{% set _up_mode = request.headers.get('X-Up-Mode', '') %}
{% if _up_mode == 'modal' %}
{# Still a <main>: this fragment replaces #main-content in the host document,
   so degrading it to a <div> would delete the main landmark from the page on
   the first modal navigation. #}
<main id="main-content" up-main class="fcu-modal-container">
    <div>
        {# Body first, as in base_full.html: a page may place flashes() itself. #}
        {% set _fcu_body %}
        {% block page_heading %}
          <h1 class="fcu-sr-only">{{ construct.page_heading }}</h1>
        {% endblock %}
        {% block content %}{% endblock %}
        {% endset %}
        {{ flashes() }}
        {{ _fcu_body }}
    </div>
</main>
{% else %}
<main class="fcu-main-content" id="main-content" up-main>
    <div>
        {% set _fcu_body %}{{ self.page_heading() }}{{ self.content() }}{% endset %}
        {{ flashes() }}
        {{ _fcu_body }}
    </div>
</main>
{% endif %}