hextra/layouts/shortcodes/tab.html

{{- $defaultIndex := int ((.Parent.Get "defaultIndex") | default "0") -}}

<div
  class="hextra-tabs-panel hx-rounded hx-pt-6 hx-hidden data-[state=selected]:hx-block"
  id="tabs-panel-{{ .Ordinal }}"
  role="tabpanel"
  {{- if eq .Ordinal $defaultIndex }} tabindex="0" {{ end -}}
  {{- if eq .Ordinal $defaultIndex }} data-state="selected" {{ end -}}
>
  {{- .InnerDeindent | markdownify -}}
</div>
{{- /* Drop trailing newlines */ -}}