css_value_fmt());
        }
        if let Some(p) = self.get_width(node_data, node_id, node_state) {
            let _ = write!(s,"width: {};", p.get_css_value_fmt());
        }
        if let Some(p) = self.get_height(node_data, node_id, node_state) {
            let _ = write!(s,"height: {};", p.get_css_value_fmt());
        }
        if let Some(p) = self.get_min_width(node_data, node_id, node_state) {
            let _ = write!(s,"min-width: {};", p.get_css_value_fmt());
        }
        if let Some(p) = self.get_min_height(node_data, node_id, node_state) {
            let _ = write!(s,"min-height: {};", p.get_css_value_fmt());
        }
        if let Some(p) = self.get_max_width(node_data, node_id, node_state) {
            let _ = write!(s,"max-width: {};", p.get_css_value_fmt());
        }
        if let Some(p) = self.get_max_height(node_data, node_id, node_state) {
            let _ = write!(s,"max-height: {};", p.get_css_value_fmt());
        }
        if let Some(p) = self.get_position(node_data, node_id, node_state) {
            let _ = write!(s,"position: {};", p.get_css_value_fmt());
        }
        if let Some(p) = self.get_top(node_data, node_id, node_state) {
            let _ = write!(s,"top: {};", p.get_css_value_fmt());
        }
        if let Some(p) = self.get_bottom(node_data, node_id, node_state) {
            let _ = write!(s,"bottom: {};", p.get_css_value_fmt());
        }
        if let Some(p) = self.get_right(node_data, node_id, node_state) {
            let _ = write!(s,"right: {};", p.get_css_value_fmt());
        }
        if let Some(p) = self.get_left(node_data, node_id, node_state) {
            let _ = write!(s,"left: {};", p.get_css_value_fmt());
        }
        if let Some(p) = self.get_padding_top(node_data, node_id, node_state) {
            let _ = write!(s,"padding-top: {};", p.get_css_value_fmt());
        }
        if let Some(p) = self.get_padding_bottom(node_data, node_id, node_state) {
            let _ = write!(s,"padding-bottom: {};", p.get_css_value_fmt());
        }
        if let Some(p) = self.get_padding_left(node_data, node_id, node_state) {
            let _ = write!(s,"padding-left: {};", p.get_css_value_fmt());
        }
        if let Some(p) = self.get_padding_right(node_data, node_id, node_state) {
            let _ = write!(s,"padding-right: {};", p.get_css_value_fmt());
        }
        if let Some(p) = self.get_margin_top(node_data, node_id, node_state) {
            let _ = write!(s,"margin-top: {};", p.get_css_value_fmt());
        }
        if let Some(p) = self.get_margin_bottom(node_data, node_id, node_state) {
            let _ = write!(s,"margin-bottom: {};", p.get_css_value_fmt());
        }
        if let Some(p) = self.get_margin_left(node_data, node_id, node_state) {
            let _ = write!(s,"margin-left: {};", p.get_css_value_fmt());
        }
        if let Some(p) = self.get_margin_right(node_data, node_id, node_state) {
            let _ = write!(s,"margin-right: {};", p.get_css_value_fmt());
        }
        if let Some(p) = self.get_border_top_width(node_data, node_id, node_state) {
            let _ = write!(s,"border-top-width: {};", p.get_css_value_fmt());
        }
        if let Some(p) = self.get_border_left_width(node_data, node_id, node_state) {
            let _ = write!(s,"border-left-width: {};", p.get_css_value_fmt());
        }
        if let Some(p) = self.get_border_right_width(node_data, node_id, node_state) {
            let _ = write!(s,"border-right-width: {};", p.get_css_value_fmt());
        }
        if let Some(p) = self.get_border_bottom_width(node_data, node_id, node_state) {
            let _ = write!(s,"border-bottom-width: {};", p.get_css_value_fmt());
        }
        if let Some(p) = self.get_overflow_x(node_data, node_id, node_state) {
            let _ = write!(s,"overflow-x: {};", p.get_css_value_fmt());
        }
        if let Some(p) = self.get_overflow_y(node_data, node_id, node_state) {
            let _ = write!(s,"overflow-y: {};", p.get_css_value_fmt());
        }
        if let Some(p) = self.get_flex_direction(node_data, node_id, node_state) {
            let _ = write!(s,"flex-direction: {};", p.get_css_value_fmt());
        }
        if let Some(p) = self.get_flex_wrap(node_data, node_id, node_state) {
            let _ = write!(s,"flex-wrap: {};", p.get_css_value_fmt());
        }
        if let Some(p) = self.get_flex_grow(node_data, node_id, node_state) {
            let _ = write!(s,"flex-grow: {};", p.get_css_value_fmt());
        }
        if let Some(p) = self.get_flex_shrink(node_data, node_id, node_state) {
            let _ = write!(s,"flex-shrink: {};", p.get_css_value_fmt());
        }
        if let Some(p) = self.get_justify_content(node_data, node_id, node_state) {
            let _ = write!(s,"justify-content: {};", p.get_css_value_fmt());
        }
        if let Some(p) = self.get_align_items(node_data, node_id, node_state) {
            let _ = write!(s,"align-items: {};", p.get_css_value_fmt());
        }
        if let Some(p) = self.get_align_content(node_data, node_id, node_state) {
            let _ = write!(s,"align-content: {};", p.get_css_value_fmt());
        }
        s
    }
}

#[repr(C)]
#[derive(Debug, PartialEq, Clone)]
pub struct CssPropertyCachePtr {
    // `ManuallyDrop` so the owned `Box` is freed ONLY by our `Drop` (gated on
    // `run_destructor`), never by drop-glue. The codegen Az wrapper (AzStyledDom)
    // nests an AzCssPropertyCachePtr field whose own `Drop` re-runs
    // `_delete` -> `drop_in_place::<CssPropertyCachePtr>` on the SAME bytes; with a
    // bare `Box` the glue freed it a second time -> double free. Layout is
    // unchanged (one pointer), so the AzCssPropertyCachePtr<->CssPropertyCachePtr
    // FFI transmute stays valid. Matches the GlContextPtr / InstantPtr convention.
    pub ptr: ManuallyDrop<Box<CssPropertyCache>>,
    pub run_destructor: bool,
}

impl CssPropertyCachePtr {
    pub fn new(cache: CssPropertyCache) -> Self {
        Self {
            ptr: ManuallyDrop::new(Box::new(cache)),
            run_destructor: true,
        }
    }
    pub fn downcast_mut(&mut self) -> &mut CssPropertyCache {
        &mut self.ptr
    }
}

impl Drop for CssPropertyCachePtr {
    fn drop(&mut self) {
        // First drop (run_destructor still true) frees the Box and clears the flag in
        // the shared bytes; the codegen's redundant second drop sees false -> no-op.
        if self.run_destructor {
            self.run_destructor = false;
            unsafe {
                ManuallyDrop::drop(&mut self.ptr);
            }
        }
    }
}

/// Generates a mechanical `get_<name>` CSS-property accessor: resolve the property
/// for `(node_data, node_id, node_state)` via `get_property`, then downcast it with
/// the given `as_*` method. Covers the long run of one-line accessors below.
macro_rules! impl_get_prop {
    ($name:ident, $value_ty:ty, $variant:ident, $as_method:ident) => {
        pub fn $name<'a>(
            &'a self,
            node_data: &'a NodeData,
            node_id: &NodeId,
            node_state: &StyledNodeState,
        ) -> Option<&'a $value_ty> {
            self.get_property(node_data, node_id, node_state, &CssPropertyType::$variant)
                .and_then(|p| p.$as_method())
        }
    };
}

impl CssPropertyCache {
    #[must_use] pub fn empty(node_count: usize) -> Self {
        Self {
            node_count,
            retained_author_css: Css::default(),
            user_overridden_properties: Vec::new(),

            cascaded_props: FlatVecVec::new(node_count),
            css_props: FlatVecVec::new(node_count),

            computed_values: Vec::new(),
            compact_cache: None,
            global_css_props: Vec::new(),
            resolved_font_sizes_px: crate::sync::OnceLock::new(),
        }
    }

    /// Clear the lazily-populated font-size cache. Call after any
    /// mutation that could change resolved font-sizes (restyle,
    /// DOM mutation, `append`, etc.). The next
    /// [`crate::styled_dom::StyledDom::resolved_font_size_px`] call
    /// repopulates via a single bottom-up tree walk.
    pub fn invalidate_resolved_font_sizes(&mut self) {
        self.resolved_font_sizes_px = crate::sync::OnceLock::new();
    }

    pub fn append(&mut self, other: &mut Self) {
        self.user_overridden_properties.append(&mut other.user_overridden_properties);
        self.cascaded_props.extend_from(&mut other.cascaded_props);
        self.css_props.extend_from(&mut other.css_props);
        self.computed_values.append(&mut other.computed_values);

        self.node_count += other.node_count;
        // Indices shifted — invalidate the font-size cache too.
        self.resolved_font_sizes_px = crate::sync::OnceLock::new();

        // Invalidate compact cache since node IDs shifted
        self.compact_cache = None;
    }

    pub fn is_horizontal_overflow_visible(
        &self,
        node_data: &NodeData,
        node_id: &NodeId,
        node_state: &StyledNodeState,
    ) -> bool {
        self.get_overflow_x(node_data, node_id, node_state)
            .and_then(|p| p.get_property_or_default())
            .unwrap_or_default()
            .is_overflow_visible()
    }

    pub fn is_vertical_overflow_visible(
        &self,
        node_data: &NodeData,
        node_id: &NodeId,
        node_state: &StyledNodeState,
    ) -> bool {
        self.get_overflow_y(node_data, node_id, node_state)
            .and_then(|p| p.get_property_or_default())
            .unwrap_or_default()
            .is_overflow_visible()
    }

    pub fn is_horizontal_overflow_hidden(
        &self,
        node_data: &NodeData,
        node_id: &NodeId,
        node_state: &StyledNodeState,
    ) -> bool {
        self.get_overflow_x(node_data, node_id, node_state)
            .and_then(|p| p.get_property_or_default())
            .unwrap_or_default()
            .is_overflow_hidden()
    }

    pub fn is_vertical_overflow_hidden(
        &self,
        node_data: &NodeData,
        node_id: &NodeId,
        node_state: &StyledNodeState,
    ) -> bool {
        self.get_overflow_y(node_data, node_id, node_state)
            .and_then(|p| p.get_property_or_default())
            .unwrap_or_default()
            .is_overflow_hidden()
    }

    pub fn get_text_color_or_default(
        &self,
        node_data: &NodeData,
        node_id: &NodeId,
        node_state: &StyledNodeState,
    ) -> StyleTextColor {
        use azul_css::defaults::DEFAULT_TEXT_COLOR;
        self.get_text_color(node_data, node_id, node_state)
            .and_then(|fs| fs.get_property().copied())
            .unwrap_or(DEFAULT_TEXT_COLOR)
    }

    /// Returns the font family of the node, or the default font family if none is set.
    pub fn get_font_id_or_default(
        &self,
        node_data: &NodeData,
        node_id: &NodeId,
        node_state: &StyledNodeState,
    ) -> StyleFontFamilyVec {
        use azul_css::defaults::DEFAULT_FONT_ID;
        let default_font_id = vec![StyleFontFamily::System(AzString::from_const_str(
            DEFAULT_FONT_ID,
        ))]
        .into();
        let font_family_opt = self.get_font_family(node_data, node_id, node_state);

        font_family_opt
            .as_ref()
            .and_then(|family| Some(family.get_property()?.clone()))
            .unwrap_or(default_font_id)
    }

    pub fn get_font_size_or_default(
        &self,
        node_data: &NodeData,
        node_id: &NodeId,
        node_state: &StyledNodeState,
    ) -> StyleFontSize {
        use azul_css::defaults::DEFAULT_FONT_SIZE;
        self.get_font_size(node_data, node_id, node_state)
            .and_then(|fs| fs.get_property().copied())
            .unwrap_or(DEFAULT_FONT_SIZE)
    }

    pub fn has_border(
        &self,
        node_data: &NodeData,
        node_id: &NodeId,
        node_state: &StyledNodeState,
    ) -> bool {
        self.get_border_left_width(node_data, node_id, node_state)
            .is_some()
            || self
                .get_border_right_width(node_data, node_id, node_state)
                .is_some()
            || self
                .get_border_top_width(node_data, node_id, node_state)
                .is_some()
            || self
                .get_border_bottom_width(node_data, node_id, node_state)
                .is_some()
    }

    pub fn has_box_shadow(
        &self,
        node_data: &NodeData,
        node_id: &NodeId,
        node_state: &StyledNodeState,
    ) -> bool {
        self.get_box_shadow_left(node_data, node_id, node_state)
            .is_some()
            || self
                .get_box_shadow_right(node_data, node_id, node_state)
                .is_some()
            || self
                .get_box_shadow_top(node_data, node_id, node_state)
                .is_some()
            || self
                .get_box_shadow_bottom(node_data, node_id, node_state)
                .is_some()
    }

    pub fn get_property<'a>(
        &'a self,
        node_data: &'a NodeData,
        node_id: &NodeId,
        node_state: &StyledNodeState,
        css_property_type: &CssPropertyType,
    ) -> Option<&'a CssProperty> {
        // Thread-local counter of cascade walks, broken down by
        // property type. Drain with `drain_css_prop_counts` (free
        // fn below) when `AZ_PROP_COUNT=1` is set to see which
        // properties dominate the cold layout path.
        //
        // Env check is read ONCE at process start and cached in a
        // `OnceLock<bool>`. Before this, the env check ran per
        // `get_property` call — and the function fires 710k+ times
        // per cold layout on excel.html. `std::env::var_os` takes
        // ~100 ns per call on macOS (env lock + hashmap lookup), so
        // the naive check added ~70 ms of pure noise to every
        // single layout, regardless of whether the env var was set.
        // Using a one-time cached bool removes that overhead.
        //
        // `no_std` builds have no thread-locals / env, so the profiling
        // counter is compiled out entirely.
        #[cfg(feature = "std")]
        {
            static PROP_COUNT_ENABLED: std::sync::OnceLock<bool> = std::sync::OnceLock::new();
            let enabled = *PROP_COUNT_ENABLED.get_or_init(crate::profile::cascade_enabled);
            if enabled {
                // `try_with` (not `with`): the lifted-to-wasm web backend has no
                // real TLS, so `with` would hit `panic_access_error` (the layout
                // path reads CSS props via these getters → would trap). `try_with`
                // returns Err and we skip the profiling-only increment (and its
                // inner Mutex-guarded label table). Desktop behaviour unchanged —
                // when the env var is unset the whole block is gated off anyway.
                let _ = PROP_COUNTS.try_with(|c| {
                    *c.borrow_mut()
                        .entry(Self::css_prop_type_label(css_property_type))
                        .or_insert(0) += 1;
                });
            }
        }

        // Always use full cascade resolution.
        // Tier 1/2/2b handle layout-hot properties via direct typed getters.
        // This path is only used for paint-time reads (background, shadow, etc.)
        self.get_property_slow(node_data, node_id, node_state, css_property_type)
    }

    #[cfg(feature = "std")]
    #[allow(clippy::trivially_copy_pass_by_ref)] // uniform by-ref cascade-API convention (see find_in_stateful)
    fn css_prop_type_label(t: &CssPropertyType) -> &'static str {
        // Intern Debug-format labels under a mutex-guarded map so
        // we leak at most one `&'static str` per distinct
        // `CssPropertyType` variant (bounded at ≤ 178 total). Only
        // triggered when `AZ_PROP_COUNT=1`, so zero cost normally.
        use std::sync::{Mutex, OnceLock};
        static TABLE: OnceLock<Mutex<std::collections::HashMap<CssPropertyType, &'static str>>> =
            OnceLock::new();
        let m = TABLE.get_or_init(|| Mutex::new(std::collections::HashMap::new()));
        let mut g = m.lock().expect("AZ_PROP_COUNT label table poisoned");
        if let Some(s) = g.get(t) {
            return s;
        }
        let s: String = std::format!("{t:?}");
        let leaked: &'static str = std::boxed::Box::leak(s.into_boxed_str());
        g.insert(*t, leaked);
        leaked
    }

    /// Full cascade resolution for any CSS property type.
    /// Walks all cascade layers: user overrides → inline → stylesheet → cascaded → computed → UA.
    /// Also used by restyle functions that need state-aware lookups.
    #[allow(clippy::trivially_copy_pass_by_ref)] // uniform by-ref cascade-API convention (see find_in_stateful)
    #[allow(clippy::too_many_lines)] // large but cohesive: single-purpose parser/builder/dispatch (one branch per input variant)
    pub(crate) fn get_property_slow<'a>(
        &'a self,
        node_data: &'a NodeData,
        node_id: &NodeId,
        node_state: &StyledNodeState,
        css_property_type: &CssPropertyType,
    ) -> Option<&'a CssProperty> {

        use azul_css::dynamic_selector::{DynamicSelector, PseudoStateType};

        // Helper: do these conditions identify a rule that applies in `state`?
        // Empty conditions = Normal-only. Otherwise all conditions must be
        // PseudoState(state).
        fn matches_pseudo_state(
            conds: &azul_css::dynamic_selector::DynamicSelectorVec,
            state: PseudoStateType,
        ) -> bool {
            let conditions = conds.as_slice();
            if conditions.is_empty() {
                state == PseudoStateType::Normal
            } else {
                conditions
                    .iter()
                    .all(|c| matches!(c, DynamicSelector::PseudoState(s) if *s == state))
            }
        }

        // First test if there is some user-defined override for the property
        if let Some(v) = self.user_overridden_properties.get(node_id.index()) {
            if let Ok(idx) = v.binary_search_by_key(css_property_type, |(k, _)| *k) {
                return Some(&v[idx].1);
            }
        }

        // If that fails, see if there is an inline CSS property that matches
        // :focus > :active > :hover > normal (fallback)
        if node_state.focused {
            // PRIORITY 1: Inline CSS properties (highest priority per CSS spec)
            if let Some(p) = node_data.style.iter_inline_properties().find_map(|(prop, conds)| {
                if matches_pseudo_state(conds,PseudoStateType::Focus)
                    && prop.get_type() == *css_property_type
                {
                    Some(prop)
                } else {
                    None
                }
            }) {
                return Some(p);
            }

            // PRIORITY 2: CSS stylesheet properties
            if let Some(p) = Self::find_in_stateful(
                self.css_props.get_slice(node_id.index()),
                PseudoStateType::Focus,
                css_property_type,
            ) {
                return Some(p);
            }

            // PRIORITY 3: Cascaded/inherited properties
            if let Some(p) = Self::find_in_stateful(
                self.cascaded_props.get_slice(node_id.index()),
                PseudoStateType::Focus,
                css_property_type,
            ) {
                return Some(p);
            }
        }

        if node_state.active {
            // PRIORITY 1: Inline CSS properties (highest priority per CSS spec)
            if let Some(p) = node_data.style.iter_inline_properties().find_map(|(prop, conds)| {
                if matches_pseudo_state(conds,PseudoStateType::Active)
                    && prop.get_type() == *css_property_type
                {
                    Some(prop)
                } else {
                    None
                }
            }) {
                return Some(p);
            }

            // PRIORITY 2: CSS stylesheet properties
            if let Some(p) = Self::find_in_stateful(
                self.css_props.get_slice(node_id.index()),
                PseudoStateType::Active,
                css_property_type,
            ) {
                return Some(p);
            }

            // PRIORITY 3: Cascaded/inherited properties
            if let Some(p) = Self::find_in_stateful(
                self.cascaded_props.get_slice(node_id.index()),
                PseudoStateType::Active,
                css_property_type,
            ) {
                return Some(p);
            }
        }

