computer-playbook/sphinx/templates/structure.html

{% macro render_headings(headings, level=1) %}
  <ul class="toctree-l{{ level }}">
  {% for item in headings %}
    <li class="toctree-l{{ level }}{% if item.current %} current{% endif %}"
        {% if item.children %} x-data="{ expanded: false }" {% endif %}>
      <a class="reference internal{% if item.children %} expandable{% endif %}"
         href="{{ pathto(item.link).replace('#', '') }}{% if item.anchor %}#{{ item.anchor }}{% endif %}"
         {% if item.children %}
           @click.prevent="expanded = !expanded"
           :class="{ 'expanded': expanded }"
         {% endif %}>
         {{ item.text }}
         {% if item.children %}
           <button @click.prevent.stop="expanded = !expanded" type="button" class="toggle-button" style="background: none; border: none; padding: 0; margin-left: 5px;">
             <span x-show="!expanded">
              <svg fill="currentColor" height="18px" stroke="none" viewBox="0 0 24 24" width="18px" xmlns="http://www.w3.org/2000/svg">
                <path d="M10 6L8.59 7.41 13.17 12l-4.58 4.59L10 18l6-6z"></path>
              </svg>
             </span>
             <span x-show="expanded">&#9660;</span>
           </button>
         {% endif %}
      </a>
      {% if item.children %}
        <div x-show="expanded">
          {{ render_headings(item.children, level+1) }}
        </div>
      {% endif %}
    </li>
  {% endfor %}
  </ul>
{% endmacro %}

{% if local_md_headings or local_subfolders %}
<div class="local-md-headings">
  <h3 class="toctree-l1">Index</h3>
  {% if local_md_headings %}
    {{ render_headings(local_md_headings) }}
  {% endif %}
  {% if local_subfolders %}
    {{ render_headings(local_subfolders) }}
  {% endif %}
</div>
{% endif %}