Astroturf is a zero‑runtime CSS‑in‑JS tool that lets developers write styles inside JavaScript (or TypeScript) files using template literals, but then extracts those styles to static CSS files that can be processed with any existing pipeline such as Sass, PostCSS, or Less. It targets front‑end engineers who want the developer‑experience benefits of CSS‑in‑JS (co‑locating styles with components) without the runtime overhead or framework‑specific constraints.