add navbar on 404 page

src/pages/404.tsx

@@ -2,15 +2,18 @@ import React from "react";
 import { NextPage } from "next";
 import Head from "next/head";
 import styled from "styled-components";
+import Header from "@components/Header";
 
 const NotFound = styled.main`
+  flex: 1 0 auto;
+  display: flex;
+  justify-content: center;
+  align-items: center;
+  p {
     text-align: center;
     font-size: 4rem;
     font-weight: 200;
-  position: absolute;
-  height: 10rem;
-  top: calc(50vh - 5rem);
-  width: 100%;
+  }
 `;
 
 const NotFoundPage: NextPage = () => (
@@ -19,8 +22,11 @@ const NotFoundPage: NextPage = () => (
       <title>404 | Ei vaan löydy</title>
       <meta name="robots" content="noindex" />
     </Head>
+    <Header />
     <NotFound id="not-found">
-      <strong>404</strong> | Ei vaan löydy
+      <p>
+        <strong>404</strong> | Ei&nbsp;vaan&nbsp;löydy
+      </p>
     </NotFound>
   </>
 );