{#- Tarn: copy of Zensical's partials/tabs-item.html with Tarn navigation
    attributes supplied by partials/tarn.html. Source: https://raw.githubusercontent.com/zensical/ui/v0.0.39/dist/partials/tabs-item.html
    (UI v0.0.39 = Zensical 0.0.73). After a Zensical upgrade, review these calls and run scripts/check_upstream.py. -#}
{% import "partials/tarn.html" as tarn with context %}
{% macro render_content(nav_item, ref) %}
  {% set ref = ref or nav_item %}
  {{ ref.title or nav_item.title }}
{% endmacro %}
{% macro render(nav_item, ref) %}
  {% set ref = ref or nav_item %}
  {% set class = "md-tabs__item" %}
  {% if ref.active %}
    {% set class = class ~ " md-tabs__item--active" %}
  {% endif %}
  {% if nav_item.children %}
    {% set _ = namespace(index = none) %}
      {% if "navigation.indexes" in features %}
      {% for item in nav_item.children %}
        {% if item.is_index and _.index is none %}
          {% set _.index = item %}
        {% endif %}
      {% endfor %}
    {% endif %}
    {% set index = _.index %}
    {% set first = index or nav_item.children | first %}
    {% if first.children %}
      {{ render(first, ref) }}
    {% else %}
      <li class="{{ class }}" {{ tarn.navigation_attributes(first) }}>
        <a href="{{ first.url | url }}" class="md-tabs__link">
          {{ render_content(first, ref) }}
        </a>
      </li>
    {% endif %}
  {% else %}
    <li class="{{ class }}" {{ tarn.navigation_attributes(nav_item) }}>
      <a href="{{ nav_item.url | url }}" class="md-tabs__link">
        {{ render_content(nav_item) }}
      </a>
    </li>
  {% endif %}
{% endmacro %}