text: import * as React from 'react';
  import ReactDOM from 'react-dom';
  import { styled } from 'linaria/react';
  
  import constants from './constants';
  
  const Title = styled.h1`
    font-family: ${constants.fontFamily};
    font-size: 16px;
    color: ${() => constants.primaryColor};
  `;
  
  function App() {
    return <Title>Hello world</Title>;
  }
  
  ReactDOM.render(<App />, document.getElementById('root'));
  