        // :dragging pseudo-state (higher priority than :hover)
        if node_state.dragging {
            if let Some(p) = node_data.style.iter_inline_properties().find_map(|(prop, conds)| {
                if matches_pseudo_state(conds,PseudoStateType::Dragging)
                    && prop.get_type() == *css_property_type
                {
                    Some(prop)
                } else {
                    None
                }
            }) {
                return Some(p);
            }

            if let Some(p) = Self::find_in_stateful(
                self.css_props.get_slice(node_id.index()),
                PseudoStateType::Dragging,
                css_property_type,
            ) {
                return Some(p);
            }

            if let Some(p) = Self::find_in_stateful(
                self.cascaded_props.get_slice(node_id.index()),
                PseudoStateType::Dragging,
                css_property_type,
            ) {
                return Some(p);
            }
        }

        // :drag-over pseudo-state (higher priority than :hover)
        if node_state.drag_over {
            if let Some(p) = node_data.style.iter_inline_properties().find_map(|(prop, conds)| {
                if matches_pseudo_state(conds,PseudoStateType::DragOver)
                    && prop.get_type() == *css_property_type
                {
                    Some(prop)
                } else {
                    None
                }
            }) {
                return Some(p);
            }

            if let Some(p) = Self::find_in_stateful(
                self.css_props.get_slice(node_id.index()),
                PseudoStateType::DragOver,
                css_property_type,
            ) {
                return Some(p);
            }

            if let Some(p) = Self::find_in_stateful(
                self.cascaded_props.get_slice(node_id.index()),
                PseudoStateType::DragOver,
                css_property_type,
            ) {
                return Some(p);
            }
        }

        if node_state.hover {
            // PRIORITY 1: Inline CSS properties (highest priority per CSS spec)
            if let Some(p) = node_data.style.iter_inline_properties().find_map(|(prop, conds)| {
                if matches_pseudo_state(conds,PseudoStateType::Hover)
                    && prop.get_type() == *css_property_type
                {
                    Some(prop)
                } else {
                    None
                }
            }) {
                return Some(p);
            }

            // PRIORITY 2: CSS stylesheet properties
            if let Some(p) = Self::find_in_stateful(
                self.css_props.get_slice(node_id.index()),
                PseudoStateType::Hover,
                css_property_type,
            ) {
                return Some(p);
            }

            // PRIORITY 3: Cascaded/inherited properties
            if let Some(p) = Self::find_in_stateful(
                self.cascaded_props.get_slice(node_id.index()),
                PseudoStateType::Hover,
                css_property_type,
            ) {
                return Some(p);
            }
        }

        // Normal/fallback properties - always apply as base layer
        // PRIORITY 1: Inline CSS properties (highest priority per CSS spec)
        if let Some(p) = node_data.style.iter_inline_properties().find_map(|(prop, conds)| {
            if matches_pseudo_state(conds, PseudoStateType::Normal)
                && prop.get_type() == *css_property_type
            {
                Some(prop)
            } else {
                None
            }
        }) {
            return Some(p);
        }

        // PRIORITY 2: CSS stylesheet properties
        if let Some(p) = Self::find_in_stateful(
            self.css_props.get_slice(node_id.index()),
            PseudoStateType::Normal,
            css_property_type,
        ) {
            return Some(p);
        }

        // PRIORITY 2b: Global `*` selector properties (specificity 0,0,0)
        // These are collected once during restyle and apply to all nodes.
        // Lower priority than per-node rules but higher than inheritance/UA.
        if let Some(p) = self.global_css_props.iter().find(|p| p.get_type() == *css_property_type) {
            return Some(p);
        }

        // PRIORITY 3: Cascaded/inherited properties
        if let Some(p) = Self::find_in_stateful(
            self.cascaded_props.get_slice(node_id.index()),
            PseudoStateType::Normal,
            css_property_type,
        ) {
            return Some(p);
        }

        // Check computed values cache for inherited properties
        // Sorted Vec with binary search
        if css_property_type.is_inheritable() {
            if let Some(vec) = self.computed_values.get(node_id.index()) {
                if let Ok(idx) = vec.binary_search_by_key(css_property_type, |(k, _)| *k) {
                    return Some(&vec[idx].1.property);
                }
            }
        }

        // User-agent stylesheet fallback (lowest precedence)
        // Check if the node type has a default value for this property
        crate::ua_css::get_ua_property(&node_data.node_type, *css_property_type)
    }

    /// Get a CSS property using `DynamicSelectorContext` for evaluation.
    ///
    /// This is the new API that supports @media queries, @container queries,
    /// OS-specific styles, and all pseudo-states via `CssPropertyWithConditions`.
    ///
    /// The evaluation follows "last wins" semantics - properties are evaluated
    /// in reverse order and the first matching property wins.
    #[allow(clippy::trivially_copy_pass_by_ref)] // uniform by-ref cascade-API convention (see find_in_stateful)
    pub(crate) fn get_property_with_context<'a>(
        &'a self,
        node_data: &'a NodeData,
        node_id: &NodeId,
        context: &DynamicSelectorContext,
        css_property_type: &CssPropertyType,
    ) -> Option<&'a CssProperty> {
        // First test if there is some user-defined override for the property
        if let Some(v) = self.user_overridden_properties.get(node_id.index()) {
            if let Ok(idx) = v.binary_search_by_key(css_property_type, |(k, _)| *k) {
                return Some(&v[idx].1);
            }
        }

        // Check inline CSS properties with DynamicSelectorContext evaluation.
        // Iterate in REVERSE order across the flat (prop, conds) view —
        // "last found wins" semantics, replacing the old Focus > Active >
        // Hover > Normal priority chain.
        // "last found wins": scan the flat (prop, conds) view forward and keep the
        // last match (iter_inline_properties is not DoubleEndedIterator, so this
        // replaces an earlier collect-then-rev-find_map).
        let mut last_inline = None;
        for (prop, conds) in node_data.style.iter_inline_properties() {
            let conditions_match = conds.as_slice().iter().all(|c| c.matches(context));
            if prop.get_type() == *css_property_type && conditions_match {
                last_inline = Some(prop);
            }
        }
        if let Some(prop) = last_inline {
            return Some(prop);
        }

        // Fall back to CSS file and cascaded properties
        let legacy_state = StyledNodeState::from_pseudo_state_flags(&context.pseudo_state);
        if let Some(p) = self.get_property(node_data, node_id, &legacy_state, css_property_type) {
            return Some(p);
        }

        None
    }

    /// Check if any properties with conditions would change between two contexts.
    /// This is used for re-layout detection on viewport/container resize.
    pub(crate) fn check_properties_changed(
        node_data: &NodeData,
        old_context: &DynamicSelectorContext,
        new_context: &DynamicSelectorContext,
    ) -> bool {
        for (_prop, conds) in node_data.style.iter_inline_properties() {
            let was_active = conds.as_slice().iter().all(|c| c.matches(old_context));
            let is_active = conds.as_slice().iter().all(|c| c.matches(new_context));
            if was_active != is_active {
                return true;
            }
        }
        false
    }

    /// Check if any layout-affecting properties would change between two contexts.
    /// This is a more targeted check for re-layout detection.
    pub(crate) fn check_layout_properties_changed(
        node_data: &NodeData,
        old_context: &DynamicSelectorContext,
        new_context: &DynamicSelectorContext,
    ) -> bool {
        for (prop, conds) in node_data.style.iter_inline_properties() {
            // Skip non-layout-affecting properties
            if !prop.get_type().can_trigger_relayout() {
                continue;
            }

            let was_active = conds.as_slice().iter().all(|c| c.matches(old_context));
            let is_active = conds.as_slice().iter().all(|c| c.matches(new_context));
            if was_active != is_active {
                return true;
            }
        }
        false
    }

    impl_get_prop!(get_background_content, StyleBackgroundContentVecValue, BackgroundContent, as_background_content);

    impl_get_prop!(get_hyphens, StyleHyphensValue, Hyphens, as_hyphens);

    impl_get_prop!(get_word_break, StyleWordBreakValue, WordBreak, as_word_break);

    impl_get_prop!(get_overflow_wrap, StyleOverflowWrapValue, OverflowWrap, as_overflow_wrap);

    impl_get_prop!(get_line_break, StyleLineBreakValue, LineBreak, as_line_break);

    impl_get_prop!(get_text_align_last, StyleTextAlignLastValue, TextAlignLast, as_text_align_last);

    impl_get_prop!(get_text_transform, StyleTextTransformValue, TextTransform, as_text_transform);

    impl_get_prop!(get_object_fit, StyleObjectFitValue, ObjectFit, as_object_fit);

    impl_get_prop!(get_text_overflow, StyleTextOverflowValue, TextOverflow, as_text_overflow);

    impl_get_prop!(get_text_orientation, StyleTextOrientationValue, TextOrientation, as_text_orientation);

    impl_get_prop!(get_object_position, StyleObjectPositionValue, ObjectPosition, as_object_position);

    impl_get_prop!(get_aspect_ratio, StyleAspectRatioValue, AspectRatio, as_aspect_ratio);

    impl_get_prop!(get_direction, StyleDirectionValue, Direction, as_direction);

    impl_get_prop!(get_unicode_bidi, StyleUnicodeBidiValue, UnicodeBidi, as_unicode_bidi);

    impl_get_prop!(get_text_box_trim, StyleTextBoxTrimValue, TextBoxTrim, as_text_box_trim);

    impl_get_prop!(get_text_box_edge, StyleTextBoxEdgeValue, TextBoxEdge, as_text_box_edge);

    impl_get_prop!(get_dominant_baseline, StyleDominantBaselineValue, DominantBaseline, as_dominant_baseline);

    impl_get_prop!(get_alignment_baseline, StyleAlignmentBaselineValue, AlignmentBaseline, as_alignment_baseline);

    impl_get_prop!(get_baseline_source, StyleBaselineSourceValue, BaselineSource, as_baseline_source);

    impl_get_prop!(get_line_fit_edge, StyleLineFitEdgeValue, LineFitEdge, as_line_fit_edge);

    impl_get_prop!(get_initial_letter_align, StyleInitialLetterAlignValue, InitialLetterAlign, as_initial_letter_align);

    impl_get_prop!(get_initial_letter_wrap, StyleInitialLetterWrapValue, InitialLetterWrap, as_initial_letter_wrap);

    impl_get_prop!(get_scrollbar_gutter, StyleScrollbarGutterValue, ScrollbarGutter, as_scrollbar_gutter);

    impl_get_prop!(get_overflow_clip_margin, StyleOverflowClipMarginValue, OverflowClipMargin, as_overflow_clip_margin);

    impl_get_prop!(get_clip, StyleClipRectValue, Clip, as_clip);

    impl_get_prop!(get_white_space, StyleWhiteSpaceValue, WhiteSpace, as_white_space);
    impl_get_prop!(get_background_position, StyleBackgroundPositionVecValue, BackgroundPosition, as_background_position);
    impl_get_prop!(get_background_size, StyleBackgroundSizeVecValue, BackgroundSize, as_background_size);
    impl_get_prop!(get_background_repeat, StyleBackgroundRepeatVecValue, BackgroundRepeat, as_background_repeat);
    impl_get_prop!(get_font_size, StyleFontSizeValue, FontSize, as_font_size);
    impl_get_prop!(get_font_family, StyleFontFamilyVecValue, FontFamily, as_font_family);
    impl_get_prop!(get_font_weight, StyleFontWeightValue, FontWeight, as_font_weight);
    impl_get_prop!(get_font_style, StyleFontStyleValue, FontStyle, as_font_style);
    impl_get_prop!(get_text_color, StyleTextColorValue, TextColor, as_text_color);
    impl_get_prop!(get_text_indent, StyleTextIndentValue, TextIndent, as_text_indent);
    impl_get_prop!(get_initial_letter, StyleInitialLetterValue, InitialLetter, as_initial_letter);
    impl_get_prop!(get_line_clamp, StyleLineClampValue, LineClamp, as_line_clamp);
    impl_get_prop!(get_hanging_punctuation, StyleHangingPunctuationValue, HangingPunctuation, as_hanging_punctuation);
    impl_get_prop!(get_text_combine_upright, StyleTextCombineUprightValue, TextCombineUpright, as_text_combine_upright);
    impl_get_prop!(get_exclusion_margin, StyleExclusionMarginValue, ExclusionMargin, as_exclusion_margin);
    impl_get_prop!(get_hyphenation_language, StyleHyphenationLanguageValue, HyphenationLanguage, as_hyphenation_language);
    impl_get_prop!(get_caret_color, CaretColorValue, CaretColor, as_caret_color);

    impl_get_prop!(get_caret_width, CaretWidthValue, CaretWidth, as_caret_width);

    impl_get_prop!(get_caret_animation_duration, CaretAnimationDurationValue, CaretAnimationDuration, as_caret_animation_duration);

    impl_get_prop!(get_selection_background_color, SelectionBackgroundColorValue, SelectionBackgroundColor, as_selection_background_color);

    impl_get_prop!(get_selection_color, SelectionColorValue, SelectionColor, as_selection_color);

    impl_get_prop!(get_selection_radius, SelectionRadiusValue, SelectionRadius, as_selection_radius);

    impl_get_prop!(get_text_justify, LayoutTextJustifyValue, TextJustify, as_text_justify);

    impl_get_prop!(get_z_index, LayoutZIndexValue, ZIndex, as_z_index);

    impl_get_prop!(get_flex_basis, LayoutFlexBasisValue, FlexBasis, as_flex_basis);

    impl_get_prop!(get_column_gap, LayoutColumnGapValue, ColumnGap, as_column_gap);

    impl_get_prop!(get_row_gap, LayoutRowGapValue, RowGap, as_row_gap);

    impl_get_prop!(get_grid_template_columns, LayoutGridTemplateColumnsValue, GridTemplateColumns, as_grid_template_columns);

    impl_get_prop!(get_grid_template_rows, LayoutGridTemplateRowsValue, GridTemplateRows, as_grid_template_rows);

    impl_get_prop!(get_grid_auto_columns, LayoutGridAutoColumnsValue, GridAutoColumns, as_grid_auto_columns);

    impl_get_prop!(get_grid_auto_rows, LayoutGridAutoRowsValue, GridAutoRows, as_grid_auto_rows);

    impl_get_prop!(get_grid_column, LayoutGridColumnValue, GridColumn, as_grid_column);

    impl_get_prop!(get_grid_row, LayoutGridRowValue, GridRow, as_grid_row);

    impl_get_prop!(get_grid_auto_flow, LayoutGridAutoFlowValue, GridAutoFlow, as_grid_auto_flow);

    impl_get_prop!(get_justify_self, LayoutJustifySelfValue, JustifySelf, as_justify_self);

    impl_get_prop!(get_justify_items, LayoutJustifyItemsValue, JustifyItems, as_justify_items);

    impl_get_prop!(get_gap, LayoutGapValue, Gap, as_gap);

    /// Method for getting grid-gap property
    #[allow(clippy::trivially_copy_pass_by_ref)] // uniform by-ref cascade-API convention (see find_in_stateful)
    pub(crate) fn get_grid_gap<'a>(
        &'a self,
        node_data: &'a NodeData,
        node_id: &NodeId,
        node_state: &StyledNodeState,
    ) -> Option<&'a LayoutGapValue> {
        self.get_property(node_data, node_id, node_state, &CssPropertyType::GridGap)
            .and_then(|p| p.as_grid_gap())
    }

    impl_get_prop!(get_align_self, LayoutAlignSelfValue, AlignSelf, as_align_self);

    impl_get_prop!(get_font, StyleFontValue, Font, as_font);

    impl_get_prop!(get_writing_mode, LayoutWritingModeValue, WritingMode, as_writing_mode);

    impl_get_prop!(get_clear, LayoutClearValue, Clear, as_clear);

    impl_get_prop!(get_shape_outside, ShapeOutsideValue, ShapeOutside, as_shape_outside);

    impl_get_prop!(get_shape_inside, ShapeInsideValue, ShapeInside, as_shape_inside);

    impl_get_prop!(get_clip_path, ClipPathValue, ClipPath, as_clip_path);

    /// Method for getting scrollbar track background
    pub fn get_scrollbar_track<'a>(
        &'a self,
        node_data: &'a NodeData,
        node_id: &NodeId,
        node_state: &StyledNodeState,
    ) -> Option<&'a StyleBackgroundContentValue> {
        self.get_property(node_data, node_id, node_state, &CssPropertyType::ScrollbarTrack)
            .and_then(|p| p.as_scrollbar_track())
    }

    /// Method for getting scrollbar thumb background
    pub fn get_scrollbar_thumb<'a>(
        &'a self,
        node_data: &'a NodeData,
        node_id: &NodeId,
        node_state: &StyledNodeState,
    ) -> Option<&'a StyleBackgroundContentValue> {
        self.get_property(node_data, node_id, node_state, &CssPropertyType::ScrollbarThumb)
            .and_then(|p| p.as_scrollbar_thumb())
    }

    /// Method for getting scrollbar button background
    pub fn get_scrollbar_button<'a>(
        &'a self,
        node_data: &'a NodeData,
        node_id: &NodeId,
        node_state: &StyledNodeState,
    ) -> Option<&'a StyleBackgroundContentValue> {
        self.get_property(node_data, node_id, node_state, &CssPropertyType::ScrollbarButton)
            .and_then(|p| p.as_scrollbar_button())
    }

    /// Method for getting scrollbar corner background
    pub fn get_scrollbar_corner<'a>(
        &'a self,
        node_data: &'a NodeData,
        node_id: &NodeId,
        node_state: &StyledNodeState,
    ) -> Option<&'a StyleBackgroundContentValue> {
        self.get_property(node_data, node_id, node_state, &CssPropertyType::ScrollbarCorner)
            .and_then(|p| p.as_scrollbar_corner())
    }

