This gets you up to speed on Tailwind v4's CSS-first config approach using @theme directives instead of tailwind.config.js files. You'll want this when migrating from v3 or starting fresh with the new @tailwindcss/vite plugin. The big shift is defining design tokens directly in CSS with OKLCH colors and understanding the three @theme modes: default for CSS variables, inline for direct value substitution, and reference for fallbacks. Honestly, the inline mode is a nice performance win for static values, but the real win is just keeping your theme config in the same file as your styles. Includes concrete examples for two-tier variable systems, custom fonts, and animation keyframes.
npx skills add https://github.com/existential-birds/beagle --skill tailwind-v4