accessibility

原文涵盖的主题

• Accessibility (a11y)
• WCAG Principles: POUR
• Conformance levels
• Perceivable
• Text alternatives (1.1)
• Color contrast (1.4.3, 1.4.6)
• Media alternatives (1.2)
• Operable

Comprehensive accessibility guidelines based on WCAG 2.1 and Lighthouse accessibility audits. Goal: make content usable by everyone, including people with disabilities. | Principle | Description | |-----------|-------------| | Perceivable | Content can be perceived through different senses | | Operable | Interface can be operated by all users | | Understandable | Content and interface are understandable | | Robust | Content works with assistive technologies | | Level | Requirement | Target | |-------|-------------|--------| | A | Minimum accessibility | Must pass | | AA | Standard compliance | Should pass (legal requirement in many jurisdictions) | | AAA | Enhanced accessibility | Nice to have | -- Images require alt text: Icon buttons need accessible names: Visually hidden class: | Text Size | AA minimum | AAA enhanced | |-----------|------------|--------------| | Normal text (< 18px / < 14px bold) | 4.5:1 | 7:1 | | Large text (≥ 18px / ≥ 14px bold) | 3:1 | 4.5:1 | | UI components & graphics | 3:1 | 3:1 | Don't rely on color alone: -- All functionality must be keyboard accessible: No keyboard traps: -- -- Prefer native elements: When ARIA is needed: -- [ ] Keyboard navigation: Tab

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