_layouts/default.html (14 lines of code) (raw):
<!DOCTYPE html>
<html lang="{{ page.lang | default: site.lang | default: "en" }}">
{% include head.html %}
<body>
{% include topnav.html %}
<div class="page-content">
<div class="wrapper">
{{ content }}
</div>
</div>
{% include footer.html %}
{% include js_files.html %}
</body>
</html>