text: import Link from 'next/link'
  
  export default ({ pathname }) => (
    <header>
      <Link prefetch href='/'>
        <a className={pathname === '/' && 'is-active'}>Home</a>
      </Link>
  
      <Link prefetch href='/about'>
        <a className={pathname === '/about' && 'is-active'}>About</a>
      </Link>
  
      <style jsx>{`
        header {
          margin-bottom: 25px;
        }
        a {
          font-size: 14px;
          margin-right: 15px;
          text-decoration: none;
        }
        .is-active {
          text-decoration: underline;
        }
      `}</style>
    </header>
  )
  