Also covers dark-mode variant setup, responsive breakpoints via @theme, CSS layer hierarchy (theme, base, components, utilities), and plugin integration — the full CSS-first replacement for tailwind.config.js.

Tailwind CSS Core v4.3

Overview

Tailwind CSS v4 (since v4.0; current stable v4.3) uses a CSS-first approach that eliminates the need for a traditional tailwind.config.js file. All configuration is now done directly in your CSS files via specialized directives.

Key Concepts

1. @import "tailwindcss"

Entry point to load Tailwind CSS. Place at the beginning of your main CSS file.