site/_layouts/center.html
<!DOCTYPE html>
<html>
{% include head.html %}
<body>
<div class="site-wrap center">
{% include header.html %}
<div class="post p2 p-responsive wrap" role="main">
<div class="measure">
{{ content }}
</div>
</div>
</div>
{% include footer.html %}
</body>
</html>