Side-by-side comparison

Locally scoped CSS class names by default; built into Vite, Next.js and most bundlers with zero runtime.

Utility-first CSS framework and today's dominant styling approach; v4 is CSS-first with a Rust engine.

Mature CSS preprocessor with variables, mixins and modules; still widely used in established codebases.

Plugin-based CSS transformer behind autoprefixing and many frameworks' build pipelines.