    /// Method for getting scrollbar resizer background
    pub fn get_scrollbar_resizer<'a>(
        &'a self,
        node_data: &'a NodeData,
        node_id: &NodeId,
        node_state: &StyledNodeState,
    ) -> Option<&'a StyleBackgroundContentValue> {
        self.get_property(node_data, node_id, node_state, &CssPropertyType::ScrollbarResizer)
            .and_then(|p| p.as_scrollbar_resizer())
    }

    impl_get_prop!(get_scrollbar_width, LayoutScrollbarWidthValue, ScrollbarWidth, as_scrollbar_width);

    impl_get_prop!(get_scrollbar_color, StyleScrollbarColorValue, ScrollbarColor, as_scrollbar_color);

    impl_get_prop!(get_scrollbar_visibility, ScrollbarVisibilityModeValue, ScrollbarVisibility, as_scrollbar_visibility);

    impl_get_prop!(get_scrollbar_fade_delay, ScrollbarFadeDelayValue, ScrollbarFadeDelay, as_scrollbar_fade_delay);

    impl_get_prop!(get_scrollbar_fade_duration, ScrollbarFadeDurationValue, ScrollbarFadeDuration, as_scrollbar_fade_duration);

    impl_get_prop!(get_visibility, StyleVisibilityValue, Visibility, as_visibility);

    impl_get_prop!(get_break_before, PageBreakValue, BreakBefore, as_break_before);

    impl_get_prop!(get_break_after, PageBreakValue, BreakAfter, as_break_after);

    impl_get_prop!(get_break_inside, BreakInsideValue, BreakInside, as_break_inside);

    impl_get_prop!(get_orphans, OrphansValue, Orphans, as_orphans);

    impl_get_prop!(get_widows, WidowsValue, Widows, as_widows);

    impl_get_prop!(get_box_decoration_break, BoxDecorationBreakValue, BoxDecorationBreak, as_box_decoration_break);

    impl_get_prop!(get_column_count, ColumnCountValue, ColumnCount, as_column_count);

    impl_get_prop!(get_column_width, ColumnWidthValue, ColumnWidth, as_column_width);

    impl_get_prop!(get_column_span, ColumnSpanValue, ColumnSpan, as_column_span);

    impl_get_prop!(get_column_fill, ColumnFillValue, ColumnFill, as_column_fill);

    impl_get_prop!(get_column_rule_width, ColumnRuleWidthValue, ColumnRuleWidth, as_column_rule_width);

    impl_get_prop!(get_column_rule_style, ColumnRuleStyleValue, ColumnRuleStyle, as_column_rule_style);

    impl_get_prop!(get_column_rule_color, ColumnRuleColorValue, ColumnRuleColor, as_column_rule_color);

    impl_get_prop!(get_flow_into, FlowIntoValue, FlowInto, as_flow_into);

    impl_get_prop!(get_flow_from, FlowFromValue, FlowFrom, as_flow_from);

    impl_get_prop!(get_shape_margin, ShapeMarginValue, ShapeMargin, as_shape_margin);

    impl_get_prop!(get_shape_image_threshold, ShapeImageThresholdValue, ShapeImageThreshold, as_shape_image_threshold);

    impl_get_prop!(get_content, ContentValue, Content, as_content);

    impl_get_prop!(get_counter_reset, CounterResetValue, CounterReset, as_counter_reset);

    impl_get_prop!(get_counter_increment, CounterIncrementValue, CounterIncrement, as_counter_increment);

    impl_get_prop!(get_string_set, StringSetValue, StringSet, as_string_set);
    impl_get_prop!(get_text_align, StyleTextAlignValue, TextAlign, as_text_align);
    impl_get_prop!(get_user_select, StyleUserSelectValue, UserSelect, as_user_select);
    impl_get_prop!(get_text_decoration, StyleTextDecorationValue, TextDecoration, as_text_decoration);
    impl_get_prop!(get_vertical_align, StyleVerticalAlignValue, VerticalAlign, as_vertical_align);
    impl_get_prop!(get_line_height, StyleLineHeightValue, LineHeight, as_line_height);
    impl_get_prop!(get_letter_spacing, StyleLetterSpacingValue, LetterSpacing, as_letter_spacing);
    impl_get_prop!(get_word_spacing, StyleWordSpacingValue, WordSpacing, as_word_spacing);
    impl_get_prop!(get_tab_size, StyleTabSizeValue, TabSize, as_tab_size);
    impl_get_prop!(get_cursor, StyleCursorValue, Cursor, as_cursor);
    impl_get_prop!(get_box_shadow_left, StyleBoxShadowValue, BoxShadowLeft, as_box_shadow_left);
    impl_get_prop!(get_box_shadow_right, StyleBoxShadowValue, BoxShadowRight, as_box_shadow_right);
    impl_get_prop!(get_box_shadow_top, StyleBoxShadowValue, BoxShadowTop, as_box_shadow_top);
    impl_get_prop!(get_box_shadow_bottom, StyleBoxShadowValue, BoxShadowBottom, as_box_shadow_bottom);
    impl_get_prop!(get_border_top_color, StyleBorderTopColorValue, BorderTopColor, as_border_top_color);
    impl_get_prop!(get_border_left_color, StyleBorderLeftColorValue, BorderLeftColor, as_border_left_color);
    impl_get_prop!(get_border_right_color, StyleBorderRightColorValue, BorderRightColor, as_border_right_color);
    impl_get_prop!(get_border_bottom_color, StyleBorderBottomColorValue, BorderBottomColor, as_border_bottom_color);
    impl_get_prop!(get_border_top_style, StyleBorderTopStyleValue, BorderTopStyle, as_border_top_style);
    impl_get_prop!(get_border_left_style, StyleBorderLeftStyleValue, BorderLeftStyle, as_border_left_style);
    impl_get_prop!(get_border_right_style, StyleBorderRightStyleValue, BorderRightStyle, as_border_right_style);
    impl_get_prop!(get_border_bottom_style, StyleBorderBottomStyleValue, BorderBottomStyle, as_border_bottom_style);
    impl_get_prop!(get_border_top_left_radius, StyleBorderTopLeftRadiusValue, BorderTopLeftRadius, as_border_top_left_radius);
    impl_get_prop!(get_border_top_right_radius, StyleBorderTopRightRadiusValue, BorderTopRightRadius, as_border_top_right_radius);
    impl_get_prop!(get_border_bottom_left_radius, StyleBorderBottomLeftRadiusValue, BorderBottomLeftRadius, as_border_bottom_left_radius);
    impl_get_prop!(get_border_bottom_right_radius, StyleBorderBottomRightRadiusValue, BorderBottomRightRadius, as_border_bottom_right_radius);
    impl_get_prop!(get_opacity, StyleOpacityValue, Opacity, as_opacity);
    impl_get_prop!(get_transform, StyleTransformVecValue, Transform, as_transform);
    impl_get_prop!(get_transform_origin, StyleTransformOriginValue, TransformOrigin, as_transform_origin);
    impl_get_prop!(get_perspective_origin, StylePerspectiveOriginValue, PerspectiveOrigin, as_perspective_origin);
    impl_get_prop!(get_backface_visibility, StyleBackfaceVisibilityValue, BackfaceVisibility, as_backface_visibility);
    impl_get_prop!(get_display, LayoutDisplayValue, Display, as_display);
    impl_get_prop!(get_float, LayoutFloatValue, Float, as_float);
    impl_get_prop!(get_box_sizing, LayoutBoxSizingValue, BoxSizing, as_box_sizing);
    impl_get_prop!(get_width, LayoutWidthValue, Width, as_width);
    impl_get_prop!(get_height, LayoutHeightValue, Height, as_height);
    impl_get_prop!(get_min_width, LayoutMinWidthValue, MinWidth, as_min_width);
    impl_get_prop!(get_min_height, LayoutMinHeightValue, MinHeight, as_min_height);
    impl_get_prop!(get_max_width, LayoutMaxWidthValue, MaxWidth, as_max_width);
    impl_get_prop!(get_max_height, LayoutMaxHeightValue, MaxHeight, as_max_height);
    impl_get_prop!(get_position, LayoutPositionValue, Position, as_position);
    impl_get_prop!(get_top, LayoutTopValue, Top, as_top);
    impl_get_prop!(get_bottom, LayoutInsetBottomValue, Bottom, as_bottom);
    impl_get_prop!(get_right, LayoutRightValue, Right, as_right);
    impl_get_prop!(get_left, LayoutLeftValue, Left, as_left);
    impl_get_prop!(get_padding_top, LayoutPaddingTopValue, PaddingTop, as_padding_top);
    impl_get_prop!(get_padding_bottom, LayoutPaddingBottomValue, PaddingBottom, as_padding_bottom);
    impl_get_prop!(get_padding_left, LayoutPaddingLeftValue, PaddingLeft, as_padding_left);
    impl_get_prop!(get_padding_right, LayoutPaddingRightValue, PaddingRight, as_padding_right);
    impl_get_prop!(get_margin_top, LayoutMarginTopValue, MarginTop, as_margin_top);
    impl_get_prop!(get_margin_bottom, LayoutMarginBottomValue, MarginBottom, as_margin_bottom);
    impl_get_prop!(get_margin_left, LayoutMarginLeftValue, MarginLeft, as_margin_left);
    impl_get_prop!(get_margin_right, LayoutMarginRightValue, MarginRight, as_margin_right);
    impl_get_prop!(get_border_top_width, LayoutBorderTopWidthValue, BorderTopWidth, as_border_top_width);
    impl_get_prop!(get_border_left_width, LayoutBorderLeftWidthValue, BorderLeftWidth, as_border_left_width);
    impl_get_prop!(get_border_right_width, LayoutBorderRightWidthValue, BorderRightWidth, as_border_right_width);
    impl_get_prop!(get_border_bottom_width, LayoutBorderBottomWidthValue, BorderBottomWidth, as_border_bottom_width);
    impl_get_prop!(get_overflow_x, LayoutOverflowValue, OverflowX, as_overflow_x);
    impl_get_prop!(get_overflow_y, LayoutOverflowValue, OverflowY, as_overflow_y);
    impl_get_prop!(get_overflow_block, LayoutOverflowValue, OverflowBlock, as_overflow_block);
    impl_get_prop!(get_overflow_inline, LayoutOverflowValue, OverflowInline, as_overflow_inline);
    impl_get_prop!(get_flex_direction, LayoutFlexDirectionValue, FlexDirection, as_flex_direction);
    impl_get_prop!(get_flex_wrap, LayoutFlexWrapValue, FlexWrap, as_flex_wrap);
    impl_get_prop!(get_flex_grow, LayoutFlexGrowValue, FlexGrow, as_flex_grow);
    impl_get_prop!(get_flex_shrink, LayoutFlexShrinkValue, FlexShrink, as_flex_shrink);
    impl_get_prop!(get_justify_content, LayoutJustifyContentValue, JustifyContent, as_justify_content);
    impl_get_prop!(get_align_items, LayoutAlignItemsValue, AlignItems, as_align_items);
    impl_get_prop!(get_align_content, LayoutAlignContentValue, AlignContent, as_align_content);
    impl_get_prop!(get_mix_blend_mode, StyleMixBlendModeValue, MixBlendMode, as_mix_blend_mode);
    impl_get_prop!(get_filter, StyleFilterVecValue, Filter, as_filter);
    impl_get_prop!(get_backdrop_filter, StyleFilterVecValue, BackdropFilter, as_backdrop_filter);
    impl_get_prop!(get_text_shadow, StyleBoxShadowValue, TextShadow, as_text_shadow);
    impl_get_prop!(get_list_style_type, StyleListStyleTypeValue, ListStyleType, as_list_style_type);
    impl_get_prop!(get_list_style_position, StyleListStylePositionValue, ListStylePosition, as_list_style_position);
    impl_get_prop!(get_table_layout, LayoutTableLayoutValue, TableLayout, as_table_layout);
    impl_get_prop!(get_border_collapse, StyleBorderCollapseValue, BorderCollapse, as_border_collapse);
    impl_get_prop!(get_border_spacing, LayoutBorderSpacingValue, BorderSpacing, as_border_spacing);
    impl_get_prop!(get_caption_side, StyleCaptionSideValue, CaptionSide, as_caption_side);
    impl_get_prop!(get_empty_cells, StyleEmptyCellsValue, EmptyCells, as_empty_cells);

    // Width calculation methods
    pub fn calc_width(
        &self,
        node_data: &NodeData,
        node_id: &NodeId,
        styled_node_state: &StyledNodeState,
        reference_width: f32,
    ) -> f32 {
        self.get_width(node_data, node_id, styled_node_state)
            .and_then(|w| match w.get_property()? {
                LayoutWidth::Px(px) => Some(px.to_pixels_internal(
                    reference_width,
                    azul_css::props::basic::pixel::DEFAULT_FONT_SIZE,
                    azul_css::props::basic::pixel::DEFAULT_FONT_SIZE,
                )),
                _ => Some(0.0), // min-content/max-content not resolved here
            })
            .unwrap_or(0.0)
    }

    pub fn calc_min_width(
        &self,
        node_data: &NodeData,
        node_id: &NodeId,
        styled_node_state: &StyledNodeState,
        reference_width: f32,
    ) -> f32 {
        self.get_min_width(node_data, node_id, styled_node_state)
            .and_then(|w| {
                Some(w.get_property()?.inner.to_pixels_internal(
                    reference_width,
                    azul_css::props::basic::pixel::DEFAULT_FONT_SIZE,
                    azul_css::props::basic::pixel::DEFAULT_FONT_SIZE,
                ))
            })
            .unwrap_or(0.0)
    }

    pub fn calc_max_width(
        &self,
        node_data: &NodeData,
        node_id: &NodeId,
        styled_node_state: &StyledNodeState,
        reference_width: f32,
    ) -> Option<f32> {
        self.get_max_width(node_data, node_id, styled_node_state)
            .and_then(|w| {
                Some(w.get_property()?.inner.to_pixels_internal(
                    reference_width,
                    azul_css::props::basic::pixel::DEFAULT_FONT_SIZE,
                    azul_css::props::basic::pixel::DEFAULT_FONT_SIZE,
                ))
            })
    }

    // Height calculation methods
    pub fn calc_height(
        &self,
        node_data: &NodeData,
        node_id: &NodeId,
        styled_node_state: &StyledNodeState,
        reference_height: f32,
    ) -> f32 {
        self.get_height(node_data, node_id, styled_node_state)
            .and_then(|h| match h.get_property()? {
                LayoutHeight::Px(px) => Some(px.to_pixels_internal(
                    reference_height,
                    azul_css::props::basic::pixel::DEFAULT_FONT_SIZE,
                    azul_css::props::basic::pixel::DEFAULT_FONT_SIZE,
                )),
                _ => Some(0.0), // min-content/max-content not resolved here
            })
            .unwrap_or(0.0)
    }

    pub fn calc_min_height(
        &self,
        node_data: &NodeData,
        node_id: &NodeId,
        styled_node_state: &StyledNodeState,
        reference_height: f32,
    ) -> f32 {
        self.get_min_height(node_data, node_id, styled_node_state)
            .and_then(|h| {
                Some(h.get_property()?.inner.to_pixels_internal(
                    reference_height,
                    azul_css::props::basic::pixel::DEFAULT_FONT_SIZE,
                    azul_css::props::basic::pixel::DEFAULT_FONT_SIZE,
                ))
            })
            .unwrap_or(0.0)
    }

    pub fn calc_max_height(
        &self,
        node_data: &NodeData,
        node_id: &NodeId,
        styled_node_state: &StyledNodeState,
        reference_height: f32,
    ) -> Option<f32> {
        self.get_max_height(node_data, node_id, styled_node_state)
            .and_then(|h| {
                Some(h.get_property()?.inner.to_pixels_internal(
                    reference_height,
                    azul_css::props::basic::pixel::DEFAULT_FONT_SIZE,
                    azul_css::props::basic::pixel::DEFAULT_FONT_SIZE,
                ))
            })
    }

    // Position calculation methods
    pub fn calc_left(
        &self,
        node_data: &NodeData,
        node_id: &NodeId,
        styled_node_state: &StyledNodeState,
        reference_width: f32,
    ) -> Option<f32> {
        self.get_left(node_data, node_id, styled_node_state)
            .and_then(|l| {
                Some(l.get_property()?.inner.to_pixels_internal(
                    reference_width,
                    azul_css::props::basic::pixel::DEFAULT_FONT_SIZE,
                    azul_css::props::basic::pixel::DEFAULT_FONT_SIZE,
                ))
            })
    }

    pub fn calc_right(
        &self,
        node_data: &NodeData,
        node_id: &NodeId,
        styled_node_state: &StyledNodeState,
        reference_width: f32,
    ) -> Option<f32> {
        self.get_right(node_data, node_id, styled_node_state)
            .and_then(|r| {
                Some(r.get_property()?.inner.to_pixels_internal(
                    reference_width,
                    azul_css::props::basic::pixel::DEFAULT_FONT_SIZE,
                    azul_css::props::basic::pixel::DEFAULT_FONT_SIZE,
                ))
            })
    }

    pub fn calc_top(
        &self,
        node_data: &NodeData,
        node_id: &NodeId,
        styled_node_state: &StyledNodeState,
        reference_height: f32,
    ) -> Option<f32> {
        self.get_top(node_data, node_id, styled_node_state)
            .and_then(|t| {
                Some(t.get_property()?.inner.to_pixels_internal(
                    reference_height,
                    azul_css::props::basic::pixel::DEFAULT_FONT_SIZE,
                    azul_css::props::basic::pixel::DEFAULT_FONT_SIZE,
                ))
            })
    }

    pub fn calc_bottom(
        &self,
        node_data: &NodeData,
        node_id: &NodeId,
        styled_node_state: &StyledNodeState,
        reference_height: f32,
    ) -> Option<f32> {
        self.get_bottom(node_data, node_id, styled_node_state)
            .and_then(|b| {
                Some(b.get_property()?.inner.to_pixels_internal(
                    reference_height,
                    azul_css::props::basic::pixel::DEFAULT_FONT_SIZE,
                    azul_css::props::basic::pixel::DEFAULT_FONT_SIZE,
                ))
            })
    }

    // Border calculation methods
    pub fn calc_border_left_width(
        &self,
        node_data: &NodeData,
        node_id: &NodeId,
        styled_node_state: &StyledNodeState,
        reference_width: f32,
    ) -> f32 {
        self.get_border_left_width(node_data, node_id, styled_node_state)
            .and_then(|b| {
                Some(b.get_property()?.inner.to_pixels_internal(
                    reference_width,
                    azul_css::props::basic::pixel::DEFAULT_FONT_SIZE,
                    azul_css::props::basic::pixel::DEFAULT_FONT_SIZE,
                ))
            })
            .unwrap_or(0.0)
    }

    pub fn calc_border_right_width(
        &self,
        node_data: &NodeData,
        node_id: &NodeId,
        styled_node_state: &StyledNodeState,
        reference_width: f32,
    ) -> f32 {
        self.get_border_right_width(node_data, node_id, styled_node_state)
            .and_then(|b| {
                Some(b.get_property()?.inner.to_pixels_internal(
                    reference_width,
                    azul_css::props::basic::pixel::DEFAULT_FONT_SIZE,
                    azul_css::props::basic::pixel::DEFAULT_FONT_SIZE,
                ))
            })
            .unwrap_or(0.0)
    }

    pub fn calc_border_top_width(
        &self,
        node_data: &NodeData,
        node_id: &NodeId,
        styled_node_state: &StyledNodeState,
        reference_height: f32,
    ) -> f32 {
        self.get_border_top_width(node_data, node_id, styled_node_state)
            .and_then(|b| {
                Some(b.get_property()?.inner.to_pixels_internal(
                    reference_height,
                    azul_css::props::basic::pixel::DEFAULT_FONT_SIZE,
                    azul_css::props::basic::pixel::DEFAULT_FONT_SIZE,
                ))
            })
            .unwrap_or(0.0)
    }

    pub fn calc_border_bottom_width(
        &self,
        node_data: &NodeData,
        node_id: &NodeId,
        styled_node_state: &StyledNodeState,
        reference_height: f32,
    ) -> f32 {
        self.get_border_bottom_width(node_data, node_id, styled_node_state)
            .and_then(|b| {
                Some(b.get_property()?.inner.to_pixels_internal(
                    reference_height,
                    azul_css::props::basic::pixel::DEFAULT_FONT_SIZE,
                    azul_css::props::basic::pixel::DEFAULT_FONT_SIZE,
                ))
            })
            .unwrap_or(0.0)
    }

