Tailwind CSS

Tailwind CSS ended the CSS architecture debate by making it someone else's problem. Utility classes directly in your HTML — flex items-center gap-4 — and a build step that strips unused styles to near-zero CSS output. You either get it immediately or you hate it. Most people who try it get it.

Bootstrap is the legacy component library (great for prototyping, bad for custom design). Vanilla CSS with custom properties is the purist approach. UnoCSS is the atomic CSS alternative that's faster and more flexible. Panda CSS offers type-safe CSS-in-JS.

If you're building a custom UI — SaaS dashboard, marketing site, web app — Tailwind is the fastest path from design to code. The JIT compiler is instant. Tailwind UI and Headless UI provide components when you need them. MIT licensed.

The catch: your HTML will look like alphabet soup. Long className strings with dozens of utilities are real code people ship. Some developers find this unreadable and unmaintainable. Also, Tailwind v4 changed enough that migration from v3 is non-trivial.