github.io/layouts/partials/menu.html

{{ $currentPage := . }}
{{ if .HasChildren }}
<li class='{{ if $currentPage.HasMenuCurrent "main" . }}active{{ end }}'>
  <a href='#'>{{ .Pre }}<span>{{ .Name }}</span></a>
</li>
<li>
  <ul class='sub-menu'>
    {{ range .Children }}
    <li class='{{ if $currentPage.IsMenuCurrent "main" . }}active{{ end }}'>
      <a href='{{ .URL }}'>{{ .Name }}</a>
    </li>
    {{ end }}
  </ul>
</li>
{{ else }}
<li>
  <a href='{{ .URL }}'>
    {{ .Pre }}
    <span>{{ .Name }}</span>
  </a>
</li>
{{ end }}