website/themes/nluug/layouts/partials/header.html

<header class="header">
  <input class="side-menu" type="checkbox" id="side-menu">
  <label class="hamb" for="side-menu"><span class="hamb-line"></span></label>
  <nav class="nav">
        <ul class="menu">
          {{ $currentPage := . }}
          {{ range .Site.Menus.main }}
              {{ if .Children }}
                <li class="subnav">
                  <a href="{{ .URL }}">{{ .Name }}</a>
                  <ul class="subnav-content">
                    {{ range .Children }}
                      <li><a href="{{ .URL }}">{{ .Name }}</a></li>
                    {{ end }}
                  </ul>
                </li>
            {{ else }}
              <li class="{{ if $currentPage.HasMenuCurrent "main" . }}active{{ end }}"><a href="{{ .URL }}">{{ .Name }}</a></li>
            {{ end }}
          {{ end }}
        </ul>
  </nav>
</header>