Light/Dark Mode Accessibility Skill

Canonical source: examples/LIGHT_DARK_MODE_ACCESSIBILITY_BEST_PRACTICES.md in mgifford/ACCESSIBILITY.md This skill is derived from that file. When in doubt, the example is authoritative.

Apply these rules whenever implementing or reviewing colour theme support in HTML, CSS, or JavaScript. Only load this skill if the project supports light/dark mode or user theme switching.

Critical Rule: Focus Is Navigation, Not Selection

A theme must not change until the user explicitly activates an option.

Moving keyboard focus or pointer hover across theme choices MUST NOT preview, select, or apply a theme. Tabbing across System, Light, and Dark MUST leave the page colours unchanged until the user presses Enter or Space.