Accessibility Checklist for Web Apps

Semantic HTML - Use proper heading hierarchy (h1 > h2 > h3) - Use landmark elements (main, nav, aside) - Use button for actions, a for navigation

Keyboard Navigation - All interactive elements must be focusable - Visible focus indicators (never `outline: none` without replacement) - Logical tab order - Escape key closes modals

Screen Readers - Alt text for meaningful images - aria-label for icon-only buttons - aria-live regions for dynamic content - Hide decorative elements with aria-hidden

Color & Contrast - Minimum 4.5:1 contrast ratio for normal text - Minimum 3:1 for large text - Never convey information with color alone