Audit and improve web accessibility following WCAG 2.2 guidelines and best practices.

• Covers all four WCAG principles (Perceivable, Operable, Understandable, Robust) with conformance levels A, AA, and AAA
• Includes code examples for text alternatives, color contrast, keyboard navigation, focus management, form labels, error handling, and ARIA usage
• Provides testing checklist with automated tools (Lighthouse, axe-core) and manual testing procedures for keyboard, screen reader, zoom, and motion preferences
• Highlights critical issues (missing labels, alt text, contrast, keyboard traps) and new WCAG 2.2 criteria like target size, focus visibility, dragging alternatives, and accessible authentication