    // Padding calculation methods
    pub fn calc_padding_left(
        &self,
        node_data: &NodeData,
        node_id: &NodeId,
        styled_node_state: &StyledNodeState,
        reference_width: f32,
    ) -> f32 {
        self.get_padding_left(node_data, node_id, styled_node_state)
            .and_then(|p| {
                Some(p.get_property()?.inner.to_pixels_internal(
                    reference_width,
                    azul_css::props::basic::pixel::DEFAULT_FONT_SIZE,
                    azul_css::props::basic::pixel::DEFAULT_FONT_SIZE,
                ))
            })
            .unwrap_or(0.0)
    }

    pub fn calc_padding_right(
        &self,
        node_data: &NodeData,
        node_id: &NodeId,
        styled_node_state: &StyledNodeState,
        reference_width: f32,
    ) -> f32 {
        self.get_padding_right(node_data, node_id, styled_node_state)
            .and_then(|p| {
                Some(p.get_property()?.inner.to_pixels_internal(
                    reference_width,
                    azul_css::props::basic::pixel::DEFAULT_FONT_SIZE,
                    azul_css::props::basic::pixel::DEFAULT_FONT_SIZE,
                ))
            })
            .unwrap_or(0.0)
    }

    pub fn calc_padding_top(
        &self,
        node_data: &NodeData,
        node_id: &NodeId,
        styled_node_state: &StyledNodeState,
        reference_height: f32,
    ) -> f32 {
        self.get_padding_top(node_data, node_id, styled_node_state)
            .and_then(|p| {
                Some(p.get_property()?.inner.to_pixels_internal(
                    reference_height,
                    azul_css::props::basic::pixel::DEFAULT_FONT_SIZE,
                    azul_css::props::basic::pixel::DEFAULT_FONT_SIZE,
                ))
            })
            .unwrap_or(0.0)
    }

    pub fn calc_padding_bottom(
        &self,
        node_data: &NodeData,
        node_id: &NodeId,
        styled_node_state: &StyledNodeState,
        reference_height: f32,
    ) -> f32 {
        self.get_padding_bottom(node_data, node_id, styled_node_state)
            .and_then(|p| {
                Some(p.get_property()?.inner.to_pixels_internal(
                    reference_height,
                    azul_css::props::basic::pixel::DEFAULT_FONT_SIZE,
                    azul_css::props::basic::pixel::DEFAULT_FONT_SIZE,
                ))
            })
            .unwrap_or(0.0)
    }

    // Margin calculation methods
    pub fn calc_margin_left(
        &self,
        node_data: &NodeData,
        node_id: &NodeId,
        styled_node_state: &StyledNodeState,
        reference_width: f32,
    ) -> f32 {
        self.get_margin_left(node_data, node_id, styled_node_state)
            .and_then(|m| {
                Some(m.get_property()?.inner.to_pixels_internal(
                    reference_width,
                    azul_css::props::basic::pixel::DEFAULT_FONT_SIZE,
                    azul_css::props::basic::pixel::DEFAULT_FONT_SIZE,
                ))
            })
            .unwrap_or(0.0)
    }

    pub fn calc_margin_right(
        &self,
        node_data: &NodeData,
        node_id: &NodeId,
        styled_node_state: &StyledNodeState,
        reference_width: f32,
    ) -> f32 {
        self.get_margin_right(node_data, node_id, styled_node_state)
            .and_then(|m| {
                Some(m.get_property()?.inner.to_pixels_internal(
                    reference_width,
                    azul_css::props::basic::pixel::DEFAULT_FONT_SIZE,
                    azul_css::props::basic::pixel::DEFAULT_FONT_SIZE,
                ))
            })
            .unwrap_or(0.0)
    }

    pub fn calc_margin_top(
        &self,
        node_data: &NodeData,
        node_id: &NodeId,
        styled_node_state: &StyledNodeState,
        reference_height: f32,
    ) -> f32 {
        self.get_margin_top(node_data, node_id, styled_node_state)
            .and_then(|m| {
                Some(m.get_property()?.inner.to_pixels_internal(
                    reference_height,
                    azul_css::props::basic::pixel::DEFAULT_FONT_SIZE,
                    azul_css::props::basic::pixel::DEFAULT_FONT_SIZE,
                ))
            })
            .unwrap_or(0.0)
    }

    pub fn calc_margin_bottom(
        &self,
        node_data: &NodeData,
        node_id: &NodeId,
        styled_node_state: &StyledNodeState,
        reference_height: f32,
    ) -> f32 {
        self.get_margin_bottom(node_data, node_id, styled_node_state)
            .and_then(|m| {
                Some(m.get_property()?.inner.to_pixels_internal(
                    reference_height,
                    azul_css::props::basic::pixel::DEFAULT_FONT_SIZE,
                    azul_css::props::basic::pixel::DEFAULT_FONT_SIZE,
                ))
            })
            .unwrap_or(0.0)
    }

    #[allow(clippy::too_many_lines)] // large but cohesive: single-purpose parser/builder/dispatch (one branch per input variant)
    fn resolve_property_dependency(
        target_property: &CssProperty,
        reference_property: &CssProperty,
    ) -> Option<CssProperty> {
        // wildcard import: this big property-dispatch match references the full set
        // of layout property types; enumerating them all is unmaintainable.
        #[allow(clippy::wildcard_imports)]
        use azul_css::{
            css::CssPropertyValue,
            props::{
                basic::{font::StyleFontSize, length::SizeMetric, pixel::PixelValue},
                layout::*,
                style::{SelectionRadius, StyleLetterSpacing, StyleWordSpacing},
            },
        };

        // Extract PixelValue from various property types (returns owned value)
        let get_pixel_value = |prop: &CssProperty| -> Option<PixelValue> {
            match prop {
                CssProperty::FontSize(val) => val.get_property().map(|v| v.inner),
                CssProperty::LetterSpacing(val) => val.get_property().map(|v| v.inner),
                CssProperty::WordSpacing(val) => val.get_property().map(|v| v.inner),
                CssProperty::PaddingLeft(val) => val.get_property().map(|v| v.inner),
                CssProperty::PaddingRight(val) => val.get_property().map(|v| v.inner),
                CssProperty::PaddingTop(val) => val.get_property().map(|v| v.inner),
                CssProperty::PaddingBottom(val) => val.get_property().map(|v| v.inner),
                CssProperty::MarginLeft(val) => val.get_property().map(|v| v.inner),
                CssProperty::MarginRight(val) => val.get_property().map(|v| v.inner),
                CssProperty::MarginTop(val) => val.get_property().map(|v| v.inner),
                CssProperty::MarginBottom(val) => val.get_property().map(|v| v.inner),
                CssProperty::MinWidth(val) => val.get_property().map(|v| v.inner),
                CssProperty::MinHeight(val) => val.get_property().map(|v| v.inner),
                CssProperty::MaxWidth(val) => val.get_property().map(|v| v.inner),
                CssProperty::MaxHeight(val) => val.get_property().map(|v| v.inner),
                CssProperty::SelectionRadius(val) => val.get_property().map(|v| v.inner),
                _ => None,
            }
        };

        let target_pixel_value = get_pixel_value(target_property)?;
        let reference_pixel_value = get_pixel_value(reference_property)?;

        // Convert reference to absolute pixels first
        let reference_px = match reference_pixel_value.metric {
            SizeMetric::Px => reference_pixel_value.number.get(),
            SizeMetric::Pt => reference_pixel_value.number.get() * PT_TO_PX,
            SizeMetric::In => reference_pixel_value.number.get() * IN_TO_PX,
            SizeMetric::Cm => reference_pixel_value.number.get() * CM_TO_PX,
            SizeMetric::Mm => reference_pixel_value.number.get() * MM_TO_PX,
            // Reference can't be relative (em/rem/%) or viewport-relative.
            SizeMetric::Em
            | SizeMetric::Rem
            | SizeMetric::Percent
            | SizeMetric::Vw
            | SizeMetric::Vh
            | SizeMetric::Vmin
            | SizeMetric::Vmax => return None,
        };

        // Resolve target based on reference
        let resolved_px = match target_pixel_value.metric {
            SizeMetric::Px => target_pixel_value.number.get(),
            SizeMetric::Pt => target_pixel_value.number.get() * PT_TO_PX,
            SizeMetric::In => target_pixel_value.number.get() * IN_TO_PX,
            SizeMetric::Cm => target_pixel_value.number.get() * CM_TO_PX,
            SizeMetric::Mm => target_pixel_value.number.get() * MM_TO_PX,
            // em/rem both scale by reference (rem uses reference as root font-size).
            SizeMetric::Em | SizeMetric::Rem => target_pixel_value.number.get() * reference_px,
            SizeMetric::Percent => target_pixel_value.number.get() / 100.0 * reference_px,
            // Need viewport context
            SizeMetric::Vw | SizeMetric::Vh | SizeMetric::Vmin | SizeMetric::Vmax => return None,
        };

        // Create a new property with the resolved value
        let resolved_pixel_value = PixelValue::px(resolved_px);

        match target_property {
            CssProperty::FontSize(_) => Some(CssProperty::FontSize(CssPropertyValue::Exact(
                StyleFontSize {
                    inner: resolved_pixel_value,
                },
            ))),
            CssProperty::LetterSpacing(_) => Some(CssProperty::LetterSpacing(
                CssPropertyValue::Exact(StyleLetterSpacing {
                    inner: resolved_pixel_value,
                }),
            )),
            CssProperty::WordSpacing(_) => Some(CssProperty::WordSpacing(CssPropertyValue::Exact(
                StyleWordSpacing {
                    inner: resolved_pixel_value,
                },
            ))),
            CssProperty::PaddingLeft(_) => Some(CssProperty::PaddingLeft(CssPropertyValue::Exact(
                LayoutPaddingLeft {
                    inner: resolved_pixel_value,
                },
            ))),
            CssProperty::PaddingRight(_) => Some(CssProperty::PaddingRight(
                CssPropertyValue::Exact(LayoutPaddingRight {
                    inner: resolved_pixel_value,
                }),
            )),
            CssProperty::PaddingTop(_) => Some(CssProperty::PaddingTop(CssPropertyValue::Exact(
                LayoutPaddingTop {
                    inner: resolved_pixel_value,
                },
            ))),
            CssProperty::PaddingBottom(_) => Some(CssProperty::PaddingBottom(
                CssPropertyValue::Exact(LayoutPaddingBottom {
                    inner: resolved_pixel_value,
                }),
            )),
            CssProperty::MarginLeft(_) => Some(CssProperty::MarginLeft(CssPropertyValue::Exact(
                LayoutMarginLeft {
                    inner: resolved_pixel_value,
                },
            ))),
            CssProperty::MarginRight(_) => Some(CssProperty::MarginRight(CssPropertyValue::Exact(
                LayoutMarginRight {
                    inner: resolved_pixel_value,
                },
            ))),
            CssProperty::MarginTop(_) => Some(CssProperty::MarginTop(CssPropertyValue::Exact(
                LayoutMarginTop {
                    inner: resolved_pixel_value,
                },
            ))),
            CssProperty::MarginBottom(_) => Some(CssProperty::MarginBottom(
                CssPropertyValue::Exact(LayoutMarginBottom {
                    inner: resolved_pixel_value,
                }),
            )),
            CssProperty::MinWidth(_) => Some(CssProperty::MinWidth(CssPropertyValue::Exact(
                LayoutMinWidth {
                    inner: resolved_pixel_value,
                },
            ))),
            CssProperty::MinHeight(_) => Some(CssProperty::MinHeight(CssPropertyValue::Exact(
                LayoutMinHeight {
                    inner: resolved_pixel_value,
                },
            ))),
            CssProperty::MaxWidth(_) => Some(CssProperty::MaxWidth(CssPropertyValue::Exact(
                LayoutMaxWidth {
                    inner: resolved_pixel_value,
                },
            ))),
            CssProperty::MaxHeight(_) => Some(CssProperty::MaxHeight(CssPropertyValue::Exact(
                LayoutMaxHeight {
                    inner: resolved_pixel_value,
                },
            ))),
            CssProperty::SelectionRadius(_) => Some(CssProperty::SelectionRadius(
                CssPropertyValue::Exact(SelectionRadius {
                    inner: resolved_pixel_value,
                }),
            )),
            _ => None,
        }
    }

    /// Applies user-agent (UA) CSS properties to the cascade before inheritance.
    ///
    /// UA CSS has the lowest priority in the cascade, so it should only be applied
    /// if the node doesn't already have the property from inline styles or author CSS.
    ///
    /// This is critical for text nodes: UA CSS properties (like font-weight: bold for H1)
    /// must be in the cascade maps so they can be inherited by child text nodes.
    ///
    /// Uses a bitset per node to avoid O(n²) scanning of property vecs.
    pub fn apply_ua_css(&mut self, node_data: &[NodeData]) {
        use azul_css::props::property::CssPropertyType;
        use azul_css::dynamic_selector::PseudoStateType;

        let node_count = node_data.len();
        if node_count == 0 {
            return;
        }

        // Build a bitset per node: which CssPropertyType values are already set (Normal state).
        // CssPropertyType has ~178 variants, so we need [u128; 2] per node (256 bits).
        let mut prop_set: Vec<[u128; 2]> = vec![[0u128; 2]; node_count];

        // Mark properties from css_props (author CSS, Normal state)
        for (node_idx, props) in self.css_props.iter_node_slices() {
            for p in props {
                if p.state == PseudoStateType::Normal {
                    let d = p.prop_type as u16 as usize;
                    if d < 128 {
                        prop_set[node_idx][0] |= 1u128 << d;
                    } else {
                        prop_set[node_idx][1] |= 1u128 << (d - 128);
                    }
                }
            }
        }

        // Mark properties from cascaded_props (Normal state)
        for (node_idx, props) in self.cascaded_props.iter_node_slices() {
            for p in props {
                if p.state == PseudoStateType::Normal {
                    let d = p.prop_type as u16 as usize;
                    if d < 128 {
                        prop_set[node_idx][0] |= 1u128 << d;
                    } else {
                        prop_set[node_idx][1] |= 1u128 << (d - 128);
                    }
                }
            }
        }

        // Mark properties from inline CSS (NodeData.style, unconditional = Normal)
        for (node_idx, node) in node_data.iter().enumerate() {
            for (prop, conds) in node.style.iter_inline_properties() {
                let is_normal = conds.as_slice().is_empty();
                if is_normal {
                    let d = prop.get_type() as u16 as usize;
                    if d < 128 {
                        prop_set[node_idx][0] |= 1u128 << d;
                    } else {
                        prop_set[node_idx][1] |= 1u128 << (d - 128);
                    }
                }
            }
        }

        // All UA property types that get_ua_property() may return Some for
        let property_types = [
            CssPropertyType::Display,
            CssPropertyType::Width,
            CssPropertyType::Height,
            CssPropertyType::FontSize,
            CssPropertyType::FontWeight,
            CssPropertyType::FontFamily,
            CssPropertyType::MarginTop,
            CssPropertyType::MarginBottom,
            CssPropertyType::MarginLeft,
            CssPropertyType::MarginRight,
            CssPropertyType::PaddingTop,
            CssPropertyType::PaddingBottom,
            CssPropertyType::PaddingLeft,
            CssPropertyType::PaddingRight,
            CssPropertyType::BorderTopStyle,
            CssPropertyType::BorderTopWidth,
            CssPropertyType::BorderTopColor,
            CssPropertyType::BreakInside,
            CssPropertyType::BreakAfter,
            CssPropertyType::ListStyleType,
            CssPropertyType::CounterReset,
            CssPropertyType::TextDecoration,
            CssPropertyType::TextAlign,
            CssPropertyType::VerticalAlign,
            CssPropertyType::Cursor,
        ];

        // Apply UA CSS: only insert for property types not yet set (bitset check = O(1))
        for (node_index, node) in node_data.iter().enumerate() {
            let node_type = &node.node_type;

            for prop_type in &property_types {
                // Check bitset: if already set, skip entirely
                let d = *prop_type as u16 as usize;
                let has_prop = if d < 128 {
                    (prop_set[node_index][0] & (1u128 << d)) != 0
                } else {
                    (prop_set[node_index][1] & (1u128 << (d - 128))) != 0
                };

                if has_prop {
                    continue;
                }

                // Check if UA CSS defines this property for this node type
                if let Some(ua_prop) = crate::ua_css::get_ua_property(node_type, *prop_type) {
                    self.cascaded_props.push_to(node_index, StatefulCssProperty {
                        state: PseudoStateType::Normal,
                        prop_type: *prop_type,
                        property: ua_prop.clone(),
                    });

                    // Mark as set in the bitset (prevent duplicate insertion for same node)
                    if d < 128 {
                        prop_set[node_index][0] |= 1u128 << d;
                    } else {
                        prop_set[node_index][1] |= 1u128 << (d - 128);
                    }
                }
            }
        }
    }

    /// Sort `cascaded_props` by (state, `prop_type`) and flatten into contiguous memory.
    /// Must be called after `apply_ua_css()` which adds entries to `cascaded_props`.
    pub fn sort_cascaded_props(&mut self) {
        self.cascaded_props.sort_each_and_flatten(|p| (p.state, p.prop_type));
    }

    /// Compute inherited values for all nodes in the DOM tree.
    ///
    /// Implements CSS inheritance: walk tree depth-first, apply cascade priority
    /// (inherited → cascaded → css → inline → user), create dependency chains for
    /// relative values. Call `apply_ua_css()` before this function.
    pub fn compute_inherited_values(
        &mut self,
        node_hierarchy: &[NodeHierarchyItem],
        node_data: &[NodeData],
    ) -> Vec<NodeId> {
        if self.computed_values.len() < node_hierarchy.len() {
            self.computed_values.resize(node_hierarchy.len(), Vec::new());
        }
        node_hierarchy
            .iter()
            .enumerate()
            .filter_map(|(node_index, hierarchy_item)| {
                let node_id = NodeId::new(node_index);
                let parent_id = hierarchy_item.parent_id();
                let parent_computed: Option<Vec<(CssPropertyType, CssPropertyWithOrigin)>> =
                    parent_id.and_then(|pid| self.computed_values.get(pid.index()).cloned());

                let mut ctx = InheritanceContext {
                    node_id,
                    parent_id,
                    computed_values: Vec::new(),
                };

                // Step 1: Inherit from parent
                if let Some(ref parent_values) = parent_computed {
                    Self::inherit_from_parent(&mut ctx, parent_values);
                }

                // Steps 2-5: Apply cascade in priority order
                self.apply_cascade_properties(
                    &mut ctx,
                    node_id,
                    parent_computed.as_ref(),
                    node_data,
                    node_index,
                );

                // Check for changes and store
                let changed = self.store_if_changed(&ctx);
                changed.then_some(node_id)
            })
            .collect()
    }

    /// Inherit inheritable properties from parent node
    fn inherit_from_parent(
        ctx: &mut InheritanceContext,
        parent_values: &[(CssPropertyType, CssPropertyWithOrigin)],
    ) {
        for (prop_type, prop_with_origin) in
            parent_values.iter().filter(|(pt, _)| pt.is_inheritable())
        {
            let entry = (*prop_type, CssPropertyWithOrigin {
                property: prop_with_origin.property.clone(),
                origin: CssPropertyOrigin::Inherited,
            });
            // Insert into sorted vec
            match ctx.computed_values.binary_search_by_key(prop_type, |(k, _)| *k) {
                Ok(idx) => ctx.computed_values[idx] = entry,
                Err(idx) => ctx.computed_values.insert(idx, entry),
            }
        }
    }

    /// Apply all cascade properties in priority order
    fn apply_cascade_properties(
        &self,
        ctx: &mut InheritanceContext,
        node_id: NodeId,
        parent_computed: Option<&Vec<(CssPropertyType, CssPropertyWithOrigin)>>,
        node_data: &[NodeData],
        node_index: usize,
    ) {
        // Step 2: Cascaded properties (UA CSS)
        {
            let cascaded_slice = self.cascaded_props.get_slice(node_id.index());
            for p in cascaded_slice {
                if p.state == azul_css::dynamic_selector::PseudoStateType::Normal
                    && Self::should_apply_cascaded(&ctx.computed_values, p.prop_type, &p.property) {
                        Self::process_property(ctx, &p.property, parent_computed);
                    }
            }
        }

        // Step 3: CSS properties (stylesheets)
        {
            let css_slice = self.css_props.get_slice(node_id.index());
            for p in css_slice {
                if p.state == azul_css::dynamic_selector::PseudoStateType::Normal {
                    Self::process_property(ctx, &p.property, parent_computed);
                }
            }
        }

        // Step 4: Inline CSS properties
        for (prop, conds) in node_data[node_index].style.iter_inline_properties() {
            // Only apply unconditional (normal) properties
            if conds.as_slice().is_empty() {
                Self::process_property(ctx, prop, parent_computed);
            }
        }

