{# Reusable flash-message rendering, shared by every layout. #}
{% macro render_flashes() %}
  {% with messages = get_flashed_messages(with_categories=true) %}
    {% if messages %}
      <div class="flash-stack">
        {% for category, message in messages %}
          {% set cat = category if category != 'message' else 'info' %}
          <div class="alert alert-{{ cat }} alert-dismissible fade show d-flex align-items-center" role="alert">
            <span class="flash-icon">
              {%- if cat == 'success' %}<i class="bi bi-check-circle-fill"></i>
              {%- elif cat == 'danger' or cat == 'warning' %}<i class="bi bi-exclamation-triangle-fill"></i>
              {%- else %}<i class="bi bi-info-circle-fill"></i>{% endif -%}
            </span>
            <div class="flash-body">{{ message }}</div>
            <button type="button" class="btn-close ms-auto" data-bs-dismiss="alert" aria-label="Close"></button>
          </div>
        {% endfor %}
      </div>
    {% endif %}
  {% endwith %}
{% endmacro %}