CSS (W3C CSS Specifications)

1. CSS snapshot

   Official list of stable CSS modules.

2. Cascade and inheritance

   Origins, importance, specificity, layers and the cascade sort order.

3. Cascade layers

   @layer ordering and layer precedence.

4. Values and units

   Lengths, percentages and math functions such as calc().

5. Custom properties

   --* properties and var() substitution.

6. Box model

   Margin, border, padding, content and box sizing.

7. Display and layout modes

   display types, inline and block formatting contexts.

8. Positioned layout

   static, relative, absolute, fixed and sticky positioning.

9. Media queries

   Media features, range syntax and preference queries.

10. Nesting

    Nested style rules and the & selector.

11. Color

    Color spaces, oklch, color-mix and system colors.

Each section links to the official page. Titles and summaries by Extra Credit; the docs belong to their authors.

• C Standard (ISO/IEC 9899)
• C++ Core Guidelines
• C++ Standard (ISO/IEC 14882)
• CSS Flexible Box Layout
• CSS Grid Layout
• DOM Standard (WHATWG)
• ECMAScript (ECMA-262)
• ECMAScript Internationalization API (ECMA-402)
• Encoding Standard (WHATWG)
• Fetch Standard (WHATWG)
• HTML Living Standard (WHATWG)
• Java Language Specification