Styling React Using CSS

There are many ways to style React with CSS, this tutorial will take a closer look at three common ways:

• Inline styling
• CSS stylesheets
• CSS Modules

Inline Styling

To style an element with the inline style attribute, the value must be a JavaScript object:

Example:

Insert an object with the styling information:

const Header = () => {
  return (
    <>
      <h1 style={{color: "red"}}>Hello Style!</h1>
      <p>Add a little style!</p>
    </>
  );
}

Note: In JSX, JavaScript expressions are written inside curly braces, and since JavaScript objects also use curly braces, the styling in the example above is written inside two sets of curly braces {{}}.

camelCased Property Names

Since the inline CSS is written in a JavaScript object, properties with hyphen separators, like background-color, must be written with camel case syntax:

Example:

Use backgroundColor instead of background-color:

const Header = () => {
  return (
    <>
      <h1 style={{backgroundColor: "lightblue"}}>Hello Style!</h1>
      <p>Add a little style!</p>
    </>
  );
}

JavaScript Object

You can also create an object with styling information, and refer to it in the style attribute:

Example:

Create a style object named myStyle:

const Header = () => {

  const myStyle = {
    color: "white",
    backgroundColor: "DodgerBlue",
    padding: "10px",
    fontFamily: "Sans-Serif"
  };

  return (
    <>
      <h1 style={myStyle}>Hello Style!</h1>
      <p>Add a little style!</p>
    </>
  );
}

CSS Stylesheet

You can write your CSS styling in a separate file, just save the file with the .css file extension, and import it in your application.

App.css:

Create a new file called "App.css" and insert some CSS code in it:

body {
  background-color: #282c34;
  color: white;
  padding: 40px;
  font-family: Sans-Serif;
  text-align: center;
}

Note: You can call the file whatever you like, just remember the correct file extension.

Import the stylesheet in your application:

index.js:

import React from 'react';
import ReactDOM from 'react-dom/client';
import './App.css';

const Header = () => {
  return (
    <>
      <h1>Hello Style!</h1>
      <p>Add a little style!.</p>
    </>
  );
}

const root = ReactDOM.createRoot(document.getElementById('root'));
root.render(<Header />);

CSS Modules

Another way of adding styles to your application is to use CSS Modules.

CSS Modules are convenient for components that are placed in separate files.

The CSS inside a module is available only for the component that imported it, and you do not have to worry about name conflicts.

Create the CSS module with the .module.css extension, example: my-style.module.css.

Create a new file called "my-style.module.css" and insert some CSS code in it:

my-style.module.css:

.bigblue {
  color: DodgerBlue;
  padding: 40px;
  font-family: Sans-Serif;
  text-align: center;
}

Import the stylesheet in your component:

Car.js:

import styles from './my-style.module.css'; 

const Car = () => {
  return <h1 className={styles.bigblue}>Hello Car!</h1>;
}

export default Car;

Import the component in your application:

index.js:

import ReactDOM from 'react-dom/client';
import Car from './Car.js';

const root = ReactDOM.createRoot(document.getElementById('root'));
root.render(<Car />);