Zero-Runtime CSS From JS With Linaria

Linaria is a zero-runtime CSS-in-JS library that extracts CSS to plain files at build time using a Babel preset. Unlike traditional CSS-in-JS libraries (styled-components, Emotion), it has no runtime cost — no CSS parser is bundled with JavaScript, enabling parallel downloading of CSS and JS. It supports tagged template literal syntax, build-time JavaScript expressions, Sass-like nesting, SSR critical CSS extraction, and Webpack hot reload. The key trade-off is that dynamic values like props cannot be used since all CSS must be evaluable at build time.