13 lines (12 with data), 610 Bytes

<div class="container-fluid" id="container">
  <div class="row">
    <div class="col-2 px-1 position-fixed vh-100 overflow-auto" id="toc">
      <h5 class="px-1">Table of contents</h5>
      <nav class="nav nav-pills flex-column lh-sm" id="toc-navbar">
        {% for title, dom_id, tags_ in titles|zip(dom_ids, tags) %}
        <a class="nav-link list-group-item list-group-item-action text-break" href="#{{ dom_id }}"
          data-mne-tags="{% for tag in tags_ %} {{ tag }} {% endfor %}">{{ title }}</a>
        {% endfor %}
      </nav>
    </div>
    <div id="content" class="accordion col-10 offset-2">