Accessibility Skill

=== PURPOSE ===

Procedures for ensuring WCAG 2.1 AA compliance.

=== USED BY ===

=== WCAG 2.1 PRINCIPLES ===

POUR Framework:

• Perceivable - Information must be presentable
• Operable - Interface must be operable
• Understandable - Information must be understandable
• Robust - Content must work with assistive tech

=== PROCEDURE: Perceivable Checklist ===

1.1 Text Alternatives

• All images have alt text
• Decorative images have empty alt=""
• Complex images have long descriptions
• Icons have accessible names

1.2 Time-based Media

• Videos have captions
• Audio has transcripts
• Live events have captions

1.3 Adaptable

• Content structure uses semantic HTML
• Reading order is logical
• Instructions don't rely on sensory characteristics
• Orientation not restricted

1.4 Distinguishable

• Color is not sole indicator
• Audio can be controlled
• Text contrast ≥4.5:1
• Large text contrast ≥3:1
• Text can resize to 200%
• No images of text
• Content reflows at 320px
• Non-text contrast ≥3:1
• Text spacing adjustable
• Content on hover/focus dismissible

=== PROCEDURE: Operable Checklist ===

2.1 Keyboard Accessible

• All functionality via keyboard
• No keyboard traps
• Character key shortcuts can be disabled

2.2 Enough Time

• Time limits adjustable
• Moving content can be paused
• No auto-update without warning
• Re-authentication preserves data

2.3 Seizures and Physical

• No flashing >3 times/second
• Motion can be disabled

2.4 Navigable

• Skip links present
• Pages have titles
• Focus order logical
• Link purpose clear
• Multiple ways to find pages
• Headings describe content
• Focus indicator visible
• Location indicated

2.5 Input Modalities

• Touch targets ≥44x44px
• No drag-only actions
• Label in name for speech users
• Motion activation has alternatives

=== PROCEDURE: Understandable Checklist ===

3.1 Readable

• Language of page declared
• Language of parts declared

3.2 Predictable

• Focus doesn't cause context change
• Input doesn't cause unexpected change
• Navigation is consistent
• Components identified consistently

3.3 Input Assistance

• Errors identified clearly
• Labels/instructions provided
• Error suggestions given
• Error prevention for legal/financial

=== PROCEDURE: Robust Checklist ===

4.1 Compatible

• HTML is valid
• Name, role, value available
• Status messages announced

=== PROCEDURE: Testing Tools ===

Automated Testing:

# axe-core (browser extension or CLI)
npx @axe-core/cli https://example.com

# Pa11y
npx pa11y https://example.com

# Lighthouse
npx lighthouse https://example.com --only-categories=accessibility

Manual Testing:

1. Keyboard navigation - Tab through entire page
2. Screen reader - Test with NVDA/VoiceOver/JAWS
3. Zoom - Test at 200% and 400%
4. Color blindness - Use simulator tools
5. Motion - Test with reduced motion enabled

=== PROCEDURE: Audit Report ===

# Accessibility Audit Report

**URL/Feature:** [What was audited]
**Standard:** WCAG 2.1 AA
**Auditor:** @ux-designer
**Date:** YYYY-MM-DD

## Summary
- Total issues: X
- Critical: X
- Serious: X
- Moderate: X
- Minor: X

## Tool Results
- axe-core: X issues
- Pa11y: X issues
- Lighthouse score: XX/100

## Manual Testing
- Keyboard: [PASS/FAIL]
- Screen reader: [PASS/FAIL]
- Zoom: [PASS/FAIL]

## Issues

### [Critical] Missing alt text on product images
**WCAG:** 1.1.1 Non-text Content
**Location:** /products page
**Impact:** Screen reader users cannot identify products
**Remediation:** Add descriptive alt text to all product images
**Code example:**
```html
<!-- Before -->
<img src="product.jpg">
<!-- After -->
<img src="product.jpg" alt="Blue cotton t-shirt, front view">

[Serious] Insufficient color contrast

WCAG: 1.4.3 Contrast (Minimum) Location: Footer links Current ratio: 2.8:1 Required ratio: 4.5:1 Remediation: Change text color from #999 to #767676

Compliance Summary

=== PROCEDURE: Common Fixes ===

**Images:**
```html
<!-- Informative -->
<img src="chart.png" alt="Sales increased 25% in Q4">

<!-- Decorative -->
<img src="decoration.png" alt="" role="presentation">

<!-- Complex -->
<figure>
  <img src="diagram.png" alt="System architecture">
  <figcaption>Detailed description...</figcaption>
</figure>

Forms:

<label for="email">Email address</label>
<input id="email" type="email" aria-describedby="email-hint">
<span id="email-hint">We'll never share your email</span>

<!-- Error state -->
<input id="email" aria-invalid="true" aria-describedby="email-error">
<span id="email-error" role="alert">Please enter a valid email</span>

Focus:

:focus {
  outline: 2px solid #005fcc;
  outline-offset: 2px;
}

:focus:not(:focus-visible) {
  outline: none; /* Remove for mouse users */
}

:focus-visible {
  outline: 2px solid #005fcc;
  outline-offset: 2px;
}

=== RELATED SKILLS ===