hugo-theme-introduction/layouts/partials/nav-single.html

<hr>
<nav class="nav nav-center">
    <span id="nav-toggle" class="nav-toggle"  onclick="document.getElementById('nav-menu').classList.toggle('is-active');">
      <span></span>
      <span></span>
      <span></span>
    </span>
    <div id="nav-menu" class="nav-left nav-menu">
      <span class="nav-item">
        <a href="{{ "/" | relURL }}">Main</a>
      </span>
      <span class="nav-item">
        <a href="{{ "/about" | relURL }}">About</a>
      </span>
      {{ if .Site.Params.showProjects }}
      <span class="nav-item">
        {{ if ne .Section "projects" }}
        <a href="{{ "/projects" | relURL }}">Projects</a>
        {{ else }}
        <a href="{{ "/projects" | relURL }}">Back to Projects</a>
        {{ end }}
      </span>
      {{ end }}
      {{ if .Site.Params.showBlog }}
      <span class="nav-item">
        {{ if ne .Section "blog" }}
        <a href="{{ "/blog" | relURL }}">Blog</a>
        {{ else }}
        <a href="{{ "/blog" | relURL }}">Back to Blog</a>
        {{ end }}
      </span>
      {{ end }}
      <span class="nav-item">
        <a href="{{ "/contact" | relURL }}">Contact</a>
      </span>
    {{ if .Site.RSSLink }}
      <span class="nav-item">
        <a href="{{ .Site.RSSLink }}"><i class="fa fa-rss"></i></a>
      </span>
    {{ end }}
    </div>
</nav>
<hr>