CSSForge

CSSForge is a safety-first, lossless semantic CSS refactoring engine and interactive terminal workbench written in Rust. It modernizes flat legacy CSS into native nesting, Range media queries, :is() factoring, and @layer consolidation with zero declaration loss and byte-range surgical precision.

📖 Full Interactive Documentation & Rules Catalog: https://jayeshmepani.github.io/cssforge/ (or open docs/index.html locally).

📦 Published Workspace Crates

Package	Type	Crates.io	Description
cssforge	CLI / TUI Binary		Standalone executable with both an interactive visual terminal UI (TUI workbench) and headless CLI.
cssforge-core	Pure Rust Library		Headless AST parser, specificity calculator, and 26 transformation rules with zero UI dependencies.
cssforge-tui	UI Component		Reusable Ratatui/Crossterm interface, ASCII banner, step-by-step wizard, and unified diff viewer.

🚀 Installation

Option 1: Via Cargo (All Platforms — Recommended)

cargo install cssforge

Option 2: Pre-compiled Standalone Binaries

Download from GitHub Releases:

🐧 Linux (x64 / ARM64)

# Extract and copy to local user bin (no sudo needed):
tar -xzf cssforge-v0.3.1-linux-x64.tar.gz
cp cssforge-v0.3.1-linux-x64/cssforge ~/.local/bin/
chmod +x ~/.local/bin/cssforge

🍏 macOS (Apple Silicon M-Series)

tar -xzf cssforge-v0.3.1-macos-arm64.tar.gz
cp cssforge-v0.3.1-macos-arm64/cssforge ~/.local/bin/
chmod +x ~/.local/bin/cssforge

🪟 Windows (x64 / ARM64 Snapdragon)

Extract cssforge.exe from cssforge-v0.3.1-windows-x64.zip and move it to any directory in your system Path (e.g. C:\Windows\System32 or your tools folder).

📁 Smart File Discovery & Default Ignored Conventions

When executing cssforge without arguments in any project directory (.), CSSForge automatically scans for human-authored .css files while applying zero-config safe discovery rules:

🚫 Automatically Ignored Directories & Purposes

• node_modules/, vendor/ — Third-party dependencies that should never be mutated by local refactoring tools.
• target/, dist/, build/, out/, .next/, .nuxt/, .turbo/, .svelte-kit/ — Ephemeral build and bundler output artifacts.
• .git/, .hg/, .svn/, .cache/ — Version control internals and compiler caches.

🚫 Automatically Ignored File Patterns & Purposes

• *.modern.css — Generated CSSForge output files (prevents infinite recursion loops).
• *.min.css, *.bundle.css, *.chunk.css — Minified/bundled CSS where identifiers and structures are intentionally mangled and not meant for source AST nesting.
• *.bak.css, *.backup.css — Safety backup files created prior to in-place overwrites.
• *.map.css — Source map artifacts.

Tip (Explicit Target Override): If you explicitly specify a file path (e.g. cssforge interactive ./dist/bundle.min.css), CSSForge will directly process the requested file. Standard .gitignore rules are also natively respected.

💡 Usage in Any Project

CSSForge automatically scans for CSS files in the current working directory or any path you pass:

1. Interactive TUI Workbench

# Go to ANY web project folder:
cd /path/to/my-project

# Launch interactive modernization:
cssforge

# Or target a specific folder / file:
cssforge interactive ./src/css

Keyboard Shortcuts

• [Enter] Next step / Apply
• [Space] Toggle file or rule selection
• [a] Select / Deselect All
• [p] Cycle presets (Conservative ➔ Modern ➔ Refactor ➔ Aggressive)
• [d] / [v] Open live unified code diff & safety proof checklist
• [q] Quit

2. Headless CLI (CI/CD & Automation)

# Analyze CSS files and report modernization findings
cssforge analyze ./src

# Analyze with structured JSON output
cssforge analyze ./src --json

# Apply modern preset to new files (*.modern.css)
cssforge apply ./src/app.css --preset modern --output new-file

# Overwrite in-place with automatic safety backup (.bak)
cssforge apply ./src/app.css --output overwrite-with-backup --yes

# List all 26 transformation rules
cssforge rules

🛠️ 26 Transformation Rules Summary

• Native Nesting: nest-pseudo-class, nest-pseudo-element, nest-attribute, nest-compound, nest-descendant, nest-combinator, factor-selector-list.
• Conditional At-Rules: nest-media, nest-supports, nest-container, nest-starting-style.
• Modern Selectors: consolidate-not, modernize-is, modernize-where, modernize-media-range-syntax.
• At-Rule Merging: merge-same-named-layer, merge-adjacent-media, merge-adjacent-supports, merge-adjacent-container, merge-identical-scope, merge-identical-starting-style.
• Deduplication & Pruning: merge-adjacent-identical-selector, merge-identical-rule-bodies, factor-identical-states-with-is, gather-related-selector-rules, prune-overridden-declarations.

For complete interactive visual examples of each rule, visit the Documentation Site.

🔒 Safety Guarantees & Why CSSForge

Unlike lowering tools (e.g. LightningCSS, esbuild) or destructive minifiers (e.g. cssnano), CSSForge is built strictly for lossless forward semantic modernization:

• 🛡️ Dual-Layer Zero-Regression Engine: LightningCSS validates the AST, but a surgical Byte Patch Engine mutates only the targeted byte ranges. Untouched lines, developer comments, custom indentation, and quote styles remain 100% byte-for-byte identical.
• 🔬 Mathematical Proof Engine: Calculates exact specificity vectors (a, b, c) with zero specificity drift guarantees.
• 🚫 Refusal as a Safety Feature: Refuses transformations that would break CSS matching (such as :is() specificity inflation on lower branches).
• ✨ Multi-Selector Cluster Factoring: Automatically factors multi-branch rules sharing identical bases into clean :is() blocks with nested children.
• 🔒 Git Dirty-Tree Guard: Blocks destructive in-place replacements if uncommitted Git changes are detected.

🚫 Strict Non-Goals (What We Do NOT & Will NOT Do)

• ❌ No BEM String Concatenation (&__element): Native CSS & is a selector token (desugars to :is()), NOT a Sass string concatenator. Writing .card { &__title { } } is invalid in native CSS.
• ❌ No Specificity Inflation / Lifting: If wrapping parent selectors in :is() would artificially lift the specificity of a lower-specificity branch and alter cascade priority, CSSForge refuses the refactor.
• ❌ No Destructive Re-Serialization: We never re-format untouched code, strip comments, convert colors, or drop intentional browser fallback duplicate declarations.
• ❌ No Unsound At-Rule Moving Across Barriers: We never hoist @media / @supports blocks across intervening selector barriers if moving them would invert the cascade.

📄 License

MIT © Jayesh Mepani