        // Step 5: User-overridden properties
        if let Some(user_props) = self.user_overridden_properties.get(node_id.index()) {
            for (_, prop) in user_props {
                Self::process_property(ctx, prop, parent_computed);
            }
        }
    }

    /// Check if a cascaded property should be applied.
    ///
    /// A cascaded (UA / author-selector) value applies unless the node has
    /// already set its OWN value (`origin == Own`), which wins per the cascade.
    /// An `Inherited` placeholder must NOT block it — including a relative
    /// `font-size`: an earlier version skipped a cascaded relative font-size when
    /// an inherited value existed, which silently dropped `<h1>`'s UA
    /// `font-size: 2em` (and every heading), leaving headings at their parent's
    /// size. That was wrong: `resolve_font_size_property` resolves the `em`
    /// against the *parent's* font-size, not the inherited value, so there is no
    /// double-scaling — the cascaded relative size must apply and overwrite the
    /// inherited entry.
    fn should_apply_cascaded(
        computed: &[(CssPropertyType, CssPropertyWithOrigin)],
        prop_type: CssPropertyType,
        _prop: &CssProperty,
    ) -> bool {
        computed
            .binary_search_by_key(&prop_type, |(k, _)| *k)
            .map_or(true, |idx| computed[idx].1.origin == CssPropertyOrigin::Inherited)
    }

    /// Process a single property: resolve and store
    fn process_property(
        ctx: &mut InheritanceContext,
        prop: &CssProperty,
        parent_computed: Option<&Vec<(CssPropertyType, CssPropertyWithOrigin)>>,
    ) {
        let prop_type = prop.get_type();

        let resolved = if prop_type == CssPropertyType::FontSize {
            Self::resolve_font_size_property(prop, parent_computed)
        } else {
            Self::resolve_other_property(prop, &ctx.computed_values)
        };

        let entry = (prop_type, CssPropertyWithOrigin {
            property: resolved,
            origin: CssPropertyOrigin::Own,
        });
        match ctx.computed_values.binary_search_by_key(&prop_type, |(k, _)| *k) {
            Ok(idx) => ctx.computed_values[idx] = entry,
            Err(idx) => ctx.computed_values.insert(idx, entry),
        }
    }

    /// Resolve font-size property (uses parent's font-size as reference)
    fn resolve_font_size_property(
        prop: &CssProperty,
        parent_computed: Option<&Vec<(CssPropertyType, CssPropertyWithOrigin)>>,
    ) -> CssProperty {
        let parent_font_size = parent_computed
            .and_then(|p| {
                p.binary_search_by_key(&CssPropertyType::FontSize, |(k, _)| *k)
                    .ok()
                    .map(|idx| &p[idx].1)
            });

        parent_font_size.map_or_else(|| Self::resolve_font_size_to_pixels(
                prop,
                azul_css::props::basic::pixel::DEFAULT_FONT_SIZE,
            ), |pfs| Self::resolve_property_dependency(prop, &pfs.property).unwrap_or_else(
                || {
                    Self::resolve_font_size_to_pixels(
                        prop,
                        azul_css::props::basic::pixel::DEFAULT_FONT_SIZE,
                    )
                },
            ))
    }

    /// Resolve other properties (uses current node's font-size as reference)
    fn resolve_other_property(
        prop: &CssProperty,
        computed: &[(CssPropertyType, CssPropertyWithOrigin)],
    ) -> CssProperty {
        computed
            .binary_search_by_key(&CssPropertyType::FontSize, |(k, _)| *k)
            .ok()
            .and_then(|idx| Self::resolve_property_dependency(prop, &computed[idx].1.property))
            .unwrap_or_else(|| prop.clone())
    }

    /// Convert font-size to absolute pixels
    fn resolve_font_size_to_pixels(prop: &CssProperty, reference_px: f32) -> CssProperty {
        use azul_css::{
            css::CssPropertyValue,
            props::basic::{font::StyleFontSize, length::SizeMetric, pixel::PixelValue},
        };

        let CssProperty::FontSize(css_val) = prop else {
            return prop.clone();
        };

        let Some(font_size) = css_val.get_property() else {
            return prop.clone();
        };

        let resolved_px = match font_size.inner.metric {
            SizeMetric::Px => font_size.inner.number.get(),
            SizeMetric::Pt => font_size.inner.number.get() * PT_TO_PX,
            SizeMetric::In => font_size.inner.number.get() * IN_TO_PX,
            SizeMetric::Cm => font_size.inner.number.get() * CM_TO_PX,
            SizeMetric::Mm => font_size.inner.number.get() * MM_TO_PX,
            SizeMetric::Em => font_size.inner.number.get() * reference_px,
            SizeMetric::Rem => {
                font_size.inner.number.get() * azul_css::props::basic::pixel::DEFAULT_FONT_SIZE
            }
            SizeMetric::Percent => font_size.inner.number.get() / 100.0 * reference_px,
            SizeMetric::Vw | SizeMetric::Vh | SizeMetric::Vmin | SizeMetric::Vmax => {
                return prop.clone();
            }
        };

        CssProperty::FontSize(CssPropertyValue::Exact(StyleFontSize {
            inner: PixelValue::px(resolved_px),
        }))
    }

    /// Check if font-size has relative unit (em, rem, %)
    fn has_relative_font_size_unit(prop: &CssProperty) -> bool {
        use azul_css::props::basic::length::SizeMetric;

        let CssProperty::FontSize(css_val) = prop else {
            return false;
        };

        css_val
            .get_property()
            .is_some_and(|fs| {
                matches!(
                    fs.inner.metric,
                    SizeMetric::Em | SizeMetric::Rem | SizeMetric::Percent
                )
            })
    }

    /// Store computed values if changed, returns true if values were updated
    fn store_if_changed(&mut self, ctx: &InheritanceContext) -> bool {
        let values_changed = self
            .computed_values
            .get(ctx.node_id.index()) != Some(&ctx.computed_values);

        self.computed_values[ctx.node_id.index()].clone_from(&ctx.computed_values);

        values_changed
    }
}

/// Context for computing inherited values for a single node
struct InheritanceContext {
    node_id: NodeId,
    parent_id: Option<NodeId>,
    computed_values: Vec<(CssPropertyType, CssPropertyWithOrigin)>,
}

impl CssPropertyCache {

    /// Clear the entire compact cache. Call after major DOM changes.
    pub(crate) fn invalidate_resolved_cache(&mut self) {
        self.compact_cache = None;
    }
}

#[cfg(test)]
#[allow(clippy::float_cmp, clippy::too_many_lines)]
mod autotest_generated {
    use azul_css::{
        css::CssPropertyValue,
        dynamic_selector::{
            CssPropertyWithConditions, DynamicSelector, DynamicSelectorContext, PseudoStateType,
        },
        props::{
            basic::{length::SizeMetric, pixel::PixelValue},
            layout::{
                LayoutFlexBasis, LayoutInsetBottom, LayoutLeft, LayoutMarginTop, LayoutMaxWidth,
                LayoutMinWidth, LayoutOverflow, LayoutPaddingLeft, LayoutRight, LayoutTop,
            },
            style::LayoutBorderLeftWidth,
        },
    };

    use super::*;

    // ---------------------------------------------------------------------
    // helpers
    // ---------------------------------------------------------------------

    /// Approximate float compare — every value here round-trips through
    /// `FloatValue`'s fixed-point (1/1000) encoding.
    fn close(a: f32, b: f32) -> bool {
        (a - b).abs() < 0.01
    }

    fn n0() -> NodeId {
        NodeId::new(0)
    }

    fn normal() -> StyledNodeState {
        StyledNodeState::default()
    }

    /// A `<div>` carrying `props` as unconditional (Normal-state) inline CSS.
    fn div_with(props: Vec<CssProperty>) -> NodeData {
        let mut nd = NodeData::create_div();
        for property in props {
            nd.add_css_property(CssPropertyWithConditions {
                property,
                apply_if: Vec::new().into(),
            });
        }
        nd
    }

    /// A `<div>` carrying `props` gated on a single pseudo-state.
    fn div_with_pseudo(props: Vec<CssProperty>, state: PseudoStateType) -> NodeData {
        let mut nd = NodeData::create_div();
        for property in props {
            nd.add_css_property(CssPropertyWithConditions {
                property,
                apply_if: vec![DynamicSelector::PseudoState(state)].into(),
            });
        }
        nd
    }

    fn width_px(v: f32) -> CssProperty {
        CssProperty::Width(CssPropertyValue::Exact(LayoutWidth::Px(PixelValue::px(v))))
    }

    fn width_pct(v: f32) -> CssProperty {
        CssProperty::Width(CssPropertyValue::Exact(LayoutWidth::Px(PixelValue::percent(
            v,
        ))))
    }

    fn font_size(pv: PixelValue) -> CssProperty {
        CssProperty::FontSize(CssPropertyValue::Exact(StyleFontSize { inner: pv }))
    }

    /// Pull `(metric, number)` back out of a `CssProperty::FontSize`.
    fn font_size_parts(p: &CssProperty) -> Option<(SizeMetric, f32)> {
        match p {
            CssProperty::FontSize(v) => v
                .get_property()
                .map(|fs| (fs.inner.metric, fs.inner.number.get())),
            _ => None,
        }
    }

    fn stateful(state: PseudoStateType, property: CssProperty) -> StatefulCssProperty {
        StatefulCssProperty {
            state,
            prop_type: property.get_type(),
            property,
        }
    }

    // =====================================================================
    // FlatVecVec — construction / getters / predicates
    // =====================================================================

    #[test]
    fn flatvecvec_new_zero_is_empty() {
        let f = FlatVecVec::<i32>::new(0);
        assert_eq!(f.len(), 0);
        assert!(f.is_empty());
        // Quirk worth pinning: with no build slots at all, `is_flattened()` is
        // vacuously true (`build.is_empty()`), even though `flatten()` never ran.
        assert!(f.is_flattened());
        assert!(f.get_slice(0).is_empty());
    }

    #[test]
    fn flatvecvec_new_invariants_hold() {
        let f = FlatVecVec::<i32>::new(3);
        assert_eq!(f.len(), 3);
        assert!(!f.is_empty());
        assert!(!f.is_flattened(), "fresh multi-slot vec is in build phase");
        assert_eq!(f.build_get(0), Some(&Vec::new()));
        assert_eq!(f.build_get(2), Some(&Vec::new()));
        assert_eq!(f.build_get(3), None, "one past the end");
        assert_eq!(f.build_get(usize::MAX), None);
        assert!(f.get_slice(0).is_empty());
    }

    #[test]
    fn flatvecvec_default_is_neutral() {
        let f = FlatVecVec::<i32>::default();
        assert_eq!(f.len(), 0);
        assert!(f.is_empty());
        assert_eq!(f.build_get(0), None);
        assert!(f.get_slice(0).is_empty());
    }

    #[test]
    fn flatvecvec_get_slice_out_of_bounds_is_empty_in_both_phases() {
        let mut f = FlatVecVec::<i32>::new(2);
        f.push_to(0, 7);
        // build phase
        assert_eq!(f.get_slice(0), &[7]);
        assert!(f.get_slice(2).is_empty());
        assert!(f.get_slice(usize::MAX).is_empty());

        f.flatten();
        // read phase — same out-of-bounds contract, still no panic
        assert_eq!(f.get_slice(0), &[7]);
        assert!(f.get_slice(2).is_empty());
        assert!(f.get_slice(usize::MAX).is_empty());
    }

    #[test]
    #[should_panic(expected = "index out of bounds")]
    fn flatvecvec_push_to_out_of_bounds_panics() {
        // Documented in `push_to`: "Panics if ... node_index >= len()".
        let mut f = FlatVecVec::<i32>::new(1);
        f.push_to(1, 0);
    }

    #[test]
    #[should_panic(expected = "index out of bounds")]
    fn flatvecvec_push_to_after_flatten_panics() {
        // Documented in `push_to`: "Panics if already flattened".
        let mut f = FlatVecVec::<i32>::new(1);
        f.flatten();
        f.push_to(0, 0);
    }

    #[test]
    #[should_panic(expected = "index out of bounds")]
    fn flatvecvec_build_mut_out_of_bounds_panics() {
        let mut f = FlatVecVec::<i32>::new(1);
        let _ = f.build_mut(usize::MAX);
    }

    #[test]
    fn flatvecvec_build_iter_mut_visits_every_slot() {
        let mut f = FlatVecVec::<i32>::new(3);
        f.push_to(0, 1);
        f.push_to(2, 2);
        let mut visited = 0;
        for v in f.build_iter_mut() {
            visited += 1;
            v.clear();
        }
        assert_eq!(visited, 3);
        assert!(f.get_slice(0).is_empty());
        assert!(f.get_slice(2).is_empty());
    }

    #[test]
    fn flatvecvec_build_get_returns_none_once_flattened() {
        let mut f = FlatVecVec::<i32>::new(1);
        f.push_to(0, 5);
        f.flatten();
        // Doc: "During read phase, returns None (use `get_slice` instead)."
        assert_eq!(f.build_get(0), None);
        assert_eq!(f.get_slice(0), &[5]);
    }

    // =====================================================================
    // FlatVecVec — heap_bytes (numeric)
    // =====================================================================

    #[test]
    fn flatvecvec_heap_bytes_zero_and_empty() {
        let f = FlatVecVec::<i32>::default();
        assert_eq!(f.heap_bytes(0), 0, "empty vec, zero element size");
        // All three capacities are 0, so even a nonsensical MAX element size
        // multiplies out to 0 rather than overflowing.
        assert_eq!(f.heap_bytes(usize::MAX), 0);
        assert_eq!(f.heap_bytes(size_of::<i32>()), 0);
    }

    #[test]
    fn flatvecvec_heap_bytes_counts_build_and_flat_storage() {
        let mut f = FlatVecVec::<i32>::new(4);
        // Build-phase slots cost at least the outer Vec headers, even at a
        // per-element size of 0.
        assert!(f.heap_bytes(0) >= 4 * size_of::<Vec<i32>>());

        f.push_to(0, 1);
        f.push_to(0, 2);
        let build_bytes = f.heap_bytes(size_of::<i32>());
        assert!(build_bytes > 0);

        f.flatten();
        // Flat storage accounts for the 2 elements + the 4-entry offset table.
        let flat_bytes = f.heap_bytes(size_of::<i32>());
        assert!(flat_bytes >= 2 * size_of::<i32>() + 4 * size_of::<(u32, u32)>());
    }

    // =====================================================================
    // FlatVecVec — flatten / sort_each_and_flatten
    // =====================================================================

    #[test]
    fn flatvecvec_sort_each_and_flatten_keeps_last_of_equal_keys() {
        // CSS cascade rule: among equal keys, later source order wins.
        let mut f = FlatVecVec::<(i32, i32)>::new(1);
        f.push_to(0, (1, 10));
        f.push_to(0, (1, 20)); // same key, pushed later => must win
        f.push_to(0, (0, 30));
        f.sort_each_and_flatten(|p| p.0);

        assert!(f.is_flattened());
        assert_eq!(f.get_slice(0), &[(0, 30), (1, 20)]);
    }

    #[test]
    fn flatvecvec_sort_each_and_flatten_on_empty_slots() {
        let mut f = FlatVecVec::<i32>::new(3);
        f.push_to(1, 42);
        f.sort_each_and_flatten(|v| *v);
        assert_eq!(f.len(), 3);
        assert!(f.get_slice(0).is_empty());
        assert_eq!(f.get_slice(1), &[42]);
        assert!(f.get_slice(2).is_empty());
    }

    #[test]
    fn flatvecvec_sort_each_and_flatten_on_zero_nodes_does_not_panic() {
        let mut f = FlatVecVec::<i32>::new(0);
        f.sort_each_and_flatten(|v| *v);
        assert_eq!(f.len(), 0);
        assert!(f.get_slice(0).is_empty());
    }

    #[test]
    fn flatvecvec_flatten_does_not_deduplicate() {
        let mut f = FlatVecVec::<i32>::new(2);
        f.push_to(0, 5);
        f.push_to(0, 5);
        f.push_to(1, 9);
        f.flatten();
        assert!(f.is_flattened());
        assert_eq!(f.get_slice(0), &[5, 5], "flatten() must not dedup");
        assert_eq!(f.get_slice(1), &[9]);
    }

    // =====================================================================
    // FlatVecVec — retain
    // =====================================================================

    #[test]
    fn flatvecvec_retain_before_flatten_is_a_noop() {
        // Doc: "Must be called after flatten." Before that it must not silently
        // corrupt the build-phase data — it early-returns.
        let mut f = FlatVecVec::<i32>::new(1);
        f.push_to(0, 1);
        f.push_to(0, 2);
        f.retain(|_| false);
        assert_eq!(f.get_slice(0), &[1, 2], "build-phase data left untouched");
    }

    #[test]
    fn flatvecvec_retain_preserves_per_node_order() {
        let mut f = FlatVecVec::<i32>::new(2);
        for v in [1, 2, 3, 4] {
            f.push_to(0, v);
        }
        f.push_to(1, 5);
        f.flatten();

        f.retain(|v| v % 2 == 0);
        assert_eq!(f.get_slice(0), &[2, 4]);
        assert!(f.get_slice(1).is_empty());
        assert_eq!(f.len(), 2, "node slots survive an empty retain");
    }

    #[test]
    fn flatvecvec_retain_dropping_everything_leaves_empty_slices() {
        let mut f = FlatVecVec::<i32>::new(2);
        f.push_to(0, 1);
        f.push_to(1, 2);
        f.flatten();
        f.retain(|_| false);
        assert_eq!(f.len(), 2);
        assert!(f.get_slice(0).is_empty());
        assert!(f.get_slice(1).is_empty());
    }

    #[test]
    fn flatvecvec_retain_with_node_index_sees_owning_node() {
        let mut f = FlatVecVec::<i32>::new(3);
        f.push_to(0, 10);
        f.push_to(1, 11);
        f.push_to(2, 12);
        f.flatten();

        f.retain_with_node_index(|idx, _| idx == 1);
        assert!(f.get_slice(0).is_empty());
        assert_eq!(f.get_slice(1), &[11]);
        assert!(f.get_slice(2).is_empty());
    }

    #[test]
    fn flatvecvec_retain_with_node_index_before_flatten_is_a_noop() {
        let mut f = FlatVecVec::<i32>::new(1);
        f.push_to(0, 1);
        f.retain_with_node_index(|_, _| false);
        assert_eq!(f.get_slice(0), &[1]);
    }

    // =====================================================================
    // FlatVecVec — iteration / extend_from
    // =====================================================================

    #[test]
    fn flatvecvec_iter_node_slices_covers_all_nodes_in_both_phases() {
        let mut f = FlatVecVec::<i32>::new(3);
        f.push_to(1, 7);

        let build: Vec<(usize, Vec<i32>)> = f
            .iter_node_slices()
            .map(|(i, s)| (i, s.to_vec()))
            .collect();
        assert_eq!(build, vec![(0, vec![]), (1, vec![7]), (2, vec![])]);

        f.flatten();
        let flat: Vec<(usize, Vec<i32>)> = f
            .iter_node_slices()
            .map(|(i, s)| (i, s.to_vec()))
            .collect();
        assert_eq!(flat, build, "iteration is phase-independent");
    }

    #[test]
    fn flatvecvec_iter_node_slices_on_empty_yields_nothing() {
        let f = FlatVecVec::<i32>::new(0);
        assert_eq!(f.iter_node_slices().count(), 0);
    }

