Accessibility — WCAG 2.2 AA

Accessibility (WCAG 2.2 AA)

LocusBIM is designed and tested against the WCAG 2.2 Level AA contrast and interaction standards. Verification runs on every code change via automated tests against the brand color specification — not a one-time audit.

What's covered

• Color contrast — every documented text-on-background pairing in the brand spec is verified per-theme via the WCAG relative luminance formula. Both dark mode and light mode are tested separately on every PR. Primary CTA buttons clear AA for the bold-text threshold; body text clears AA for normal text.
• Theme support — the entire interface flips between warm-dark and warm-cream via Home → Preferences → Appearance. The OS-level prefers-color-scheme setting is respected when no explicit choice is set. PDFs and 3D scenes always render in their native colors regardless of the chosen UI theme.
• Keyboard navigation — every menu, dialog, dropdown, and toggle is reachable and operable by keyboard. Escape closes any open menu / popover / modal. Focus rings render in copper (`--state-focus-ring`) at 2px for clear visibility against both light and dark surfaces.
• Reduced motion — animations are short (≤ 150 ms) and never the only channel carrying meaning. The khatam loaders cap their rotation speed at accessibility-friendly thresholds.
• Screen reader support — interactive controls carry aria-label / aria-pressed / aria-expanded as appropriate. Dialogs use role="dialog". Status changes (sync state, AI loading) use role="status" so they're announced when they change.
• Component vocabulary — every form input is a spec-defined component (TextField, NumericStepper, Dropdown, Toggle, SegmentedControl) so behavior is consistent across the app. Native <select> is replaced with a custom dropdown that respects all the above.

What's not yet covered

• Screen reader sweep — narrator coverage is correct for the spec components, but the long-tail of dialogs has been spot-checked rather than fully audited. If you encounter a screen reader gap, please email accessibility@locusbim.com.
• High-contrast mode — Windows / GNOME high-contrast accessibility modes display in the brand palette today; native HC overrides aren't yet honored. Roadmapped.
• Captions / transcripts — no audio or video in the app today, so this isn't currently relevant; will be added if it ever becomes so.

How we verify

Three automated test tiers run on every pull request before merge:

• Tier 1 — hex lint: walks every component file and fails if a literal color appears outside a small, spec-rule-cited carve-out list (Three.js material colors, persisted user content, etc.). Catches drift like a button being styled with a Tailwind hex instead of a brand token.
• Tier 2 — WCAG contrast: 35 hand-curated pairings plus every X on Y: ratio (label) claim parsed automatically from the brand spec document. Each is verified per-theme via the relative-luminance formula. Drift in either the spec or the implementation fails the build.
• Tier 3 — token misuse: static-source analysis catching the patterns render-time tests would find — for example, the disabled-control color appearing on a body-text label is flagged as drift.