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Accessibility

ui/docs/design-system/accessibility.md

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Accessibility

OpenClaw targets WCAG 2.1 AA. This checklist applies to every UI component — use it when building new components and during PR review.


Contrast Minimums

ContextMinimum RatioNotes
Normal body text (< 18px / < 14px bold)4.5:1Use --text (#d4d4d8) or stronger on --bg
Large text (≥ 18px regular / ≥ 14px bold)3:1Headings in chat thread
UI component boundaries (inputs, buttons)3:1Border colours against adjacent background
Focus indicators3:1 (AA)--focus-ring / --focus-glow already compliant
Placeholder textBest-effort ≥3:1--muted (#838387) is ~5:1 on --bg — acceptable

Verify with WebAIM Contrast Checker or browser DevTools accessibility panel.


Checklist

1. Focus Visible

  • All interactive elements have a visible :focus-visible style
  • Use --focus-ring box-shadow pattern from base.css — do not remove the outline without replacing it
  • Never use outline: none alone; replace with box-shadow: var(--focus-ring) and outline: none
css
/* Correct pattern */
.my-button:focus-visible {
  outline: none;
  box-shadow: var(--focus-ring);
}

2. Minimum Tap / Click Target Size

  • All interactive controls are ≥ 44×44px on mobile / touch targets
  • Icon-only buttons add invisible padding to reach 44px (min-width: 44px; min-height: 44px)
  • Verify on the mobile breakpoint (@media (max-width: 768px))
  • A visually-hidden skip link (#skip-to-main) is present in the document root
  • The link becomes visible on focus
  • Target element has tabindex="-1" to accept programmatic focus
html
<a id="skip-to-main" href="#main-content" class="skip-link">Skip to main content</a>
css
.skip-link {
  position: absolute;
  left: -9999px;
  top: 0;
  z-index: 9999;
}
.skip-link:focus {
  left: 1rem;
  top: 1rem;
  /* ... visible styles */
}

4. Focus Trap

  • Modal dialogs trap focus inside while open (Tab/Shift+Tab cycle within the modal)
  • Closing the modal returns focus to the trigger element
  • Escape key closes the modal

5. ARIA Labels

  • Icon-only buttons have aria-label describing the action (not the icon name)
  • Progress bars use role="progressbar" with aria-valuenow, aria-valuemin, aria-valuemax
  • Live regions updating async content use aria-live="polite" (or "assertive" for critical alerts)
  • Decorative SVG icons have aria-hidden="true"
html
<!-- Correct: icon button -->
<button aria-label="Send message">
  <svg aria-hidden="true"><!-- ... --></svg>
</button>

<!-- Correct: progress bar -->
<div
  role="progressbar"
  aria-valuenow="42"
  aria-valuemin="0"
  aria-valuemax="100"
  aria-label="Context window usage"
>
  <div style="width: 42%"></div>
</div>

6. Tab Role Pattern

When building a tab interface:

  • Tab container: role="tablist"
  • Each tab: role="tab", aria-selected="true|false", aria-controls="panel-id"
  • Each panel: role="tabpanel", id matching aria-controls, aria-labelledby pointing to its tab
  • Keyboard: Arrow keys move between tabs; Tab moves into the panel; Shift+Tab exits
html
<div role="tablist" aria-label="Main navigation">
  <button role="tab" aria-selected="true" aria-controls="chat-panel" id="chat-tab">Chat</button>
  <button role="tab" aria-selected="false" aria-controls="settings-panel" id="settings-tab">
    Settings
  </button>
</div>
<div role="tabpanel" id="chat-panel" aria-labelledby="chat-tab"><!-- ... --></div>
<div role="tabpanel" id="settings-panel" aria-labelledby="settings-tab" hidden><!-- ... --></div>

7. Reduced Motion

  • No animation plays without being suppressible via prefers-reduced-motion
  • The global reset in base.css covers transitions — test with "Reduce motion" enabled in OS settings
  • Infinite loaders (shimmer, spinners) have explicit animation: none in reduced-motion context

8. Semantic HTML

  • Use native elements (<button>, <a>, <input>) before adding ARIA to <div> / <span>
  • Headings (<h1><h6>) reflect document hierarchy — do not skip levels
  • Lists of items use <ul> / <ol> + <li>, not chains of <div>

Testing Tools

ToolPurpose
Chrome DevTools → Accessibility tabInspect ARIA tree, contrast
axe DevTools (browser extension)Automated WCAG audit
macOS VoiceOver (Cmd+F5)Screen reader smoke test
prefers-reduced-motion: reduce (DevTools → Rendering)Verify animation suppression
Keyboard-only navigationTab through entire UI without mouse