{#- Top-level navigation item in the Webis header. -#}
{% macro render(nav_item, ref) %}
  {% set ref = ref or nav_item %}
  {% set class = "webis-header__nav-item" %}
  {% if ref.active %}
    {% set class = class ~ " webis-header__nav-item--active" %}
  {% endif %}
  {% if nav_item.children %}
    {% set first = nav_item.children | first %}
    {% if first.children %}
      {{ render(first, ref) }}
    {% else %}
      <li class="{{ class }}">
        <a href="{{ first.url | url }}" class="webis-header__nav-link">{{ ref.title }}</a>
      </li>
    {% endif %}
  {% else %}
    <li class="{{ class }}">
      <a href="{{ nav_item.url | url }}" class="webis-header__nav-link">{{ ref.title }}</a>
    </li>
  {% endif %}
{% endmacro %}