views/four-oh-four.hbs
{{> layout_start_document}}
<link rel="stylesheet" href="/public/css/four-oh-four.css">
{{> layout_start_body}}
<main class="four-oh-four">
<header>
<h1>404</h1>
</header>
<section class="content-controls">
{{> back_button}}
</section>
<section>
<p>Oops, that page doesn't seem to exist.</p>
<p><a href="/">front page</a></p>
</section>
</main>
{{> layout_end}}