The five checks
- Keyboard reachable — can I Tab to it and operate it with Enter/Space/Arrows? A hover-only interaction is a bug.
- Focus visible — does the browser's focus ring survive your border-radius and colour changes? Never remove outlines without a visible replacement.
- Contrast AA — body text 4.5:1, large text 3:1. Watch dim captions: that 'subtle' #9AA text on #0B0D14 fails AA at small sizes.
- Reduced motion — prefers-reduced-motion must produce a calmer-but-present state, not a frozen or broken one.
- Announced state — switches need role/aria-checked; loaders need role=status/aria-live; count-ups should reveal their final value to screen readers immediately.
Two traps specific to animated UI
The first trap: decorative motion that carries meaning. If a number counts up, the visual is decoration — the *meaning* must exist in the DOM from the start (the final value, read out loud immediately).
The second trap: hover-only affordances. Anything revealed on hover must also be discoverable by keyboard — that usually means 'make it a real button or link, or expose the action another way'.
Our bar
We publish the automated a11y score on every asset card and re-check with a human pass before 'Verified'. If a submitted asset can't reach ~90, it doesn't ship — that's the quality gate that keeps this library from becoming a pile of pretty failures.