UnoCSS

UnoCSS is an on-demand Atomic CSS engine built for performance and flexibility. It operates without parsing, abstract syntax trees (AST), or file scanning, resulting in a development experience that is both fast and enjoyable. The core principle is to provide utility classes instantly, as you need them.

This approach offers several key advantages:

• Instant Speed: It is exceptionally fast, benchmarking at up to 5x faster than Windi CSS or Tailwind's JIT engine. This is achieved by its innovative on-demand architecture.
• Lightweight Core: With zero dependencies and a browser-friendly size of just ~6kb (minified + brotli), it adds minimal overhead to your project.
• Powerful and Customizable: The engine is not just fast but also highly configurable. You can use presets, transformers, and custom rules to create a design system that perfectly matches your requirements.