{% load simple_page mptt_tags %}
<ul class="nav-level-1">
    {% if root %}
        <li{% if page.is_root_node %} class="active"{% endif %}>
            <a href="{{ root.get_absolute_url }}">{{ root.title }}</a>
        </li>
    {% endif %}
    {% recursetree nodes %}
        <li{% if page|is_active:node %} class="active"{% endif %}>
            <a href="{{ node.get_absolute_url }}">{{ node.title }}</a>
            {% if not node.is_leaf_node and not node|level > max_level%}
                <ul class="nav-level-{{ node|level }}">
                    {{ children }}
                </ul>
            {% endif %}
        </li>
    {% endrecursetree %}
</ul>