_includes/header.html
<!-- Fixed navbar -->
<div class="container">
<nav class="navbar navbar-expand-lg fixed-top navbar-dark bg-primary">
<a class="navbar-brand" href="{{ site.baseurl }}/">{{ site.title }}</a>
<button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbarSupportedContent" aria-controls="navbarSupportedContent" aria-expanded="false" aria-label="Toggle navigation"><span class="navbar-toggler-icon"></span>
</button>
<div class="collapse navbar-collapse" id="navbarSupportedContent">
<ul class="nav navbar-nav">
{% for my_page in site.pages %}{% if my_page.title %}<li class="nav-item"><a class="nav-link" href="{{ my_page.url | prepend: site.baseurl }}">{{ my_page.title }}</a></li>{% endif %}{% endfor %}
</ul>
</div>
</nav>
</div>
<div id="btop"></div>