layouts/404.html

{{ define "main" }}
<div class="section">
  <div class="container">
  <h1 class="small-title medium-margin">404</h1>
  <h2 class="small-margin">Page not found :(</h2>
  <p>ProTip: Make sure you don't have a trailing slash in the URL</p>
  </div>
</div>
{{ end }}