JSFiddle - React, Tailwind, and code Playground

HTML

<script src="https://cdnjs.cloudflare.com/ajax/libs/react/0.14.7/react-dom.js"></script>
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/twitter-bootstrap/3.3.6/css/bootstrap.css">
<script src="https://npmcdn.com/classnames/index.js"></script>
<div class="js-app"></div>

CSS

* {
  -webkit-font-smoothing: antialiased;
}

body {
    padding: 5%;
}

Babel + JSX

console.clear();

const Input = React.createClass({
	getInitialState() {
    	return {
        	quantity: 0
        }
    },
    
    updateQuantity() {
    	  this.setState({
        	quantity: this.state.quantity + 1
        });
    },
    
    render() {
        return (
        	<div>
              <input type="text" value={this.state.quantity}/>
              <button onClick={this.updateQuantity}>Update</button>
          	</div>
    	)
    }
});
ReactDOM.render(<Input />, document.body.querySelector('.js-app'));