import Head from 'next/head';

export default () =>
  <header>
    <Head>
      <style>{`
        body {
          font-family: "Helvetica Neue", Arial, sans-serif;
        }
      `}</style>
    </Head>
  </header>;

import Head from 'next/head';

export default () =>
  <header>
    <Head>
      <style global jsx>{`
        body {
          font-family: "Helvetica Neue", Arial, sans-serif;
        }
      `}</style>
    </Head>
  </header>;

Fix flash of unstyled text
Fix flash of unstyled text