a11y-debugging

SKILL.md

Core Concepts

Accessibility Tree vs DOM: Visually hiding an element (e.g., CSS opacity: 0) behaves differently for screen readers than display: none or aria-hidden="true". The take_snapshot tool returns the accessibility tree of the page, which represents what assistive technologies "see", making it the most reliable source of truth for semantic structure.

Reading web.dev documentation: If you need to research specific accessibility guidelines (like https://web.dev/articles/accessible-tap-targets), you can append .md.txt to the URL (e.g., https://web.dev/articles/accessible-tap-targets.md.txt) to fetch the clean, raw markdown version. This is much easier to read!

Workflow Patterns

1. Automated Audit (Lighthouse)

Start by running a Lighthouse accessibility audit to get a comprehensive baseline. This tool provides a high-level score and lists specific failing elements with remediation advice.