Emotion

import { css } from 'emotion';

const styles = {
  panel: {
    backgroundColor: '#00ffff',
    textAlign: 'center',
    width: '100%',
    padding: '20px',
    ':hover': {
      color: '#ffffff',
      cursor: 'pointer'
    },
    '@media (max-width: 700px)': {
      backgroundColor: '#ff0000'
    }
  }
};

class App extends Component {
  render() {
    return (
      <div className={css(styles.panel)}>
        React + Emotion rocks!
      </div>
    );
  }
}