Document Markup. HTML and CSS, head-on.

What each markup language is for, where it lives in a web stack, and why JSON ate XML for breakfast. The 30,000-foot view before we dive into HTML.

DOCTYPE, head, body, meta tags, and the semantic elements that tell screen readers and search engines what's actually a heading, a nav, a section, or an article.

Anchor tags and relative vs absolute URLs, images with alt and srcset, raster vs vector, and the video/audio elements that replaced Flash.

Input types, labels, validation, GET vs POST, and the accessibility rules that make forms actually usable. Plus the few attributes that prevent 90% of form bugs.

Element, class, ID, attribute, and combinator selectors. How specificity decides who wins. The cascade in 60 seconds. Why your style isn't applying.

Content, padding, border, margin. Block vs inline. Position, flex, grid — what to reach for when. The four layout modes that build every page on the web.

Font stacks, web fonts, the rem unit, contrast, semantic markup as accessibility, ARIA when you need it, and the responsive patterns from Unit 1 in real CSS.