FrameBaseCSS documentation

Build semantic sites from verified contracts

Start with one CSS link, choose a theme strategy, then copy only the HTML contract required by the page.

CSS-only coreMITDeveloper and AI ready

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Markup, variants, states, responsive behavior, accessibility, and JavaScript ownership.

Fixed dark, fixed light, automatic system preference, and custom token overrides.

Author responsibilities and the guarantees CSS can and cannot provide.

Observed tests, feature-derived targets, fallbacks, and progressive enhancement.

A real right-to-left document using the same component API.

The original mega-demo remains the broad offline rendering and contract reference.