{% comment %}
    Bootstrap 5 styles .btn-close, which draws its own icon and must therefore be
    empty. Its Bootstrap 4 twin is .close around a times the markup supplies -- the
    pair cannot be carried on one element, which is why it is a template per pack
    rather than two class names on one button.
{% endcomment %}
<button type="button" class="btn-close" aria-label="Close" data-bs-dismiss="modal"></button>