CSS Modules

// src/vite-env.d.ts or src/types/css-modules.d.ts
declare module '*.module.css' {
  const classes: { [key: string]: string }
  export default classes
}

npm install -D vite-plugin-css-modules-dts

// vite.config.ts
import { defineConfig } from 'vite'
import react from '@vitejs/plugin-react'
import cssModulesDts from 'vite-plugin-css-modules-dts'

export default defineConfig({
  plugins: [
    react(),
    cssModulesDts({
      // Generate .d.ts next to .module.css files
      outputDir: '.',
    })
  ]
})

// Button.module.css.d.ts (auto-generated)
declare const styles: {
  readonly button: string
  readonly primary: string
  readonly secondary: string
}
export default styles

npm install -D typed-css-modules

# Generate declarations
npx tcm src --pattern '**/*.module.css'

# Watch mode
npx tcm src --pattern '**/*.module.css' --watch

{
  "scripts": {
    "css:types": "tcm src --pattern '**/*.module.css'",
    "css:types:watch": "tcm src --pattern '**/*.module.css' --watch"
  }
}

/* Card.module.css */
.card {
  border-radius: 0.5rem;
  background: white;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
  overflow: hidden;
}

.header {
  padding: 1rem;
  border-bottom: 1px solid hsl(0, 0%, 90%);
}

.content {
  padding: 1.5rem;
}

.footer {
  padding: 1rem;
  background: hsl(0, 0%, 98%);
}

// Card.tsx
import styles from './Card.module.css'

export function Card({ children }: { children: React.ReactNode }) {
  return <div className={styles.card}>{children}</div>
}

Card.Header = ({ children }: { children: React.ReactNode }) => (
  <header className={styles.header}>{children}</header>
)

Card.Content = ({ children }: { children: React.ReactNode }) => (
  <div className={styles.content}>{children}</div>
)

Card.Footer = ({ children }: { children: React.ReactNode }) => (
  <footer className={styles.footer}>{children}</footer>
)

/* theme.css (global) */
:root {
  --color-primary: hsl(221, 83%, 53%);
  --color-primary-dark: hsl(224, 76%, 48%);
  --spacing-sm: 0.5rem;
  --spacing-md: 1rem;
}

/* Button.module.css */
.button {
  background-color: var(--color-primary);
  padding: var(--spacing-sm) var(--spacing-md);
}

.button:hover {
  background-color: var(--color-primary-dark);
}

/* theme.module.css */
.light {
  --bg: white;
  --text: hsl(0, 0%, 9%);
  --border: hsl(0, 0%, 90%);
}

.dark {
  --bg: hsl(0, 0%, 9%);
  --text: hsl(0, 0%, 98%);
  --border: hsl(0, 0%, 20%);
}

/* Component.module.css */
.component {
  background-color: var(--bg);
  color: var(--text);
  border: 1px solid var(--border);
}

/* Modal.module.css */
.overlay {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.5);
  opacity: 0;
  transition: opacity 200ms ease;
}

.overlayVisible {
  composes: overlay;
  opacity: 1;
}

.modal {
  position: fixed;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%) scale(0.95);
  opacity: 0;
  transition: all 200ms cubic-bezier(0.16, 1, 0.3, 1);
}

.modalVisible {
  composes: modal;
  transform: translate(-50%, -50%) scale(1);
  opacity: 1;
}

@keyframes slideIn {
  from {
    transform: translate(-50%, -50%) translateY(20px) scale(0.95);
    opacity: 0;
  }
  to {
    transform: translate(-50%, -50%) translateY(0) scale(1);
    opacity: 1;
  }
}

.modalAnimated {
  animation: slideIn 300ms cubic-bezier(0.16, 1, 0.3, 1);
}

import styles from './ComplexCard.module.css'

function ComplexCard({ title, children }: Props) {
  return (
    // Tailwind for layout, CSS Module for complex styles
    <div className={`${styles.card} p-4 md:p-6`}>
      <h2 className={`${styles.title} text-lg font-semibold mb-2`}>
        {title}
      </h2>
      <div className={styles.animatedContent}>
        {children}
      </div>
    </div>
  )
}

// vite.config.ts
export default defineConfig({
  build: {
    cssMinify: 'lightningcss',
    cssCodeSplit: true,  // Separate CSS per chunk
  }
})