hugo-theme-hilfe/layouts/shortcodes/expand.html

{{ $id := substr (sha1 .Inner) 0 8 }}
<div class="gdoc-expand">
  <label class="gdoc-expand__head flex justify-between" for="{{ $id }}-{{ .Ordinal }}">
    <span>{{ default "Expand" (.Get 0) }}</span>
    <span>{{ default "↕" (.Get 1) }}</span>
  </label>
  <input id="{{ $id }}-{{ .Ordinal }}" type="checkbox" class="gdoc-expand__control hidden" />
  <div class="gdoc-markdown--nested gdoc-expand__content">
    {{ .Inner | $.Page.RenderString }}
  </div>
</div>