Vibecosystem accessibility-patterns

WCAG 2.2 AA compliance, ARIA patterns, keyboard navigation, screen reader optimization

install
source · Clone the upstream repo
git clone https://github.com/vibeeval/vibecosystem
Claude Code · Install into ~/.claude/skills/
T=$(mktemp -d) && git clone --depth=1 https://github.com/vibeeval/vibecosystem "$T" && mkdir -p ~/.claude/skills && cp -r "$T/skills/accessibility-patterns" ~/.claude/skills/vibeeval-vibecosystem-accessibility-patterns && rm -rf "$T"
manifest: skills/accessibility-patterns/SKILL.md
source content

Accessibility Patterns

WCAG 2.2 AA Requirements

Perceivable

KriterKuralKontrol
1.1.1Non-text content alt text
<img alt="description">
1.3.1Semantic HTMLHeadings, landmarks, lists
1.4.3Color contrast4.5:1 normal text, 3:1 large
1.4.11UI component contrast3:1 borders, icons

Operable

KriterKuralKontrol
2.1.1Keyboard accessibleTab, Enter, Space, Escape
2.4.3Focus orderLogical tab sequence
2.4.7Focus visibleVisible focus indicator
2.5.8Target sizeMin 24x24px (44x44px önerilir)

Understandable

KriterKuralKontrol
3.1.1Language of page
<html lang="tr">
3.2.1On focusNo unexpected context change
3.3.1Error identificationClear error messages
3.3.2Labels or instructionsForm labels visible

ARIA Patterns

<!-- Dialog -->
<div role="dialog" aria-modal="true" aria-labelledby="title">
  <h2 id="title">Confirm</h2>
  <button aria-label="Close dialog">×</button>
</div>

<!-- Tabs -->
<div role="tablist">
  <button role="tab" aria-selected="true" aria-controls="panel1">Tab 1</button>
  <button role="tab" aria-selected="false" aria-controls="panel2">Tab 2</button>
</div>
<div role="tabpanel" id="panel1">Content 1</div>

<!-- Live region (dynamic updates) -->
<div aria-live="polite" aria-atomic="true">
  3 new messages
</div>

Keyboard Navigation

// Focus trap (modal/dialog)
function useFocusTrap(ref: RefObject<HTMLElement>) {
  useEffect(() => {
    const focusable = ref.current?.querySelectorAll(
      'button, [href], input, select, textarea, [tabindex]:not([tabindex="-1"])'
    )
    const first = focusable?.[0] as HTMLElement
    const last = focusable?.[focusable.length - 1] as HTMLElement

    function handleKeyDown(e: KeyboardEvent) {
      if (e.key !== 'Tab') return
      if (e.shiftKey && document.activeElement === first) {
        e.preventDefault(); last.focus()
      } else if (!e.shiftKey && document.activeElement === last) {
        e.preventDefault(); first.focus()
      }
    }
    ref.current?.addEventListener('keydown', handleKeyDown)
    first?.focus()
    return () => ref.current?.removeEventListener('keydown', handleKeyDown)
  }, [ref])
}

Skip Links

<a href="#main-content" class="skip-link">Skip to main content</a>
<!-- ... navigation ... -->
<main id="main-content">...</main>

<style>
.skip-link {
  position: absolute;
  top: -40px;
  left: 0;
  z-index: 100;
}
.skip-link:focus { top: 0; }
</style>

Motion Preferences

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    transition-duration: 0.01ms !important;
  }
}

Testing

# axe-core (automated)
npx @axe-core/cli https://localhost:3000

# Lighthouse accessibility audit
lighthouse --only-categories=accessibility https://localhost:3000

Checklist

  • Semantic HTML (headings, landmarks, lists)
  • Alt text on all images
  • Color contrast 4.5:1 (text), 3:1 (UI)
  • Keyboard navigable (tab order logical)
  • Focus visible indicator
  • Skip link to main content
  • Form labels and error messages
  • ARIA roles where needed
  • prefers-reduced-motion respected
  • axe-core test pass

Anti-Patterns

  • <div onclick>
    instead of
    <button>
  • Color-only information (add icon/text)
  • Auto-playing video/audio
  • Removing focus outline without replacement
  • Using ARIA when native HTML suffices