React Base Fiddle (JSX)

Starting point for creating JSFiddles with React.

HTML

<script src="https://unpkg.com/react@16/umd/react.development.js"></script>
<script src="https://unpkg.com/react-dom@16/umd/react-dom.development.js"></script>
<script src="https://unpkg.com/[email protected]/dist/style-it-standalone.js"></script>
<div id="container">
    <!-- This element's contents will be replaced with your component. -->
</div>

Babel + JSX

class App extends React.Component {  
  render() {
    return (
      <div>
        <Style>
          {`
            body {
              font-size: small;
              font-family: arial;
            }
            h1 {
              font-size: large;
            }
            h2 {
              font-size: medium;
            }
            h3 {
              font-size: small;
            }
            a {
              color: blue;
            }
            a:hover {
              color: aqua;
            }
         `}
        </Style>

        <header>
        	<h1>Main Header</h1>
        </header>
        <main>
        	<h2>Secondary Header</h2>
          <p><a src="#">Test</a></p>
        </main>
        <footer>Copyright (c) My Company</footer>
      </div>
    );
  }
}

ReactDOM.render(
  <App />,
  document.getElementById('container')
);