tailwindcss

Tailwind CSS is a utility-first CSS framework that provides low-level utility classes for building custom designs without writing custom CSS. Instead of pre-designed components, Tailwind gives you classes like flex, pt-4, text-center, and bg-blue-500 that you compose directly in your HTML to build any design. The framework's configuration file (tailwind.config.js) allows complete customization of colors, spacing, typography, breakpoints, and every other design token. Tailwind uses a JIT (Just-in-Time) engine that generates only the CSS classes you actually use, keeping production bundles tiny regardless of how many utilities are available. The framework supports responsive design with breakpoint prefixes (md:flex), state variants (hover:bg-blue-700, focus:ring), dark mode (dark:bg-gray-900), and arbitrary values (w-[137px]) for one-off measurements. Tailwind's plugin system extends the framework with custom utilities, components, and variants. The framework has fundamentally changed how many developers write CSS, favoring colocation of styles with markup over separate stylesheet files. Tailwind CSS works with any JavaScript framework and is the most popular CSS framework in modern web development.