CSS Specifications
Comprehensive guide to CSS specifications from the W3C CSS Working Group. Learn modern CSS features, understand specification statuses, and master the latest web styling standards.
Understanding Specification Status
Recommendation
Stable, widely implemented
Candidate Rec
Testing phase, stable API
Working Draft
In development, may change
Note
Informational, guidance
CSS Modules by Category
CSS Fundamentals
Core CSS specifications and syntax foundation
Key Specifications
CSS 2.1
The stable foundation of CSS with all interoperably implemented features
CSS Snapshots 2024
Current state of CSS - distinguishing stable from experimental features
CSS Syntax Level 3
How to parse CSS, including error handling and recovery
CSS Values and Units Level 4
Common values and units used throughout CSS specifications
Selectors & Media Queries
Advanced selectors and responsive design queries
Key Specifications
Selectors Level 4
Extended selectors including :has(), :is(), :where() and more
Media Queries Level 4
Enhanced media features for modern devices and capabilities
CSS Conditional Rules Level 4
Testing for selector support and combining conditions
Media Queries Level 5
Ambient light sensing and JavaScript availability testing
Layout & Positioning
Modern layout systems and positioning techniques
Key Specifications
CSS Grid Layout Level 2
Two-dimensional grid-based layout system with subgrids
CSS Flexible Box Layout Level 1
One-dimensional layout method for arranging items in rows or columns
CSS Multi-column Layout Level 1
Flowing content across multiple columns like newspapers
CSS Anchor Positioning
Position elements relative to other elements anywhere on the page
Visual & Animations
Visual effects, colors, and animation specifications
Key Specifications
CSS Color Level 4
Extended color spaces, new color functions, and relative colors
CSS Animations Level 1
Keyframe-based animations with timing functions and delays
CSS Transitions Level 1
Smooth transitions between property value changes
CSS Transforms Level 1
2D and 3D transformations including rotation, scaling, and translation
Modern CSS Features
Cutting-edge CSS features and experimental specifications
Key Specifications
CSS Custom Properties Level 1
CSS variables for storing and reusing values throughout stylesheets
CSS Container Queries Level 1
Style elements based on the size of their containing element
CSS Nesting
Write nested CSS rules for better organization and maintainability
CSS View Transitions Level 1
Smooth transitions when content changes or pages navigate