gatsby-theme-sputnik/src/components/layout.jsx

import React from "react";
import PropTypes from "prop-types";
import { useStaticQuery, graphql } from "gatsby";
import { Helmet } from "react-helmet";

import "modern-normalize";
import "typeface-lato";
import "./layout.css";

const Layout = ({ children }) => {
  const data = useStaticQuery(graphql`
    query SiteTitleQuery {
      site {
        siteMetadata {
          title
        }
      }
    }
  `);

  return (
    <>
      <Helmet>
        <html lang="en" />
        <title>{data.site.siteMetadata.title}</title>
      </Helmet>
      <main>{children}</main>
    </>
  );
};

Layout.propTypes = {
  children: PropTypes.node.isRequired
};

export default Layout;