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designTailwind

Respect Color Scheme Preference

MUST

MUST: Apply dark class in inline <head> script before first paint to prevent theme flash

Initialize theme from prefers-color-scheme before page renders

Bad

Good

Why it matters

If you wait for JavaScript to run before checking the color scheme, users see a flash of the wrong theme (FART). Inline a script in <head> that runs synchronously before render.

References

Built by Gleb Stroganov, design engineer at Evil Martians.

The rules come from other people's skills and guidelines — Vercel, Rauno Freiberg, @Ibelick, impeccable, Emil Kowalski, Tailwind, RAMS — each one credited on the Sources page. The work here is extraction and wiring: every rule is pulled into one corpus, given a good and a bad example you can operate, a MUST/SHOULD/NEVER rule an agent can paste, and a link back to where it came from.