<header class=“site-header shadow shadow-hover”>

{%- assign default_paths = site.pages | map: "path" -%}
{%- assign page_paths = site.header_pages | default: default_paths -%}
{%- assign titles_size = site.pages | map: 'title' | join: '' | size -%}
<nav class="border split-nav">  <!-- add 'fixed' to 'nav' => fix the nav to the top of page -->
  <div class="nav-brand" style="max-width: 75%;">
    <h4><a href="{{ "/" | relative_url }}">{{ site.title | escape }}</a></h4>
  </div>
  <div class="collapsible">
    {%- if titles_size > 0 -%}
    <input id="collapsible1" type="checkbox" name="collapsible1">
    <!-- mobile responsive hamburger menu start -->
    <button> 
      <label for="collapsible1">
        <div class="bar1"></div>
        <div class="bar2"></div>
        <div class="bar3"></div>
      </label>
    </button>
    <!-- mobile responsive hamburger menu end -->
    <div class="collapsible-body">
      <ul class="inline">
        {%- for path in page_paths -%}
          {%- assign my_page = site.pages | where: "path", path | first -%}
          {%- if my_page.title -%}
          <li><a href="{{ my_page.url | relative_url }}">{{ my_page.title | escape }}</a></li>
          {%- endif -%}
        {%- endfor -%}
      </ul>
    </div>
    {%- endif -%}
  </div>
</nav>

</header>