vanilla-hugo/layouts/shortcodes/sidenote.html

<span class="sidenote">
<label class="sidenote-label" for="{{- .Get 1 -}}">{{- .Get 2 | markdownify -}}</label>
<input class="sidenote-checkbox" style="display: none;" type="checkbox" id="{{- .Get 1 -}}"></input>
{{- if $offset := .Get 3 -}}
<span class="sidenote-content sidenote-{{- .Get 0 -}}" style="margin-top: {{- $offset -}}rem">
{{- else -}}
<span class="sidenote-content sidenote-{{- .Get 0 -}}">
{{- end -}}
<span class="sidenote-delimiter">[{{- i18n "note" -}}:</span>
{{- .Inner -}}
<span class="sidenote-delimiter">]</span>
</span>
</span>