    #[test]
    fn flatvecvec_extend_from_both_in_build_phase() {
        let mut a = FlatVecVec::<i32>::new(1);
        a.push_to(0, 1);
        let mut b = FlatVecVec::<i32>::new(2);
        b.push_to(0, 2);
        b.push_to(1, 3);

        a.extend_from(&mut b);
        assert_eq!(a.len(), 3);
        assert_eq!(a.get_slice(0), &[1]);
        assert_eq!(a.get_slice(1), &[2]);
        assert_eq!(a.get_slice(2), &[3]);
        assert_eq!(b.len(), 0, "other is drained");
    }

    #[test]
    fn flatvecvec_extend_from_both_flattened_rebases_offsets() {
        let mut a = FlatVecVec::<i32>::new(2);
        a.push_to(0, 1);
        a.push_to(1, 2);
        a.flatten();

        let mut b = FlatVecVec::<i32>::new(2);
        b.push_to(0, 3);
        b.push_to(1, 4);
        b.flatten();

        a.extend_from(&mut b);
        assert_eq!(a.len(), 4);
        assert_eq!(a.get_slice(0), &[1]);
        assert_eq!(a.get_slice(1), &[2]);
        assert_eq!(a.get_slice(2), &[3], "offsets rebased onto a's flat data");
        assert_eq!(a.get_slice(3), &[4]);
    }

    #[test]
    fn flatvecvec_extend_from_across_phases_discards_self_flat_data() {
        // Doc precondition: "Both must be in build phase, or both must be
        // flattened." This pins what a violation actually does today — the
        // flattened side's items are dropped on the floor rather than merged.
        let mut a = FlatVecVec::<i32>::new(1);
        a.push_to(0, 1);
        a.flatten();

        let mut b = FlatVecVec::<i32>::new(1);
        b.push_to(0, 2);

        a.extend_from(&mut b); // no panic...
        assert_eq!(a.len(), 1);
        assert_eq!(
            a.get_slice(0),
            &[2],
            "a's own flattened item (1) is silently lost"
        );
    }

    #[test]
    fn flatvecvec_eq_within_the_same_phase() {
        let mut a = FlatVecVec::<i32>::new(1);
        a.push_to(0, 1);
        let mut b = FlatVecVec::<i32>::new(1);
        b.push_to(0, 1);
        assert_eq!(a, b);

        b.push_to(0, 2);
        assert_ne!(a, b);

        a.flatten();
        // (a and c are both flattened below — equality is only meaningful
        // between two caches in the same phase)
        let mut c = FlatVecVec::<i32>::new(1);
        c.push_to(0, 1);
        c.flatten();
        assert_eq!(a, c);
    }

    // =====================================================================
    // CssPropertyCacheBreakdown
    // =====================================================================

    #[test]
    fn breakdown_total_bytes_sums_subfields_and_excludes_node_count() {
        let b = CssPropertyCacheBreakdown {
            node_count: 999_999,
            cascaded_props_bytes: 1,
            css_props_bytes: 2,
            computed_values_bytes: 4,
            user_overridden_bytes: 8,
            global_css_props_bytes: 16,
            compact_cache_bytes: 32,
            resolved_font_sizes_bytes: 64,
        };
        assert_eq!(b.total_bytes(), 127, "node_count is not a byte count");
    }

    #[test]
    fn breakdown_total_bytes_default_is_zero_and_max_single_field_does_not_overflow() {
        assert_eq!(CssPropertyCacheBreakdown::default().total_bytes(), 0);

        let b = CssPropertyCacheBreakdown {
            cascaded_props_bytes: usize::MAX,
            ..Default::default()
        };
        assert_eq!(b.total_bytes(), usize::MAX);
    }

    // =====================================================================
    // CssPropertyCache — construction / memory / append
    // =====================================================================

    #[test]
    fn cache_empty_zero_is_neutral() {
        let c = CssPropertyCache::empty(0);
        assert_eq!(c.node_count, 0);
        assert!(c.css_props.is_empty());
        assert!(c.cascaded_props.is_empty());
        assert!(c.computed_values.is_empty());
        assert!(c.user_overridden_properties.is_empty());
        assert!(c.global_css_props.is_empty());
        assert!(c.compact_cache.is_none());

        let b = c.memory_breakdown();
        assert_eq!(b.node_count, 0);
        assert_eq!(b.total_bytes(), 0, "a zero-node cache retains no heap");
    }

    #[test]
    fn cache_empty_invariants_hold() {
        let c = CssPropertyCache::empty(7);
        assert_eq!(c.node_count, 7);
        assert_eq!(c.css_props.len(), 7);
        assert_eq!(c.cascaded_props.len(), 7);
        assert!(!c.css_props.is_flattened(), "starts in build phase");
        assert!(c.compact_cache.is_none());

        let b = c.memory_breakdown();
        assert_eq!(b.node_count, 7);
        assert!(b.total_bytes() > 0);
        assert_eq!(b.compact_cache_bytes, 0);
        assert_eq!(b.resolved_font_sizes_bytes, 0);
    }

    #[test]
    fn cache_invalidate_resolved_font_sizes_clears_the_once_lock() {
        let mut c = CssPropertyCache::empty(1);
        assert!(c.resolved_font_sizes_px.set(vec![16.0]).is_ok());
        assert!(c.resolved_font_sizes_px.get().is_some());

        c.invalidate_resolved_font_sizes();
        assert!(
            c.resolved_font_sizes_px.get().is_none(),
            "next read must recompute"
        );
        // and it can be re-populated afterwards
        assert!(c.resolved_font_sizes_px.set(vec![12.0]).is_ok());
    }

    #[test]
    fn cache_append_sums_nodes_and_invalidates_derived_caches() {
        let mut a = CssPropertyCache::empty(2);
        let mut b = CssPropertyCache::empty(3);
        assert!(a.resolved_font_sizes_px.set(vec![16.0, 16.0]).is_ok());

        a.append(&mut b);

        assert_eq!(a.node_count, 5);
        assert_eq!(a.css_props.len(), 5);
        assert_eq!(a.cascaded_props.len(), 5);
        assert!(
            a.resolved_font_sizes_px.get().is_none(),
            "node indices shifted"
        );
        assert!(a.compact_cache.is_none());
    }

    #[test]
    fn cache_append_of_empty_cache_is_a_noop_on_node_count() {
        let mut a = CssPropertyCache::empty(2);
        let mut b = CssPropertyCache::empty(0);
        a.append(&mut b);
        assert_eq!(a.node_count, 2);
        assert_eq!(a.css_props.len(), 2);
    }

    #[test]
    fn cache_invalidate_resolved_cache_drops_compact_cache() {
        let mut c = CssPropertyCache::empty(1);
        c.invalidate_resolved_cache();
        assert!(c.compact_cache.is_none());
    }

    #[test]
    fn cache_ptr_new_and_downcast_roundtrip() {
        let mut p = CssPropertyCachePtr::new(CssPropertyCache::empty(4));
        assert!(p.run_destructor);
        assert_eq!(p.downcast_mut().node_count, 4);

        p.downcast_mut().node_count = 9;
        assert_eq!(p.downcast_mut().node_count, 9, "downcast_mut aliases the box");
    }

    // =====================================================================
    // Predicates (overflow / border / box-shadow)
    // =====================================================================

    #[test]
    fn overflow_predicates_default_to_visible_for_a_bare_div() {
        let c = CssPropertyCache::empty(1);
        let nd = NodeData::create_div();
        assert!(c.is_horizontal_overflow_visible(&nd, &n0(), &normal()));
        assert!(c.is_vertical_overflow_visible(&nd, &n0(), &normal()));
        assert!(!c.is_horizontal_overflow_hidden(&nd, &n0(), &normal()));
        assert!(!c.is_vertical_overflow_hidden(&nd, &n0(), &normal()));
    }

    #[test]
    fn overflow_predicates_are_per_axis() {
        let c = CssPropertyCache::empty(1);
        let nd = div_with(vec![CssProperty::OverflowX(CssPropertyValue::Exact(
            LayoutOverflow::Hidden,
        ))]);
        assert!(c.is_horizontal_overflow_hidden(&nd, &n0(), &normal()));
        assert!(!c.is_horizontal_overflow_visible(&nd, &n0(), &normal()));
        // the Y axis must be untouched
        assert!(!c.is_vertical_overflow_hidden(&nd, &n0(), &normal()));
        assert!(c.is_vertical_overflow_visible(&nd, &n0(), &normal()));
    }

    #[test]
    fn overflow_predicates_do_not_panic_on_an_out_of_range_node_id() {
        let c = CssPropertyCache::empty(0);
        let nd = NodeData::create_div();
        let far = NodeId::new(999_999);
        assert!(c.is_horizontal_overflow_visible(&nd, &far, &normal()));
        assert!(!c.is_vertical_overflow_hidden(&nd, &far, &normal()));
    }

    #[test]
    fn has_border_false_without_and_true_with_a_border_width() {
        let c = CssPropertyCache::empty(1);
        assert!(!c.has_border(&NodeData::create_div(), &n0(), &normal()));

        let bordered = div_with(vec![CssProperty::BorderLeftWidth(CssPropertyValue::Exact(
            LayoutBorderLeftWidth {
                inner: PixelValue::px(2.0),
            },
        ))]);
        assert!(c.has_border(&bordered, &n0(), &normal()));
    }

    #[test]
    fn has_box_shadow_false_for_a_bare_div() {
        let c = CssPropertyCache::empty(1);
        assert!(!c.has_box_shadow(&NodeData::create_div(), &n0(), &normal()));
        // out-of-range node id must not panic either
        assert!(!c.has_box_shadow(&NodeData::create_div(), &NodeId::new(500), &normal()));
    }

    // =====================================================================
    // `*_or_default` getters
    // =====================================================================

    #[test]
    fn or_default_getters_fall_back_to_the_css_defaults() {
        let c = CssPropertyCache::empty(1);
        let nd = NodeData::create_div();

        assert_eq!(
            c.get_font_size_or_default(&nd, &n0(), &normal()),
            azul_css::defaults::DEFAULT_FONT_SIZE
        );
        assert_eq!(
            c.get_text_color_or_default(&nd, &n0(), &normal()),
            azul_css::defaults::DEFAULT_TEXT_COLOR
        );

        let fams = c.get_font_id_or_default(&nd, &n0(), &normal());
        assert_eq!(fams.as_ref().len(), 1);
        match &fams.as_ref()[0] {
            StyleFontFamily::System(s) => {
                assert_eq!(s.as_str(), azul_css::defaults::DEFAULT_FONT_ID);
            }
            other => panic!("expected the default System font family, got {other:?}"),
        }
    }

    #[test]
    fn get_font_size_or_default_prefers_the_inline_value() {
        let c = CssPropertyCache::empty(1);
        let nd = div_with(vec![font_size(PixelValue::px(42.0))]);
        let fs = c.get_font_size_or_default(&nd, &n0(), &normal());
        assert!(close(fs.inner.number.get(), 42.0));
        assert_eq!(fs.inner.metric, SizeMetric::Px);
    }

    #[test]
    fn or_default_getters_survive_an_out_of_range_node_id() {
        let c = CssPropertyCache::empty(0);
        let nd = NodeData::create_div();
        let far = NodeId::new(usize::MAX / 2);
        assert_eq!(
            c.get_font_size_or_default(&nd, &far, &normal()),
            azul_css::defaults::DEFAULT_FONT_SIZE
        );
        assert_eq!(c.get_font_id_or_default(&nd, &far, &normal()).as_ref().len(), 1);
    }

    // =====================================================================
    // calc_* (numeric: zero / negative / NaN / inf / saturation)
    // =====================================================================

    #[test]
    fn calc_width_is_zero_when_unset() {
        let c = CssPropertyCache::empty(1);
        let nd = NodeData::create_div();
        assert_eq!(c.calc_width(&nd, &n0(), &normal(), 800.0), 0.0);
        assert_eq!(c.calc_width(&nd, &n0(), &normal(), 0.0), 0.0);
        assert_eq!(c.calc_height(&nd, &n0(), &normal(), f32::NAN), 0.0);
    }

    #[test]
    fn calc_width_resolves_px_and_percent() {
        let c = CssPropertyCache::empty(1);

        let px = div_with(vec![width_px(100.0)]);
        assert!(close(c.calc_width(&px, &n0(), &normal(), 800.0), 100.0));
        // px must ignore the reference entirely
        assert!(close(c.calc_width(&px, &n0(), &normal(), 0.0), 100.0));

        let pct = div_with(vec![width_pct(50.0)]);
        assert!(close(c.calc_width(&pct, &n0(), &normal(), 800.0), 400.0));
        assert!(close(c.calc_width(&pct, &n0(), &normal(), 0.0), 0.0));
    }

    #[test]
    fn calc_width_with_a_negative_reference_is_negative_not_clamped() {
        let c = CssPropertyCache::empty(1);
        let pct = div_with(vec![width_pct(50.0)]);
        assert!(close(c.calc_width(&pct, &n0(), &normal(), -800.0), -400.0));
    }

    #[test]
    fn calc_width_with_nan_and_infinite_references_is_defined() {
        let c = CssPropertyCache::empty(1);
        let pct = div_with(vec![width_pct(50.0)]);

        assert!(c.calc_width(&pct, &n0(), &normal(), f32::NAN).is_nan());
        assert_eq!(
            c.calc_width(&pct, &n0(), &normal(), f32::INFINITY),
            f32::INFINITY
        );
        assert_eq!(
            c.calc_width(&pct, &n0(), &normal(), f32::NEG_INFINITY),
            f32::NEG_INFINITY
        );
    }

    #[test]
    fn calc_width_saturates_non_finite_pixel_values_at_construction() {
        let c = CssPropertyCache::empty(1);

        // PixelValue stores a fixed-point isize, so `as isize` saturates:
        // NaN => 0, +inf => isize::MAX, -inf => isize::MIN. Nothing panics and
        // nothing leaks a NaN into layout.
        let nan = div_with(vec![width_px(f32::NAN)]);
        assert_eq!(c.calc_width(&nan, &n0(), &normal(), 800.0), 0.0);

        let inf = div_with(vec![width_px(f32::INFINITY)]);
        let got = c.calc_width(&inf, &n0(), &normal(), 800.0);
        assert!(got.is_finite() && got > 0.0, "saturated, got {got}");

        let neg_inf = div_with(vec![width_px(f32::NEG_INFINITY)]);
        let got = c.calc_width(&neg_inf, &n0(), &normal(), 800.0);
        assert!(got.is_finite() && got < 0.0, "saturated, got {got}");

        let huge = div_with(vec![width_px(f32::MAX)]);
        assert!(c.calc_width(&huge, &n0(), &normal(), 800.0).is_finite());
    }

    #[test]
    fn calc_width_of_auto_and_intrinsic_keywords_is_zero() {
        let c = CssPropertyCache::empty(1);

        let auto = div_with(vec![CssProperty::Width(CssPropertyValue::Auto)]);
        assert_eq!(c.calc_width(&auto, &n0(), &normal(), 800.0), 0.0);

        // min-content/max-content are not resolvable here; documented as 0.0.
        let min_content = div_with(vec![CssProperty::Width(CssPropertyValue::Exact(
            LayoutWidth::MinContent,
        ))]);
        assert_eq!(c.calc_width(&min_content, &n0(), &normal(), 800.0), 0.0);
    }

    #[test]
    fn calc_height_mirrors_calc_width() {
        let c = CssPropertyCache::empty(1);
        let nd = div_with(vec![CssProperty::Height(CssPropertyValue::Exact(
            LayoutHeight::Px(PixelValue::percent(25.0)),
        ))]);
        assert!(close(c.calc_height(&nd, &n0(), &normal(), 400.0), 100.0));
        assert!(c.calc_height(&nd, &n0(), &normal(), f32::NAN).is_nan());
    }

    #[test]
    fn calc_min_width_defaults_to_zero_and_max_width_defaults_to_none() {
        let c = CssPropertyCache::empty(1);
        let nd = NodeData::create_div();

        assert_eq!(c.calc_min_width(&nd, &n0(), &normal(), 800.0), 0.0);
        assert_eq!(c.calc_min_height(&nd, &n0(), &normal(), 600.0), 0.0);
        assert_eq!(c.calc_max_width(&nd, &n0(), &normal(), 800.0), None);
        assert_eq!(c.calc_max_height(&nd, &n0(), &normal(), 600.0), None);
    }

    #[test]
    fn calc_min_max_width_resolve_percentages_and_propagate_nan() {
        let c = CssPropertyCache::empty(1);
        let nd = div_with(vec![
            CssProperty::MinWidth(CssPropertyValue::Exact(LayoutMinWidth {
                inner: PixelValue::percent(10.0),
            })),
            CssProperty::MaxWidth(CssPropertyValue::Exact(LayoutMaxWidth {
                inner: PixelValue::percent(90.0),
            })),
        ]);

        assert!(close(c.calc_min_width(&nd, &n0(), &normal(), 1000.0), 100.0));
        assert!(close(
            c.calc_max_width(&nd, &n0(), &normal(), 1000.0).unwrap(),
            900.0
        ));
        assert!(c.calc_min_width(&nd, &n0(), &normal(), f32::NAN).is_nan());
        assert!(c
            .calc_max_width(&nd, &n0(), &normal(), f32::NAN)
            .unwrap()
            .is_nan());
    }

    #[test]
    fn calc_inset_getters_are_none_when_unset_and_some_when_set() {
        let c = CssPropertyCache::empty(1);
        let bare = NodeData::create_div();
        assert_eq!(c.calc_left(&bare, &n0(), &normal(), 800.0), None);
        assert_eq!(c.calc_right(&bare, &n0(), &normal(), 800.0), None);
        assert_eq!(c.calc_top(&bare, &n0(), &normal(), 600.0), None);
        assert_eq!(c.calc_bottom(&bare, &n0(), &normal(), 600.0), None);

        let inset = div_with(vec![
            CssProperty::Left(CssPropertyValue::Exact(LayoutLeft {
                inner: PixelValue::px(5.0),
            })),
            CssProperty::Right(CssPropertyValue::Exact(LayoutRight {
                inner: PixelValue::percent(10.0),
            })),
            CssProperty::Top(CssPropertyValue::Exact(LayoutTop {
                inner: PixelValue::px(-7.0),
            })),
            CssProperty::Bottom(CssPropertyValue::Exact(LayoutInsetBottom {
                inner: PixelValue::px(0.0),
            })),
        ]);
        assert!(close(c.calc_left(&inset, &n0(), &normal(), 800.0).unwrap(), 5.0));
        assert!(close(
            c.calc_right(&inset, &n0(), &normal(), 800.0).unwrap(),
            80.0
        ));
        assert!(close(
            c.calc_top(&inset, &n0(), &normal(), 600.0).unwrap(),
            -7.0
        ));
        assert_eq!(c.calc_bottom(&inset, &n0(), &normal(), 600.0), Some(0.0));
    }

    #[test]
    fn calc_padding_margin_border_default_to_zero() {
        let c = CssPropertyCache::empty(1);
        let nd = NodeData::create_div();
        assert_eq!(c.calc_padding_left(&nd, &n0(), &normal(), 800.0), 0.0);
        assert_eq!(c.calc_padding_right(&nd, &n0(), &normal(), 800.0), 0.0);
        assert_eq!(c.calc_padding_top(&nd, &n0(), &normal(), 600.0), 0.0);
        assert_eq!(c.calc_padding_bottom(&nd, &n0(), &normal(), 600.0), 0.0);
        assert_eq!(c.calc_margin_left(&nd, &n0(), &normal(), 800.0), 0.0);
        assert_eq!(c.calc_margin_right(&nd, &n0(), &normal(), 800.0), 0.0);
        assert_eq!(c.calc_margin_top(&nd, &n0(), &normal(), 600.0), 0.0);
        assert_eq!(c.calc_margin_bottom(&nd, &n0(), &normal(), 600.0), 0.0);
        assert_eq!(c.calc_border_left_width(&nd, &n0(), &normal(), 800.0), 0.0);
        assert_eq!(c.calc_border_right_width(&nd, &n0(), &normal(), 800.0), 0.0);
        assert_eq!(c.calc_border_top_width(&nd, &n0(), &normal(), 600.0), 0.0);
        assert_eq!(c.calc_border_bottom_width(&nd, &n0(), &normal(), 600.0), 0.0);
    }

