{% set navPages = collections.all | eleventyNavigation %}

{% macro renderNavListItem(entry) %}
  {% if entry.children.length %}
    <li>
      <details
        {%- for child in entry.children %}
          {% if child.url == page.url %}
            class="is-active"
            open
          {% endif %}
        {% endfor %}
      >
        <summary>{{ entry.title }}</summary>
        <ul role="list">
          {%- for child in entry.children %}{{ renderNavListItem(child) }}{% endfor -%}
        </ul>
      </details>
    </li>
  {% else %}
    <li>
      <a href="{{ entry.url }}"
        {% if entry.url == page.url %}aria-current="page" {% endif %}>
        {{ entry.title }}
      </a>
    </li>
  {%- endif -%}
{%- endmacro %}

<ul class="nav-list" role="list">
{%- for entry in navPages %}{{ renderNavListItem(entry) }}{%- endfor -%}
</ul>