Frontend & Design

CSS Modules Scoping

Write locally-scoped CSS with CSS Modules, preventing style collisions without runtime overhead or naming conventions.

Claude Code Cursor Copilot Windsurf Gemini CLI

Overview

CSS Modules automatically scope CSS class names to the component that imports them, preventing style collisions without BEM naming conventions or runtime CSS-in-JS overhead. AI agents can create `.module.css` files with locally-scoped styles and generate the corresponding component imports.

Every class in a CSS Module is hashed at build time, producing unique class names like `_button_1a2b3` in production. Your AI agent can write clean, semantic CSS class names without worrying about global conflicts, compose styles using `composes` for reuse, and implement global overrides with `:global()` when needed.

CSS Modules are natively supported by Vite, Next.js, Create React App, and most bundlers. AI agents can help you migrate from global CSS to CSS Modules incrementally, set up TypeScript declarations for type-safe imports, and organize styles alongside their components for better maintainability.

Who Is This For?

Teams wanting scoped CSS without adopting CSS-in-JS runtime overhead
Developers working on large codebases with style collision risks
Engineers implementing component-level styling in Vite or Next.js projects
Teams migrating from global CSS to component-scoped styles incrementally

Installation

Setup for Claude Code

CSS Modules work out of the box with Vite, Next.js, and most bundlers

Configuration

/* Button.module.css */
.button {
  padding: 0.5rem 1rem;
  border-radius: 0.375rem;
  font-weight: 600;
}
.primary { composes: button; background: #6366f1; color: white; }
.secondary { composes: button; background: #e2e8f0; color: #1e293b; }

// Button.tsx
import styles from "./Button.module.css";
<button className={styles.primary}>Click me</button>