HTML, CSS and JavaScript, every part working.

Each card is a live specimen with its exact source underneath. Nothing loads from the network; the whole tour is this one file. Filter with the search box, open any source, re-run any script.

HTMLspecimens of structure: semantics, forms, media, embedding CSSspecimens of presentation: cascade, layout, color, motion JavaScriptspecimens of behaviour: the language, then the browser APIs

HTML

Markup is shown exactly as written. Entities, comments and attributes stay literal in the source view and render in the live view.

CSS

Each specimen carries its own <style> block, scoped by a class, so the source view is the whole story. Many are interactive: hover, resize, or drag the sliders.

JavaScript

Each specimen is a function whose body is the source you see. Inside it, log() prints to the card, log.html() mounts markup and returns the element, and signal aborts when you re-run. Cards run the first time they scroll into view.