    #[test]
    fn calc_padding_em_uses_the_default_font_size_not_the_reference() {
        // `calc_*` passes DEFAULT_FONT_SIZE (16px) as both em and rem resolvers,
        // so an em padding must be invariant under the reference width.
        let c = CssPropertyCache::empty(1);
        let nd = div_with(vec![CssProperty::PaddingLeft(CssPropertyValue::Exact(
            LayoutPaddingLeft {
                inner: PixelValue::em(2.0),
            },
        ))]);
        assert!(close(c.calc_padding_left(&nd, &n0(), &normal(), 800.0), 32.0));
        assert!(close(c.calc_padding_left(&nd, &n0(), &normal(), 0.0), 32.0));
        assert!(close(
            c.calc_padding_left(&nd, &n0(), &normal(), f32::NAN),
            32.0
        ));
    }

    #[test]
    fn calc_margin_and_border_resolve_px_and_percent() {
        let c = CssPropertyCache::empty(1);
        let nd = div_with(vec![
            CssProperty::MarginTop(CssPropertyValue::Exact(LayoutMarginTop {
                inner: PixelValue::percent(50.0),
            })),
            CssProperty::BorderLeftWidth(CssPropertyValue::Exact(LayoutBorderLeftWidth {
                inner: PixelValue::px(3.0),
            })),
        ]);
        assert!(close(c.calc_margin_top(&nd, &n0(), &normal(), 200.0), 100.0));
        assert!(close(
            c.calc_border_left_width(&nd, &n0(), &normal(), 800.0),
            3.0
        ));
        assert!(c.calc_margin_top(&nd, &n0(), &normal(), f32::NAN).is_nan());
    }

    #[test]
    fn calc_getters_do_not_panic_on_an_out_of_range_node_id() {
        let c = CssPropertyCache::empty(0);
        let nd = NodeData::create_div();
        let far = NodeId::new(usize::MAX / 2);
        assert_eq!(c.calc_width(&nd, &far, &normal(), 800.0), 0.0);
        assert_eq!(c.calc_max_height(&nd, &far, &normal(), 600.0), None);
        assert_eq!(c.calc_padding_top(&nd, &far, &normal(), f32::INFINITY), 0.0);
    }

    // =====================================================================
    // property_needs_slow_path_after_compact
    // =====================================================================

    #[test]
    fn slow_path_only_needed_for_non_px_pixel_values() {
        // px round-trips through the compact cache => no slow path
        assert!(!property_needs_slow_path_after_compact(&width_px(10.0)));
        // % encodes to SENTINEL => must survive the prune
        assert!(property_needs_slow_path_after_compact(&width_pct(50.0)));

        assert!(!property_needs_slow_path_after_compact(&CssProperty::Height(
            CssPropertyValue::Exact(LayoutHeight::Px(PixelValue::px(1.0)))
        )));
        assert!(property_needs_slow_path_after_compact(&CssProperty::Height(
            CssPropertyValue::Exact(LayoutHeight::Px(PixelValue::em(1.0)))
        )));
    }

    #[test]
    fn slow_path_covers_the_plain_pixelvalue_wrappers() {
        assert!(property_needs_slow_path_after_compact(&font_size(
            PixelValue::rem(2.0)
        )));
        assert!(!property_needs_slow_path_after_compact(&font_size(
            PixelValue::px(16.0)
        )));

        assert!(property_needs_slow_path_after_compact(
            &CssProperty::MinWidth(CssPropertyValue::Exact(LayoutMinWidth {
                inner: PixelValue::percent(10.0),
            }))
        ));
        assert!(!property_needs_slow_path_after_compact(
            &CssProperty::PaddingLeft(CssPropertyValue::Exact(LayoutPaddingLeft {
                inner: PixelValue::px(4.0),
            }))
        ));
    }

    #[test]
    fn slow_path_handles_flex_basis_and_non_pixel_properties() {
        assert!(property_needs_slow_path_after_compact(
            &CssProperty::FlexBasis(CssPropertyValue::Exact(LayoutFlexBasis::Exact(
                PixelValue::percent(50.0)
            )))
        ));
        assert!(!property_needs_slow_path_after_compact(
            &CssProperty::FlexBasis(CssPropertyValue::Exact(LayoutFlexBasis::Auto))
        ));

        // Non-Exact keywords and non-pixel properties never need the slow path.
        assert!(!property_needs_slow_path_after_compact(&CssProperty::Width(
            CssPropertyValue::Auto
        )));
        assert!(!property_needs_slow_path_after_compact(
            &CssProperty::const_none(CssPropertyType::Display)
        ));
        assert!(!property_needs_slow_path_after_compact(
            &CssProperty::const_none(CssPropertyType::BackgroundContent)
        ));
    }

    // =====================================================================
    // clone_inheritable_property (round-trip)
    // =====================================================================

    #[test]
    fn clone_inheritable_property_round_trips_heap_and_pod_variants() {
        // The whole point of this hand-rolled clone is that it must be
        // byte-equivalent to the derived Clone on native.
        let font_family = CssProperty::FontFamily(CssPropertyValue::Exact(
            vec![StyleFontFamily::System(AzString::from_const_str("serif"))].into(),
        ));
        assert_eq!(clone_inheritable_property(&font_family), font_family);

        for p in [
            CssProperty::const_none(CssPropertyType::Cursor),
            CssProperty::const_none(CssPropertyType::TextColor),
            CssProperty::const_none(CssPropertyType::BackgroundContent),
            CssProperty::const_none(CssPropertyType::Transform),
            CssProperty::const_none(CssPropertyType::Content),
            width_px(3.0),
            font_size(PixelValue::em(1.5)),
        ] {
            assert_eq!(clone_inheritable_property(&p), p, "clone must be identity");
            assert_eq!(clone_inheritable_property(&p).get_type(), p.get_type());
        }
    }

    // =====================================================================
    // find_in_stateful / has_state_props / prop_types_for_state
    // =====================================================================

    fn sorted_stateful_fixture() -> Vec<StatefulCssProperty> {
        let mut v = vec![
            stateful(PseudoStateType::Normal, width_px(1.0)),
            stateful(
                PseudoStateType::Normal,
                CssProperty::const_none(CssPropertyType::Display),
            ),
            stateful(PseudoStateType::Hover, width_px(2.0)),
        ];
        // The lookup helpers require (state, prop_type) sort order.
        v.sort_by_key(|p| (p.state, p.prop_type));
        v
    }

    #[test]
    fn find_in_stateful_on_an_empty_slice_is_none() {
        assert!(CssPropertyCache::find_in_stateful(
            &[],
            PseudoStateType::Normal,
            &CssPropertyType::Width
        )
        .is_none());
    }

    #[test]
    fn find_in_stateful_is_keyed_on_both_state_and_prop_type() {
        let v = sorted_stateful_fixture();

        let normal_width =
            CssPropertyCache::find_in_stateful(&v, PseudoStateType::Normal, &CssPropertyType::Width)
                .expect("normal width present");
        assert_eq!(normal_width.get_type(), CssPropertyType::Width);

        let hover_width =
            CssPropertyCache::find_in_stateful(&v, PseudoStateType::Hover, &CssPropertyType::Width)
                .expect("hover width present");
        // same prop type, different state => a different entry
        assert_ne!(normal_width, hover_width);

        // present prop type, absent state
        assert!(CssPropertyCache::find_in_stateful(
            &v,
            PseudoStateType::Focus,
            &CssPropertyType::Width
        )
        .is_none());
        // present state, absent prop type
        assert!(CssPropertyCache::find_in_stateful(
            &v,
            PseudoStateType::Hover,
            &CssPropertyType::Display
        )
        .is_none());
    }

    #[test]
    fn has_state_props_true_false_and_edges() {
        let v = sorted_stateful_fixture();
        assert!(CssPropertyCache::has_state_props(&v, PseudoStateType::Normal));
        assert!(CssPropertyCache::has_state_props(&v, PseudoStateType::Hover));
        assert!(!CssPropertyCache::has_state_props(&v, PseudoStateType::Focus));
        // empty slice: deterministic false, no partition_point OOB read
        assert!(!CssPropertyCache::has_state_props(
            &[],
            PseudoStateType::Normal
        ));
    }

    #[test]
    fn prop_types_for_state_filters_by_state() {
        let v = sorted_stateful_fixture();

        let mut normal: Vec<CssPropertyType> =
            CssPropertyCache::prop_types_for_state(&v, PseudoStateType::Normal)
                .copied()
                .collect();
        normal.sort_unstable();
        assert_eq!(normal.len(), 2);
        assert!(normal.contains(&CssPropertyType::Width));
        assert!(normal.contains(&CssPropertyType::Display));

        let hover: Vec<CssPropertyType> =
            CssPropertyCache::prop_types_for_state(&v, PseudoStateType::Hover)
                .copied()
                .collect();
        assert_eq!(hover, vec![CssPropertyType::Width]);

        assert_eq!(
            CssPropertyCache::prop_types_for_state(&v, PseudoStateType::Active).count(),
            0
        );
        assert_eq!(
            CssPropertyCache::prop_types_for_state(&[], PseudoStateType::Normal).count(),
            0
        );
    }

    // =====================================================================
    // font-size resolution (numeric)
    // =====================================================================

    #[test]
    fn resolve_font_size_to_pixels_converts_absolute_units() {
        let px = CssPropertyCache::resolve_font_size_to_pixels(&font_size(PixelValue::px(20.0)), 10.0);
        let (metric, n) = font_size_parts(&px).unwrap();
        assert_eq!(metric, SizeMetric::Px);
        assert!(close(n, 20.0));

        let pt = CssPropertyCache::resolve_font_size_to_pixels(&font_size(PixelValue::pt(12.0)), 10.0);
        assert!(close(font_size_parts(&pt).unwrap().1, 12.0 * PT_TO_PX));
    }

    #[test]
    fn resolve_font_size_to_pixels_em_scales_by_reference_but_rem_does_not() {
        let em =
            CssPropertyCache::resolve_font_size_to_pixels(&font_size(PixelValue::em(2.0)), 10.0);
        assert!(close(font_size_parts(&em).unwrap().1, 20.0));

        // rem deliberately ignores the reference and uses DEFAULT_FONT_SIZE (16).
        let rem =
            CssPropertyCache::resolve_font_size_to_pixels(&font_size(PixelValue::rem(2.0)), 10.0);
        assert!(close(font_size_parts(&rem).unwrap().1, 32.0));

        let pct = CssPropertyCache::resolve_font_size_to_pixels(
            &font_size(PixelValue::percent(50.0)),
            10.0,
        );
        assert!(close(font_size_parts(&pct).unwrap().1, 5.0));
    }

    #[test]
    fn resolve_font_size_to_pixels_with_nan_and_infinite_references() {
        // NaN * anything => NaN => saturates to 0 in the fixed-point encoding.
        let nan =
            CssPropertyCache::resolve_font_size_to_pixels(&font_size(PixelValue::em(2.0)), f32::NAN);
        let (metric, n) = font_size_parts(&nan).unwrap();
        assert_eq!(metric, SizeMetric::Px);
        assert_eq!(n, 0.0, "NaN must not escape into the cascade");

        let inf = CssPropertyCache::resolve_font_size_to_pixels(
            &font_size(PixelValue::em(2.0)),
            f32::INFINITY,
        );
        let n = font_size_parts(&inf).unwrap().1;
        assert!(n.is_finite() && n > 0.0, "saturated, got {n}");

        let zero =
            CssPropertyCache::resolve_font_size_to_pixels(&font_size(PixelValue::em(2.0)), 0.0);
        assert_eq!(font_size_parts(&zero).unwrap().1, 0.0);

        let neg =
            CssPropertyCache::resolve_font_size_to_pixels(&font_size(PixelValue::em(2.0)), -10.0);
        assert!(close(font_size_parts(&neg).unwrap().1, -20.0));
    }

    #[test]
    fn resolve_font_size_to_pixels_passes_through_unresolvable_inputs() {
        // viewport units need a viewport => returned unchanged
        let vw = font_size(PixelValue::from_metric(SizeMetric::Vw, 10.0));
        assert_eq!(CssPropertyCache::resolve_font_size_to_pixels(&vw, 16.0), vw);

        // a non-font-size property is returned verbatim
        let w = width_px(10.0);
        assert_eq!(CssPropertyCache::resolve_font_size_to_pixels(&w, 16.0), w);

        // a keyword (non-Exact) font-size has no PixelValue to convert
        let inherit = CssProperty::FontSize(CssPropertyValue::Inherit);
        assert_eq!(
            CssPropertyCache::resolve_font_size_to_pixels(&inherit, 16.0),
            inherit
        );
    }

    #[test]
    fn has_relative_font_size_unit_true_false_and_edges() {
        assert!(CssPropertyCache::has_relative_font_size_unit(&font_size(
            PixelValue::em(1.0)
        )));
        assert!(CssPropertyCache::has_relative_font_size_unit(&font_size(
            PixelValue::rem(1.0)
        )));
        assert!(CssPropertyCache::has_relative_font_size_unit(&font_size(
            PixelValue::percent(100.0)
        )));

        assert!(!CssPropertyCache::has_relative_font_size_unit(&font_size(
            PixelValue::px(16.0)
        )));
        assert!(!CssPropertyCache::has_relative_font_size_unit(&font_size(
            PixelValue::pt(12.0)
        )));
        // keyword font-size and non-font-size properties are not "relative"
        assert!(!CssPropertyCache::has_relative_font_size_unit(
            &CssProperty::FontSize(CssPropertyValue::Auto)
        ));
        assert!(!CssPropertyCache::has_relative_font_size_unit(&width_px(1.0)));
    }

    // =====================================================================
    // resolve_property_dependency
    // =====================================================================

    #[test]
    fn resolve_property_dependency_scales_relative_targets_by_an_absolute_reference() {
        let reference = font_size(PixelValue::px(10.0));

        let em = CssPropertyCache::resolve_property_dependency(
            &font_size(PixelValue::em(2.0)),
            &reference,
        )
        .expect("em resolves against an absolute reference");
        assert!(close(font_size_parts(&em).unwrap().1, 20.0));

        let pct = CssPropertyCache::resolve_property_dependency(
            &font_size(PixelValue::percent(50.0)),
            &reference,
        )
        .expect("percent resolves");
        assert!(close(font_size_parts(&pct).unwrap().1, 5.0));

        // The reference itself may be in any absolute unit.
        let pt_ref = font_size(PixelValue::pt(10.0));
        let em2 =
            CssPropertyCache::resolve_property_dependency(&font_size(PixelValue::em(2.0)), &pt_ref)
                .expect("pt reference is absolute");
        assert!(close(
            font_size_parts(&em2).unwrap().1,
            2.0 * 10.0 * PT_TO_PX
        ));
    }

    #[test]
    fn resolve_property_dependency_rewrites_the_target_variant_in_place() {
        let reference = font_size(PixelValue::px(10.0));
        let padding = CssProperty::PaddingLeft(CssPropertyValue::Exact(LayoutPaddingLeft {
            inner: PixelValue::em(3.0),
        }));
        let out = CssPropertyCache::resolve_property_dependency(&padding, &reference)
            .expect("padding is a supported target");
        match out {
            CssProperty::PaddingLeft(v) => {
                let inner = v.get_property().unwrap().inner;
                assert_eq!(inner.metric, SizeMetric::Px);
                assert!(close(inner.number.get(), 30.0));
            }
            other => panic!("variant must be preserved, got {other:?}"),
        }
    }

    #[test]
    fn resolve_property_dependency_returns_none_for_unresolvable_inputs() {
        let abs = font_size(PixelValue::px(10.0));

        // a relative reference cannot anchor anything
        assert!(CssPropertyCache::resolve_property_dependency(
            &font_size(PixelValue::em(2.0)),
            &font_size(PixelValue::em(2.0))
        )
        .is_none());
        // viewport-unit target needs a viewport
        assert!(CssPropertyCache::resolve_property_dependency(
            &font_size(PixelValue::from_metric(SizeMetric::Vh, 5.0)),
            &abs
        )
        .is_none());
        // unsupported target type (no PixelValue to extract)
        assert!(CssPropertyCache::resolve_property_dependency(&width_px(5.0), &abs).is_none());
        // unsupported reference type
        assert!(CssPropertyCache::resolve_property_dependency(
            &font_size(PixelValue::em(2.0)),
            &width_px(5.0)
        )
        .is_none());
        // keyword (non-Exact) target
        assert!(CssPropertyCache::resolve_property_dependency(
            &CssProperty::FontSize(CssPropertyValue::Inherit),
            &abs
        )
        .is_none());
    }

    // =====================================================================
    // should_apply_cascaded
    // =====================================================================

    #[test]
    fn should_apply_cascaded_respects_origin_and_relative_font_sizes() {
        let own = |p: CssProperty| {
            vec![(
                p.get_type(),
                CssPropertyWithOrigin {
                    property: p,
                    origin: CssPropertyOrigin::Own,
                },
            )]
        };
        let inherited = |p: CssProperty| {
            vec![(
                p.get_type(),
                CssPropertyWithOrigin {
                    property: p,
                    origin: CssPropertyOrigin::Inherited,
                },
            )]
        };

        // nothing computed yet => apply
        assert!(CssPropertyCache::should_apply_cascaded(
            &[],
            CssPropertyType::Width,
            &width_px(1.0)
        ));

        // the node already set it itself => the UA/cascaded value must not win
        assert!(!CssPropertyCache::should_apply_cascaded(
            &own(width_px(2.0)),
            CssPropertyType::Width,
            &width_px(1.0)
        ));

        // an inherited value is weaker than a cascaded one => apply
        assert!(CssPropertyCache::should_apply_cascaded(
            &inherited(width_px(2.0)),
            CssPropertyType::Width,
            &width_px(1.0)
        ));

        // A cascaded (UA/author) font-size — relative OR absolute — overrides an
        // inherited value: it is the node's own declared size (e.g. <h1>'s UA
        // `font-size: 2em`), and `resolve_font_size_property` resolves the `em`
        // against the parent's size, so there is no double-scaling.
        let inherited_fs = inherited(font_size(PixelValue::px(20.0)));
        assert!(CssPropertyCache::should_apply_cascaded(
            &inherited_fs,
            CssPropertyType::FontSize,
            &font_size(PixelValue::em(2.0))
        ));
        assert!(CssPropertyCache::should_apply_cascaded(
            &inherited_fs,
            CssPropertyType::FontSize,
            &font_size(PixelValue::px(12.0))
        ));
    }

    // =====================================================================
    // get_property / get_property_slow (cascade layering)
    // =====================================================================

    #[test]
    fn get_property_finds_an_inline_normal_property() {
        let c = CssPropertyCache::empty(1);
        let nd = div_with(vec![width_px(100.0)]);
        let got = c
            .get_property(&nd, &n0(), &normal(), &CssPropertyType::Width)
            .expect("inline width");
        assert_eq!(*got, width_px(100.0));
    }

    #[test]
    fn get_property_ignores_pseudo_state_props_unless_the_state_is_active() {
        let c = CssPropertyCache::empty(1);
        let nd = div_with_pseudo(vec![width_px(100.0)], PseudoStateType::Hover);

        assert!(
            c.get_property(&nd, &n0(), &normal(), &CssPropertyType::Width)
                .is_none(),
            ":hover width must not leak into the Normal state"
        );

        let hovered = StyledNodeState {
            hover: true,
            ..StyledNodeState::default()
        };
        assert_eq!(
            c.get_property(&nd, &n0(), &hovered, &CssPropertyType::Width),
            Some(&width_px(100.0))
        );
    }

