accessibility

# Accessibility (a11y) Comprehensive accessibility guidelines based on WCAG 2.1 and Lighthouse accessibility audits. Goal: make content usable by everyone, including people with disabilities. ## WCAG Principles: POUR | Principle | Description | |-----------|-------------| | **P**erceivable | Content can be perceived through different senses | | **O**perable | Interface can be operated by all users | | **U**nderstandable | Content and interface are understandable | | **R**obust | Content works with assistive technologies | ## Conformance levels | Level | Requirement | Target | |-------|-------------|--------| | **A** | Minimum accessibility | Must pass | | **AA** | Standard compliance | Should pass (legal requirement in many jurisdictions) | | **AAA** | Enhanced accessibility | Nice to have | --- ## Perceivable ### Text alternatives (1.1) **Images require alt text:** ```html <!-- ❌ Missing alt --> <img src="chart.png"> <!-- ✅ Descriptive alt --> <img src="chart.png" alt="Bar chart showing 40% increase in Q3 sales"> <!-- ✅ Decorative image (empty alt) --> <img src="decorative-border.png" alt="" role="presentation"> <!-- ✅ Complex image with longer description --> <figure> <img src="infographic.png" alt="2024 market trends infographic" aria-describedby="infographic-desc"> <figcaption id="infographic-desc"> <!-- Detailed description --> </figcaption> </figure> ``` **Icon buttons need accessible names:** ```html <!-- ❌ No accessible name --> <button>...