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+# Accessibility Checklist
+
+Quick reference for WCAG 2.1 AA compliance. Use alongside the `frontend-ui-engineering` skill.
+
+## Table of Contents
+
+- [Essential Checks](#essential-checks)
+- [Common HTML Patterns](#common-html-patterns)
+- [Testing Tools](#testing-tools)
+- [Quick Reference: ARIA Live Regions](#quick-reference-aria-live-regions)
+- [Common Anti-Patterns](#common-anti-patterns)
+
+## Essential Checks
+
+### Keyboard Navigation
+- [ ] All interactive elements focusable via Tab key
+- [ ] Focus order follows visual/logical order
+- [ ] Focus is visible (outline/ring on focused elements)
+- [ ] Custom widgets have keyboard support (Enter to activate, Escape to close)
+- [ ] No keyboard traps (user can always Tab away from a component)
+- [ ] Skip-to-content link at top of page - visible (at least) on keyboard focus
+- [ ] Modals trap focus while open, return focus on close
+
+### Screen Readers
+- [ ] All images have `alt` text (or `alt=""` for decorative images)
+- [ ] All form inputs have associated labels (`<label>` or `aria-label`)
+- [ ] Buttons and links have descriptive text (not "Click here")
+- [ ] Icon-only buttons have `aria-label`
+- [ ] Page has one `<h1>` and headings don't skip levels
+- [ ] Dynamic content changes announced (`aria-live` regions)
+- [ ] Tables have `<th>` headers with scope
+
+### Visual
+- [ ] Text contrast ≥ 4.5:1 (normal text) or ≥ 3:1 (large text, 18px+)
+- [ ] UI components contrast ≥ 3:1 against background
+- [ ] Color is not the only way to convey information
+- [ ] Text resizable to 200% without breaking layout
+- [ ] No content that flashes more than 3 times per second
+
+### Forms
+- [ ] Every input has a visible label
+- [ ] Required fields indicated (not by color alone)
+- [ ] Error messages specific and associated with the field
+- [ ] Error state visible by more than color (icon, text, border)
+- [ ] Form submission errors summarized and focusable
+- [ ] Known fields use autocomplete (for example `type="email" autocomplete="email"`)
+
+### Content
+- [ ] Language declared (`<html lang="en">`)
+- [ ] Page has a descriptive `<title>`
+- [ ] Links distinguish from surrounding text (not by color alone)
+- [ ] Touch targets ≥ 44x44px on mobile
+- [ ] Meaningful empty states (not blank screens)
+
+## Common HTML Patterns
+
+### Buttons vs. Links
+
+```html
+<!-- Use <button> for actions -->
+<button onClick={handleDelete}>Delete Task</button>
+
+<!-- Use <a> for navigation -->
+<a href="/tasks/123">View Task</a>
+
+<!-- NEVER use div/span as buttons -->
+<div onClick={handleDelete}>Delete</div>  <!-- BAD -->
+```
+
+### Form Labels
+
+```html
+<!-- Explicit label association -->
+<label htmlFor="email">Email address</label>
+<input id="email" type="email" required />
+
+<!-- Implicit wrapping -->
+<label>
+  Email address
+  <input type="email" required />
+</label>
+
+<!-- Hidden label (visible label preferred) -->
+<input type="search" aria-label="Search tasks" />
+```
+
+### ARIA Roles
+
+```html
+<!-- Navigation -->
+<nav aria-label="Main navigation">...</nav>
+<nav aria-label="Footer links">...</nav>
+
+<!-- Status messages -->
+<div role="status" aria-live="polite">Task saved</div>
+
+<!-- Alert messages -->
+<div role="alert">Error: Title is required</div>
+
+<!-- Modal dialogs -->
+<dialog aria-modal="true" aria-labelledby="dialog-title">
+  <h2 id="dialog-title">Confirm Delete</h2>
+  ...
+</dialog>
+
+<!-- Loading states -->
+<div aria-busy="true" aria-label="Loading tasks">
+  <Spinner />
+</div>
+```
+
+### Accessible Lists
+
+```html
+<ul role="list" aria-label="Tasks">
+  <li>
+    <input type="checkbox" id="task-1" aria-label="Complete: Buy groceries" />
+    <label htmlFor="task-1">Buy groceries</label>
+  </li>
+</ul>
+```
+
+## Testing Tools
+
+```bash
+# Automated audit
+npx axe-core          # Programmatic accessibility testing
+npx pa11y             # CLI accessibility checker
+
+# In browser
+# Chrome DevTools → Lighthouse → Accessibility
+# Chrome DevTools → Elements → Accessibility tree
+
+# Screen reader testing
+# macOS: VoiceOver (Cmd + F5)
+# Windows: NVDA (free) or JAWS
+# Linux: Orca
+```
+
+## Quick Reference: ARIA Live Regions
+
+| Value | Behavior | Use For |
+|-------|----------|---------|
+| `aria-live="polite"` | Announced at next pause | Status updates, saved confirmations |
+| `aria-live="assertive"` | Announced immediately | Errors, time-sensitive alerts |
+| `role="status"` | Same as `polite` | Status messages |
+| `role="alert"` | Same as `assertive` | Error messages |
+
+## Common Anti-Patterns
+
+| Anti-Pattern | Problem | Fix |
+|---|---|---|
+| `div` as button | Not focusable, no keyboard support | Use `<button>` |
+| Missing `alt` text | Images invisible to screen readers | Add descriptive `alt` |
+| Color-only states | Invisible to color-blind users | Add icons, text, or patterns |
+| Autoplaying media | Disorienting, can't be stopped | Add controls, don't autoplay |
+| Custom dropdown with no ARIA | Unusable by keyboard/screen reader | Use native `<select>` or proper ARIA listbox |
+| Removing focus outlines | Users can't see where they are | Style outlines, don't remove them |
+| Empty links/buttons | "Link" announced with no description | Add text or `aria-label` |
+| `tabindex > 0` | Breaks natural tab order | Use `tabindex="0"` or `-1` only |