Accessibility

The gate

checkThemeContrast(resolveTheme(theme), { exceptions }) from uxdsl/theme — the same call uxdsl theme --contrast makes in a terminal, where a failing pair exits 1. It checks every text, placeholder and border pair the Surface, Button and Input engines define, in light and dark mode, at every configured breakpoint, against 4.5:1 for text and 3:1 for borders. Switch the theme in the header and the report below is recomputed; the browser walk compares it with the same call in Node.

It checks the colors a theme resolves to, not a rendered page: it is not an accessibility certification, and it says nothing about focus order, labels or semantics, which stay the job of your HTML.

Exceptions are patterns, and are listed

The packaged base theme and this site's four themes pass with zero failing pairs. Passing is not "every pair passed": uxdsl/theme/base.contrast-exceptions.json ships three pattern records, one per canvas-identity family — surface, light, dark — used as a tone on a role that draws it on the page itself (outlined, flat, underline, a contained Input's focus border). That draws the canvas color on the canvas, and no value of the family can fix it without changing what the family is. Each excepted pair is listed below with its real ratio and the record that covers it; a pattern that covers nothing, a malformed record or a duplicate id fails the verdict.

{ "id": "canvas-identity-tone-light", "tone": "light", "against": "ambient", "reason": "…" }

A project passes its own exceptions file with { exceptions }. Use surface, light and dark as a tone only on contained, where they are a fill with their own contrast on top — that text pair is still checked.