a11y

Files (15)

• SKILL.md
• a11y-testing.md · references/
• async-content-a11y.md · references/
• cognitive-a11y.md · references/
• container-responsive-a11y.md · references/
• dialog-popover-a11y.md · references/
• flutter-a11y.md · references/
• mobile-a11y.md · references/
• motion-contrast-modes.md · references/
• nextjs-a11y.md · references/
• pwa-a11y.md · references/
• view-transitions-a11y.md · references/
• wcag3-apca.md · references/
• web-a11y.md · references/
• skill.yaml

SKILL.md (first lines)

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# A11y — Accessibility

WCAG 2.2 AAA patterns. All examples assume RTL (Hebrew/Arabic) unless noted as LTR-only.

---

## WCAG 2.2 Critical Rules

| Criterion | Level | Requirement | Common Failure |
|-----------|-------|-------------|----------------|
| 1.4.11 Non-text Contrast | AA | 3:1 ratio for UI components and focus indicators | Gray icons on white backgrounds |
| 1.4.12 Text Spacing | AA | Line height ≥1.5×, letter spacing ≥0.12×, word spacing ≥0.16× | Fixed pixel heights that clip text |
| 2.4.7 Focus Visible | AA | Focus indicator must be visible | `outline: none` without replacement |
| 2.4.11 Focus Not Obscured | AA | Focused element not entirely hidden by sticky header | Sticky nav covering focused inputs |
| 2.4.12 Focus Not Obscured | AAA | Focused element not partially hidden | |
| 2.5.3 Label in Name | A | Accessible name must contain visible label text | Icon buttons without aria-label |
| 2.5.8 Target Size | AA | Interactive targets minimum 24×24px; recommended 44×44px | Small icon-only buttons |
| 3.2.6 Consistent Help | A | Help mechanisms in consistent location across pages | |
| 3.3.7 Redundant Entry | A | Don't ask for same info twice | Re-asking for email on multi-step form |
| 3.3.8 Accessible Authentication | AA | No cognitive function test for auth | CAPTCHAs without alternative |

Rule: The 44×44px touch target minimum applies to all interactive elements on touch devices. (BLOCKING for mobile-first apps)

---

## Touch Target Size

```css
/* global.css — apply to all interactive elements */
button,
[role="button"],
a,
input[type="checkbox"],
input[type="radio"],
select {
  /* Ensure minimum touch target without changing visual size */
  min-height: 44px;
  min-width: 44px;
}

/* For icon-only buttons that must appear smaller visually */
.icon-btn {
  position: relative;
  /* Visual size: 24px */
  width: 24px;
  height: 24px;
}

.icon-btn::before {
  content: '';
  position: absolute;
  /* Touch target: 44px */
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 44px;
  height: 44px;
}
```

```typescript
// Tailwind utility for 44px touch targets
// Add to your component library:
// className="relative w-6 h-6 before:absolute before:top-1/2 before:left-1/2 before:-translate-x-1/2 before:-translate-y-1/2 before:w-11 before:h-11"
```

---

## Focus Trap Pattern

Required for: modals, drawers, date pickers, dropdown menus, mobile nav.

```typescript
// hooks/useFocusTrap.ts
import { useEffect, useRef } from 'react'

const FOCUSABLE_SELECTORS = [
  'a[href]',
  'button:not([disabled])',
  'input:not([disabled])',
  'select:not([disabled])',
  'textarea:not([disabled])',
  '[tabindex]:not([tabindex="-1"])',
].join(', ')

export function useFocusTrap(isActive: boolean) {
  const containerRef = useRef<HTMLElement>(null)
  const previousFocusRef = useRef<HTMLElement | null>(null)

  useEffect(() => {
    if (!isActive) return

    // Save currently focused element
    previousFocusRef.current = document.activeElement as HTMLElement

    const container = containerRef.current
    if (!container) return

    // Focus first focusable element
    const focusable = container.querySelectorAll<HTMLElement>(FOCUSABLE_SELECTORS)
    const first = focusable[0]
    const last = focusable[focusable.length - 1]

    first?.focus()

    const handleKeyDown = (e: KeyboardEvent) => {
      if (e.key !== 'Tab') return

      const currentFocusable = container.querySelectorAll<HTMLElement>(FOCUSABLE_SELECTORS)
      const firstEl = currentFocusable[0]
      const lastEl = currentFocusable[currentFocusable.length - 1]

      if (e.shiftKey) {
        // Shift+Tab: wrap from first to last
        if (document.activeElement === firstEl) {
          e.preventDefault()
          lastEl?.focus()

From Nadav011/apex-skills, MIT.

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