gcg-website/layouts/partials/filter-controls.html

<div class="row gta-cat">
  <div class="col-lg-12">
    <ul class="list-inline text-center filter-controls mb-5">
      <li class="list-inline-item m-3 text-uppercase active" data-filter="all">Alle</li>
      {{ $categories := slice }}
      {{ range .Data.Pages }}
        {{ $categories = $categories | append .Params.category }}
      {{ end }}
      {{ range ( $categories | uniq ) }}
        <li class="list-inline-item m-3 text-uppercase" data-filter="{{ . | urlize }}">{{ . | humanize }}</li>
      {{ end }}
    </ul>
  </div>
</div>
<noscript>
  <style>
    .gta-cat {
      display: none;
    }
  </style>
</noscript>