CSS
The language for styling and laying out HTML pages.
1. Introduction to CSS
What CSS is, how a rule is structured, and the three ways to attach it, with why one of them is almost always the right choice.
2. Selectors
Targeting elements by tag, class, id, or combinations of these, and how CSS decides which rule wins when two rules conflict.
3. Colors & Backgrounds
Setting text and background color by name, hex, or rgb, and what that fourth rgba number actually controls.
4. The Box Model
Content, padding, border, and margin, the four layers every element is built from, and the one setting that changes how they're measured.
5. Text & Fonts
font-family, font-size, font-weight, and text-align, and why a font-family list always needs a fallback.
6. Flexbox
Laying out a row (or column) of items with display: flex, the single most useful layout tool for everyday UI work.
7. Grid
Two-dimensional layouts with display: grid, when to reach for it instead of flexbox.
8. Positioning
static, relative, absolute, and fixed positioning, and the parent/child relationship that makes absolute positioning predictable instead of confusing.
9. Responsive Design (Media Queries)
Changing styles based on screen width with @media, and why the mobile-first approach beats designing desktop-first.
10. Transitions & Hover Effects
Animating property changes smoothly with the transition property, and why it needs to be paired with :hover to actually be noticed.