layouts/404.html

{{ define "main" -}}
<div class="td-content">
  <h1>Not found</h1>
  <p>Oops! This page doesn't exist. Try going back to the <a href="{{ "" | relURL }}">home page</a>.</p>
  <p>You can learn how to make a 404 page like this in <a href="https://gohugo.io/templates/404/">Custom 404 Pages</a>.</p>
</div>
{{- end }}