| Basic |
| MDN: CSS Styling Basics |
Getting started |
Syntax, selectors, the box model, values and units - the essential foundation for everything else. |
| web.dev: Learn CSS |
Getting started |
Google-authored course; one chapter per concept with interactive code panels. Covers the full language systematically. |
| CSS-Tricks: Complete Guide to Flexbox |
Layout |
Visual reference covering every flexbox container and item property with diagrams and live examples. |
| CSS-Tricks: Complete Guide to Grid |
Layout |
Visual reference for all grid container and item properties. The go-to for quick lookups while building grid layouts. |
| Intermediate |
| MDN: CSS Layout |
Layout |
Module covering normal flow, flexbox, grid, positioning, and responsive design in sequence. |
| MDN: Positioning |
Positioning |
Step-by-step coverage of all five position values with live examples; explains containing blocks and stacking. |
| MDN: Understanding z-index |
Stacking |
Four-part series on stacking order, stacking contexts, and the common z-index bugs that arise from them. |
| web.dev: Responsive Design |
Responsive |
Media queries, fluid layouts, viewport meta, and an introduction to container queries. |
| MDN: Using CSS Transitions |
Animation |
How transitions work, which properties are animatable, timing functions, and combining multiple transitions. |
| Advanced |
| MDN: CSS Custom Properties |
Variables |
Inheritance rules, fallback values, invalid-at-computed-value time, and reading/writing from JavaScript. |
| MDN: CSS Cascade Layers |
Cascade |
Full @layer tutorial with ordering rules, nested layers, and interaction with !important. |
| CSS-Tricks: Cascade Layers |
Cascade |
Practical guide to @layer with real-world use cases including third-party containment and utility ordering. |
| MDN: CSS Animations |
Animation |
Keyframe animations, timing functions, fill mode, direction, iteration, and compositing with transitions. |
| web.dev: Container Queries |
Responsive |
Component-scoped responsive design with @container - size, style, and state queries. |