timeline-frontend/ACCESSIBILITY_CHECKLIST.md

# Accessibility Checklist

This document provides a checklist for ensuring accessibility compliance across the Timeline application.

## General Principles

- ✅ All interactive elements are keyboard accessible
- ✅ Focus indicators are visible for keyboard navigation
- ✅ Color is not the only means of conveying information
- ✅ Text has sufficient contrast ratio (WCAG AA: 4.5:1 for normal text, 3:1 for large text)
- ✅ Touch targets are at least 44x44px
- ✅ Content is responsive and works on mobile devices

## Semantic HTML

- ✅ Use semantic HTML elements (`<nav>`, `<main>`, `<article>`, `<section>`, etc.)
- ✅ Headings follow logical hierarchy (h1 → h2 → h3)
- ✅ Lists use proper list markup (`<ul>`, `<ol>`, `<li>`)
- ✅ Forms use proper form elements with labels
- ✅ Buttons use `<button>` element (not `<div>` with click handlers)
- ✅ Links use `<a>` element with proper href

## ARIA Attributes

### Required ARIA Labels

- ✅ Interactive elements without visible text have `aria-label`
- ✅ Icon buttons have descriptive `aria-label`
- ✅ Form inputs have associated labels or `aria-label`
- ✅ Landmarks have `aria-label` when multiple of same type exist

### ARIA States

- ✅ Expandable elements use `aria-expanded`
- ✅ Selected items use `aria-selected`
- ✅ Checked items use `aria-checked`
- ✅ Disabled elements use `aria-disabled`
- ✅ Loading states use `aria-busy`
- ✅ Hidden content uses `aria-hidden`

### ARIA Roles

- ✅ Custom widgets have appropriate roles
- ✅ Live regions use `aria-live` for dynamic content
- ✅ Dialogs use `role="dialog"` and `aria-modal="true"`
- ✅ Alerts use `role="alert"` or `aria-live="assertive"`

## Keyboard Navigation

### Focus Management

- ✅ Focus order follows logical reading order
- ✅ Focus is trapped in modals/dialogs
- ✅ Focus returns to trigger element when modal closes
- ✅ Skip links provided for main content
- ✅ No keyboard traps (user can always navigate away)

### Keyboard Shortcuts

- ✅ Enter/Space activates buttons and links
- ✅ Escape closes modals and dropdowns
- ✅ Arrow keys navigate lists and menus
- ✅ Tab/Shift+Tab moves between focusable elements
- ✅ Home/End navigate to first/last item in lists

## Forms

- ✅ All inputs have associated labels
- ✅ Required fields are marked with `required` attribute
- ✅ Error messages are associated with inputs using `aria-describedby`
- ✅ Form validation provides clear error messages
- ✅ Success messages are announced to screen readers
- ✅ Placeholder text is not used as labels

## Images

- ✅ All images have `alt` text
- ✅ Decorative images have empty `alt=""` or `aria-hidden="true"`
- ✅ Complex images have detailed descriptions
- ✅ Icons have text alternatives or `aria-label`

## Media

- ✅ Videos have captions/subtitles
- ✅ Audio content has transcripts
- ✅ Auto-playing media can be paused
- ✅ Media controls are keyboard accessible

## Color and Contrast

- ✅ Text contrast meets WCAG AA standards (4.5:1)
- ✅ Large text contrast meets WCAG AA standards (3:1)
- ✅ UI components have sufficient contrast (3:1)
- ✅ Focus indicators have sufficient contrast
- ✅ Information is not conveyed by color alone

## Responsive Design

### Mobile (< 768px)

- ✅ Content is readable without horizontal scrolling
- ✅ Touch targets are at least 44x44px
- ✅ Text is at least 16px to prevent zoom on iOS
- ✅ Navigation is accessible on mobile
- ✅ Forms are easy to complete on mobile

### Tablet (768px - 1024px)

- ✅ Layout adapts appropriately
- ✅ Touch and mouse interactions both work
- ✅ Content is readable and usable

### Desktop (> 1024px)

- ✅ Layout uses available space effectively
- ✅ Keyboard navigation works smoothly
- ✅ Hover states are visible

## Motion and Animation

- ✅ Animations respect `prefers-reduced-motion`
- ✅ Auto-playing animations can be paused
- ✅ Animations don't cause seizures (no flashing > 3 times/second)
- ✅ Parallax effects have alternatives

## Screen Reader Testing

### Test with:

- ✅ NVDA (Windows)
- ✅ JAWS (Windows)
- ✅ VoiceOver (macOS/iOS)
- ✅ TalkBack (Android)

### Verify:

- ✅ All content is announced
- ✅ Navigation is logical
- ✅ Form labels are read correctly
- ✅ Error messages are announced
- ✅ Dynamic content updates are announced
- ✅ Images have meaningful descriptions

## Component-Specific Checks

### Albums

- ✅ Album cards have descriptive labels
- ✅ Photo grid is keyboard navigable
- ✅ Drag-and-drop has keyboard alternative
- ✅ Delete confirmations are accessible

### Comments

- ✅ Comment form has proper labels
- ✅ Character counter is announced
- ✅ Submit button is keyboard accessible
- ✅ Edit/delete buttons have clear labels
- ✅ New comments are announced

### Reactions

- ✅ Reaction buttons have descriptive labels
- ✅ Current user reaction is indicated
- ✅ Reaction counts are announced
- ✅ Reaction picker is keyboard accessible

### Statistics

- ✅ Charts have text alternatives
- ✅ Data tables are properly structured
- ✅ Trends are described in text

### Theme Customizer

- ✅ Theme options are keyboard accessible
- ✅ Color picker has keyboard support
- ✅ Preview updates are announced

### Profile Editor

- ✅ Cover photo upload is keyboard accessible
- ✅ Crop tool has keyboard controls
- ✅ Custom fields are properly labeled
- ✅ Visibility toggles are clear

## Testing Tools

### Automated Testing

- ✅ axe DevTools
- ✅ WAVE
- ✅ Lighthouse Accessibility Audit
- ✅ Pa11y

### Manual Testing

- ✅ Keyboard-only navigation
- ✅ Screen reader testing
- ✅ Zoom to 200%
- ✅ High contrast mode
- ✅ Color blindness simulation

## Resources

- [WCAG 2.1 Guidelines](https://www.w3.org/WAI/WCAG21/quickref/)
- [Ant Design Accessibility](https://ant.design/docs/spec/accessibility)
- [MDN Accessibility](https://developer.mozilla.org/en-US/docs/Web/Accessibility)
- [WebAIM](https://webaim.org/)

## Notes

- This checklist is based on WCAG 2.1 Level AA standards
- Regular accessibility audits should be conducted
- User testing with people with disabilities is recommended
- Accessibility is an ongoing process, not a one-time task