Tailwind CSS v4 — What Changed and Why It Matters

Tailwind CSS v4 is a complete rewrite powered by a new high-performance engine called Oxide. It is dramatically faster and ships with a new CSS-first configuration system.

Key Changes

CSS-First Config

@import "tailwindcss";

@theme {
  --color-primary: #3DDB87;
  --font-sans: "Space Grotesk", sans-serif;
}

This is a massive improvement in developer experience.