About CSS Reference

CSS Reference is a free, independent online documentation project covering 841+ CSS properties, pseudo-classes, pseudo-elements, at-rules, functions, selectors, and units across 21 categories, from layout and the box model to color, typography, animation, and transforms. The goal is simple: every page should answer the questions a developer actually has when they look something up — what the syntax is, which values are accepted and what each one does, what a realistic example looks like, and which browsers support the feature. Alongside the per-property reference, the site includes 68 long-form guides and 30 blog articles. Everything runs locally in your browser, there is no account and no paywall, and the content is maintained to track the current CSS specifications.