<header class=“site-header” role=“banner”>

<div class="wrapper">
  {%- assign default_paths = site.pages | map: "path" -%}
  {%- assign page_paths = site.header_pages | default: default_paths -%}

  {%- if page_paths -%}
    <nav class="site-nav">
      <a class="page-link" href="{{ site.baseurl }}{% link index.md %}">Portfolio</a>
      <a class="page-link" href="{{ site.baseurl }}{% link posts.md %}">Posts</a>
    </nav>
  {%- endif -%}
</div>

</header>