_layouts/default.html (13 lines of code) (raw):
{% include top.html %}
<body class="wrap">
<header>
{% include header.html %}
</header>
<div class="container p-4 pt-5">
<main role="main" class="pb-5">
{{ content }}
</main>
{% include footer.html %}
</div>
</body>
</html>