    #[test]
    fn get_property_user_override_beats_inline_and_stylesheet() {
        let mut c = CssPropertyCache::empty(1);
        c.user_overridden_properties
            .push(vec![(CssPropertyType::Width, width_px(1.0))]);
        c.css_props
            .push_to(0, stateful(PseudoStateType::Normal, width_px(2.0)));
        c.css_props.sort_each_and_flatten(|p| (p.state, p.prop_type));

        let nd = div_with(vec![width_px(3.0)]);
        assert_eq!(
            c.get_property(&nd, &n0(), &normal(), &CssPropertyType::Width),
            Some(&width_px(1.0)),
            "user override is the top cascade layer"
        );
    }

    #[test]
    fn get_property_falls_back_through_stylesheet_global_cascaded_then_ua() {
        let nd = NodeData::create_div();

        // stylesheet layer
        let mut c = CssPropertyCache::empty(1);
        c.css_props
            .push_to(0, stateful(PseudoStateType::Normal, width_px(2.0)));
        c.css_props.sort_each_and_flatten(|p| (p.state, p.prop_type));
        assert_eq!(
            c.get_property(&nd, &n0(), &normal(), &CssPropertyType::Width),
            Some(&width_px(2.0))
        );

        // `*` global layer (below per-node rules)
        let mut c = CssPropertyCache::empty(1);
        c.global_css_props.push(width_px(4.0));
        assert_eq!(
            c.get_property(&nd, &n0(), &normal(), &CssPropertyType::Width),
            Some(&width_px(4.0))
        );

        // cascaded (inherited/UA) layer
        let mut c = CssPropertyCache::empty(1);
        c.cascaded_props
            .push_to(0, stateful(PseudoStateType::Normal, width_px(5.0)));
        c.cascaded_props
            .sort_each_and_flatten(|p| (p.state, p.prop_type));
        assert_eq!(
            c.get_property(&nd, &n0(), &normal(), &CssPropertyType::Width),
            Some(&width_px(5.0))
        );

        // UA fallback: a <div> has no UA width, but it does have `display: block`
        let c = CssPropertyCache::empty(1);
        assert!(c
            .get_property(&nd, &n0(), &normal(), &CssPropertyType::Width)
            .is_none());
        assert!(c
            .get_property(&nd, &n0(), &normal(), &CssPropertyType::Display)
            .is_some());
    }

    #[test]
    fn get_property_on_an_out_of_range_node_id_falls_through_to_ua_css() {
        let c = CssPropertyCache::empty(0);
        let nd = NodeData::create_div();
        let far = NodeId::new(usize::MAX / 2);

        assert!(c
            .get_property(&nd, &far, &normal(), &CssPropertyType::Width)
            .is_none());
        assert!(
            c.get_property(&nd, &far, &normal(), &CssPropertyType::Display)
                .is_some(),
            "UA CSS is node-type-keyed, not index-keyed"
        );
    }

    #[test]
    fn get_property_with_context_matches_pseudo_state_conditions() {
        let c = CssPropertyCache::empty(1);
        let nd = div_with_pseudo(vec![width_px(100.0)], PseudoStateType::Hover);

        let plain = DynamicSelectorContext::default();
        assert!(c
            .get_property_with_context(&nd, &n0(), &plain, &CssPropertyType::Width)
            .is_none());

        let mut hovered = DynamicSelectorContext::default();
        hovered.pseudo_state.hover = true;
        assert_eq!(
            c.get_property_with_context(&nd, &n0(), &hovered, &CssPropertyType::Width),
            Some(&width_px(100.0))
        );
    }

    #[test]
    fn check_properties_changed_only_fires_when_a_condition_flips() {
        let plain = DynamicSelectorContext::default();
        let mut hovered = DynamicSelectorContext::default();
        hovered.pseudo_state.hover = true;

        // unconditional props never "change" between contexts
        let unconditional = div_with(vec![width_px(1.0)]);
        assert!(!CssPropertyCache::check_properties_changed(
            &unconditional,
            &plain,
            &hovered
        ));

        let conditional = div_with_pseudo(vec![width_px(1.0)], PseudoStateType::Hover);
        assert!(CssPropertyCache::check_properties_changed(
            &conditional,
            &plain,
            &hovered
        ));
        assert!(
            !CssPropertyCache::check_properties_changed(&conditional, &plain, &plain),
            "identical contexts can never differ"
        );

        // a node with no inline style at all
        assert!(!CssPropertyCache::check_properties_changed(
            &NodeData::create_div(),
            &plain,
            &hovered
        ));
    }

    #[test]
    fn check_layout_properties_changed_ignores_non_layout_properties() {
        let plain = DynamicSelectorContext::default();
        let mut hovered = DynamicSelectorContext::default();
        hovered.pseudo_state.hover = true;

        let layout = div_with_pseudo(vec![width_px(1.0)], PseudoStateType::Hover);
        assert!(CssPropertyCache::check_layout_properties_changed(
            &layout, &plain, &hovered
        ));
        assert!(CssPropertyType::Width.can_trigger_relayout());

        // A paint-only property flipping must not force a relayout.
        let paint = div_with_pseudo(
            vec![CssProperty::const_none(CssPropertyType::BackgroundContent)],
            PseudoStateType::Hover,
        );
        assert!(!CssPropertyType::BackgroundContent.can_trigger_relayout());
        assert!(!CssPropertyCache::check_layout_properties_changed(
            &paint, &plain, &hovered
        ));
        // ...though the generic check still sees it
        assert!(CssPropertyCache::check_properties_changed(
            &paint, &plain, &hovered
        ));
    }

    // =====================================================================
    // grid-gap / scrollbar getters
    // =====================================================================

    #[test]
    fn grid_gap_and_scrollbar_getters_are_none_on_a_bare_div() {
        let c = CssPropertyCache::empty(1);
        let nd = NodeData::create_div();
        assert!(c.get_grid_gap(&nd, &n0(), &normal()).is_none());
        assert!(c.get_scrollbar_track(&nd, &n0(), &normal()).is_none());
        assert!(c.get_scrollbar_thumb(&nd, &n0(), &normal()).is_none());
        assert!(c.get_scrollbar_button(&nd, &n0(), &normal()).is_none());
        assert!(c.get_scrollbar_corner(&nd, &n0(), &normal()).is_none());
        assert!(c.get_scrollbar_resizer(&nd, &n0(), &normal()).is_none());

        // and on an out-of-range node id
        let far = NodeId::new(4_242);
        assert!(c.get_grid_gap(&nd, &far, &normal()).is_none());
        assert!(c.get_scrollbar_thumb(&nd, &far, &normal()).is_none());
    }

    // =====================================================================
    // get_computed_css_style_string
    // =====================================================================

    #[test]
    fn computed_css_style_string_serializes_set_properties() {
        let c = CssPropertyCache::empty(1);

        // A bare <div> still gets `display: block` from the UA sheet.
        let s = c.get_computed_css_style_string(&NodeData::create_div(), &n0(), &normal());
        assert!(s.contains("display:"), "got {s:?}");

        let styled = div_with(vec![width_px(100.0), font_size(PixelValue::px(12.0))]);
        let s = c.get_computed_css_style_string(&styled, &n0(), &normal());
        assert!(s.contains("width:"), "got {s:?}");
        assert!(s.contains("font-size:"), "got {s:?}");
        assert!(s.ends_with(';'), "each declaration is terminated: {s:?}");
    }

    #[test]
    fn computed_css_style_string_does_not_panic_on_an_out_of_range_node_id() {
        let c = CssPropertyCache::empty(0);
        let s = c.get_computed_css_style_string(
            &NodeData::create_div(),
            &NodeId::new(usize::MAX / 2),
            &normal(),
        );
        assert!(s.contains("display:"));
    }

    // =====================================================================
    // apply_ua_css / sort_cascaded_props / prune_compact_normal_props
    // =====================================================================

    #[test]
    fn apply_ua_css_inserts_ua_properties_into_cascaded_props() {
        let nodes = vec![NodeData::create_div()];
        let mut c = CssPropertyCache::empty(1);
        c.apply_ua_css(&nodes);

        let props = c.cascaded_props.build_get(0).expect("build phase");
        assert!(
            props
                .iter()
                .any(|p| p.prop_type == CssPropertyType::Display
                    && p.state == PseudoStateType::Normal),
            "UA `div {{ display: block }}` must land in the cascade"
        );
    }

    #[test]
    fn apply_ua_css_does_not_override_an_existing_inline_property() {
        let nodes = vec![div_with(vec![CssProperty::const_none(
            CssPropertyType::Display,
        )])];
        let mut c = CssPropertyCache::empty(1);
        c.apply_ua_css(&nodes);

        let props = c.cascaded_props.build_get(0).expect("build phase");
        assert!(
            !props.iter().any(|p| p.prop_type == CssPropertyType::Display),
            "UA CSS is the weakest layer and must not clobber inline"
        );
    }

    #[test]
    fn apply_ua_css_on_zero_nodes_returns_early() {
        let mut c = CssPropertyCache::empty(0);
        c.apply_ua_css(&[]);
        assert_eq!(c.cascaded_props.len(), 0);
    }

    #[test]
    fn sort_cascaded_props_flattens_and_orders_by_state_then_type() {
        let mut c = CssPropertyCache::empty(1);
        c.cascaded_props
            .push_to(0, stateful(PseudoStateType::Hover, width_px(1.0)));
        c.cascaded_props.push_to(
            0,
            stateful(
                PseudoStateType::Normal,
                CssProperty::const_none(CssPropertyType::Display),
            ),
        );
        c.cascaded_props
            .push_to(0, stateful(PseudoStateType::Normal, width_px(2.0)));

        c.sort_cascaded_props();

        assert!(c.cascaded_props.is_flattened());
        let slice = c.cascaded_props.get_slice(0);
        assert_eq!(slice.len(), 3);
        let keys: Vec<_> = slice.iter().map(|p| (p.state, p.prop_type)).collect();
        let mut sorted = keys.clone();
        sorted.sort_unstable();
        assert_eq!(keys, sorted, "binary_search lookups require sort order");
    }

    #[test]
    fn prune_compact_normal_props_keeps_what_the_slow_path_still_needs() {
        let mut c = CssPropertyCache::empty(1);
        // Normal + compact-encoded + fully representable => droppable
        c.cascaded_props.push_to(
            0,
            stateful(
                PseudoStateType::Normal,
                CssProperty::const_none(CssPropertyType::Display),
            ),
        );
        // Normal + compact-encoded but SENTINEL-encoded (%) => must survive
        c.cascaded_props
            .push_to(0, stateful(PseudoStateType::Normal, width_pct(50.0)));
        // Normal + no compact encoding at all => must survive
        c.cascaded_props.push_to(
            0,
            stateful(
                PseudoStateType::Normal,
                CssProperty::const_none(CssPropertyType::BackgroundContent),
            ),
        );
        // non-Normal => always survives
        c.cascaded_props.push_to(
            0,
            stateful(
                PseudoStateType::Hover,
                CssProperty::const_none(CssPropertyType::Display),
            ),
        );

        c.prune_compact_normal_props();

        let kept: Vec<(PseudoStateType, CssPropertyType)> = c
            .cascaded_props
            .get_slice(0)
            .iter()
            .map(|p| (p.state, p.prop_type))
            .collect();

        assert!(
            !kept.contains(&(PseudoStateType::Normal, CssPropertyType::Display)),
            "the compact cache is authoritative for this one"
        );
        assert!(kept.contains(&(PseudoStateType::Normal, CssPropertyType::Width)));
        assert!(kept.contains(&(PseudoStateType::Normal, CssPropertyType::BackgroundContent)));
        assert!(kept.contains(&(PseudoStateType::Hover, CssPropertyType::Display)));
        assert_eq!(kept.len(), 3);
    }

    #[test]
    fn prune_compact_normal_props_on_an_empty_cache_does_not_panic() {
        let mut c = CssPropertyCache::empty(0);
        c.prune_compact_normal_props();
        assert_eq!(c.cascaded_props.len(), 0);

        let mut c = CssPropertyCache::empty(3);
        c.prune_compact_normal_props();
        assert_eq!(c.cascaded_props.len(), 3);
        assert!(c.cascaded_props.get_slice(0).is_empty());
    }

    // =====================================================================
    // compute_inherited_values
    // =====================================================================

    /// `[root, child]`, child's parent = root (the hierarchy uses 1-based ids).
    fn two_node_hierarchy() -> Vec<NodeHierarchyItem> {
        vec![
            NodeHierarchyItem {
                parent: 0,
                previous_sibling: 0,
                next_sibling: 0,
                last_child: 2,
            },
            NodeHierarchyItem {
                parent: 1,
                previous_sibling: 0,
                next_sibling: 0,
                last_child: 0,
            },
        ]
    }

    #[test]
    fn compute_inherited_values_propagates_font_size_to_children() {
        let hierarchy = two_node_hierarchy();
        assert_eq!(hierarchy[1].parent_id(), Some(NodeId::new(0)));

        let nodes = vec![
            div_with(vec![font_size(PixelValue::px(20.0))]),
            NodeData::create_div(),
        ];
        let mut c = CssPropertyCache::empty(2);
        let changed = c.compute_inherited_values(&hierarchy, &nodes);

        assert_eq!(c.computed_values.len(), 2);
        assert_eq!(changed.len(), 2, "both nodes gained a computed value");

        let (t, v) = &c.computed_values[1][0];
        assert_eq!(*t, CssPropertyType::FontSize);
        assert_eq!(v.origin, CssPropertyOrigin::Inherited);
        assert!(close(font_size_parts(&v.property).unwrap().1, 20.0));

        // the parent's own value keeps the Own origin
        assert_eq!(c.computed_values[0][0].1.origin, CssPropertyOrigin::Own);
    }

    #[test]
    fn compute_inherited_values_resolves_a_child_em_against_the_parent_px() {
        let hierarchy = two_node_hierarchy();
        let nodes = vec![
            div_with(vec![font_size(PixelValue::px(20.0))]),
            div_with(vec![font_size(PixelValue::em(2.0))]),
        ];
        let mut c = CssPropertyCache::empty(2);
        c.compute_inherited_values(&hierarchy, &nodes);

        let (t, v) = &c.computed_values[1][0];
        assert_eq!(*t, CssPropertyType::FontSize);
        assert_eq!(v.origin, CssPropertyOrigin::Own);
        let (metric, n) = font_size_parts(&v.property).unwrap();
        assert_eq!(metric, SizeMetric::Px, "resolved to absolute px");
        assert!(close(n, 40.0), "2em of the parent's 20px, got {n}");
    }

    #[test]
    fn compute_inherited_values_is_idempotent_on_a_second_run() {
        let hierarchy = two_node_hierarchy();
        let nodes = vec![
            div_with(vec![font_size(PixelValue::px(20.0))]),
            NodeData::create_div(),
        ];
        let mut c = CssPropertyCache::empty(2);
        assert_eq!(c.compute_inherited_values(&hierarchy, &nodes).len(), 2);
        assert!(
            c.compute_inherited_values(&hierarchy, &nodes).is_empty(),
            "nothing changed the second time around"
        );
    }

    #[test]
    fn compute_inherited_values_on_an_empty_tree_does_not_panic() {
        let mut c = CssPropertyCache::empty(0);
        assert!(c.compute_inherited_values(&[], &[]).is_empty());
        assert!(c.computed_values.is_empty());
    }

    // =====================================================================
    // restyle / generate_tag_ids
    // =====================================================================

    fn one_node_scaffold() -> (NodeHierarchyItemVec, NodeDataContainer<CascadeInfo>) {
        (
            vec![NodeHierarchyItem::zeroed()].into(),
            NodeDataContainer::new(vec![CascadeInfo {
                index_in_parent: 0,
                is_last_child: true,
            }]),
        )
    }

    #[test]
    fn restyle_with_an_empty_stylesheet_flattens_and_yields_no_tags() {
        let (hierarchy, cascade) = one_node_scaffold();
        let nodes = NodeDataContainer::new(vec![NodeData::create_div()]);
        let non_leaf: ParentWithNodeDepthVec = Vec::new().into();
        let mut css = Css::empty();

        let mut c = CssPropertyCache::empty(1);
        let tags = c.restyle(
            &mut css,
            &nodes.as_ref(),
            &hierarchy,
            &non_leaf,
            &cascade.as_ref(),
        );

        assert!(tags.is_empty(), "a plain div needs no hit-test tag");
        assert!(
            c.css_props.is_flattened(),
            "restyle must leave css_props in read phase"
        );
        assert!(c.resolved_font_sizes_px.get().is_none());
    }

    #[test]
    fn generate_tag_ids_skips_inert_nodes_and_tags_interactive_ones() {
        let (hierarchy, _) = one_node_scaffold();

        let inert = NodeDataContainer::new(vec![NodeData::create_div()]);
        let c = CssPropertyCache::empty(1);
        assert!(c.generate_tag_ids(&inert.as_ref(), &hierarchy).is_empty());

        // an inline :hover rule makes the node hit-testable
        let hoverable = NodeDataContainer::new(vec![div_with_pseudo(
            vec![width_px(1.0)],
            PseudoStateType::Hover,
        )]);
        let tags = c.generate_tag_ids(&hoverable.as_ref(), &hierarchy);
        assert_eq!(tags.len(), 1);
        assert_eq!(
            tags[0].node_id.into_crate_internal(),
            Some(NodeId::new(0))
        );
    }

    #[test]
    fn generate_tag_ids_tags_a_node_with_a_cursor_declaration() {
        let (hierarchy, _) = one_node_scaffold();
        let nodes = NodeDataContainer::new(vec![div_with(vec![CssProperty::const_none(
            CssPropertyType::Cursor,
        )])]);
        let c = CssPropertyCache::empty(1);
        assert_eq!(c.generate_tag_ids(&nodes.as_ref(), &hierarchy).len(), 1);
    }

    #[test]
    fn generate_tag_ids_on_an_empty_dom_yields_nothing() {
        let nodes: NodeDataContainer<NodeData> = NodeDataContainer::new(Vec::new());
        let hierarchy: NodeHierarchyItemVec = Vec::new().into();
        let c = CssPropertyCache::empty(0);
        assert!(c.generate_tag_ids(&nodes.as_ref(), &hierarchy).is_empty());
    }

    // =====================================================================
    // std-gated profiling helpers
    // =====================================================================

    #[cfg(feature = "std")]
    #[test]
    fn css_prop_type_label_is_interned_and_distinct_per_variant() {
        let a = CssPropertyCache::css_prop_type_label(&CssPropertyType::Width);
        let b = CssPropertyCache::css_prop_type_label(&CssPropertyType::Width);
        assert!(!a.is_empty());
        assert_eq!(
            a.as_ptr(),
            b.as_ptr(),
            "the label table must leak at most one &'static str per variant"
        );

        let other = CssPropertyCache::css_prop_type_label(&CssPropertyType::Height);
        assert_ne!(a, other);
    }

    #[cfg(feature = "std")]
    #[test]
    fn drain_css_prop_counts_is_sorted_descending_and_drains() {
        // The counter is thread-local and only records when AZ_PROP_COUNT=1, so
        // the contract to pin here is "never panics, and drains".
        let first = drain_css_prop_counts();
        for w in first.windows(2) {
            assert!(w[0].1 >= w[1].1, "counts must be sorted descending");
        }
        assert!(
            drain_css_prop_counts().is_empty(),
            "a drained counter comes back empty"
        );
    }
}