Styling React Using CSS
There are many ways to style React with CSS, this tutorial will take a closer look at inline styling, and CSS stylesheet.
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:
class MyHeader extends React.Component {
  render() {
    return (
      <div>
      <h1 style={{color: "red"}}>Hello Style!</h1>
      <p>Add a little style!</p>
      </div>
    );
  }
}
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 two names, like background-color, 
must be written with camel case syntax:
Example:
Use backgroundColor instead of 
  background-color:
class MyHeader extends React.Component {
  render() {
    return (
      <div>
      <h1 style={{backgroundColor: "lightblue"}}>Hello Style!</h1>
      <p>Add a little style!</p>
      </div>
    );
  }
}
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:
class MyHeader extends React.Component {
  render() {
    const mystyle = {
      color: "white",
      backgroundColor: "DodgerBlue",
      padding: "10px",
      fontFamily: "Arial"
    };
    return (
      <div>
      <h1 style={mystyle}>Hello Style!</h1>
      <p>Add a little style!</p>
      </div>
    );
  }
}
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: Arial;
  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'; import './App.css'; class MyHeader extends React.Component { render() { return ( <div> <h1>Hello Style!</h1> <p>Add a little style!.</p> </div> );}}ReactDOM.render(<MyHeader />, document.getElementById('root'));
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 
extesion, example: mystyle.module.css.
mystyle.module.css:
Create a new file called "mystyle.module.css" and insert some CSS code in it:
.bigblue {
  color: DodgerBlue;
  padding: 40px;
  font-family: Arial;
  text-align: center;
}
Import the stylesheet in your component:
App.js:
import React from 'react';
import ReactDOM from 'react-dom';
import styles from './mystyle.module.css'; 
class Car extends React.Component {
  render() {
    return <h1 className={styles.bigblue}>Hello Car!</h1>;
  }
}
export default Car;
Import the component in your application:
index.js:
import React from 'react';
import ReactDOM from 'react-dom';
import Header from './App.js';
ReactDOM.render(<Car />, document.getElementById('root'));

