Tailwind CSS

Writes and debugs Tailwind CSS: utility classes, theme config, dark mode, variants, plugins, and build setup. Not for CSS mechanics themselves — stacking contexts, flex sizing, and cascade behavior belong to the `css` skill. Use when a class produces no CSS, when dynamically built names (`bg-${color}-500`) never render, when styles work in dev but vanish after deploy, when your own CSS beats a utility or can't override one, when `@apply` breaks inside a Vue, Svelte, or CSS-module file, when `hover:`, `group-hover:`, `peer-*`, `has-[…]`, or `dark:` won't fire, when upgrading v3 to v4 (`@tailwind` directives, `tailwind.config.js` → `@theme`, renamed utilities), when adding custom colors, spacing, breakpoints, fonts, or keyframes, when wiring Tailwind into Vite, Next.js, Astro, SvelteKit, Rails, or Laravel, when the CSS bundle is huge or rebuilds crawl, when Preflight flattens third-party widgets, or when choosing between `@apply`, a component, and `tailwind-merge`.