documentation/docs/react/css.md
---
id: css
title: Built-in CSS Support
sidebar_label: Built-in CSS
description: How to use CSS in React?
---
React allows you to import CSS files from a JavaScript file.
For example, to add Global Stylesheet to boilerplate, we import following CSS file within `src/App.tsx`.
```css title="src/styles/global.css"
hmtl,
body {
margin: 0;
padding: 0;
font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans",
"Liberation Sans", sans-serif, "Apple Color Emoji", "Segoe UI Emoji", "Segoe UI Symbol", "Noto Color Emoji";
}
```
Then, import the `styles.css` file.
```tsx title="src/App.tsx"
import Home from "pages";
import "styles/global.css";
function App(): JSX.Element {
return (
<div className="App">
<Home />
</div>
);
}
export default App;
```
These styles will apply to all pages and components in your application.
### CSS Modules
[CSS Modules](https://github.com/css-modules/css-modules) let you use the same CSS class name in different files without worrying about naming clashes.
To style your components using CSS Modules, name your stylesheet files with the `[name].module.css`.
For example, lets check out a reusable Header component implementation.
```css title="components/header/index.module.css"
.header {
background-color: #20232A;
text-align: center;
}
```
```tsx title="components/header"
import React from "react";
import styles from "./index.module.css";
import { Logo } from "components";
export const Header: React.FC = () => {
return (
<div className={styles.header}>
<Logo />
</div>
);
};
```
<br/>
:::note
The class names which will be processed into a globally unique class name during build.
:::