<div id="root" />
.simple {
  color: red;
}
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class SimpleComponent extends React.Component {
  render() {
    return (
      <div className="simple">
        <h1>Hello, React!</h1>
      </div>
    )
  }
}

React.render(<SimpleComponent />, document.getElementById('root'))
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External CSS

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External JavaScript

  1. https://cdnjs.cloudflare.com/ajax/libs/react/0.14.7/react.min.js