{% macro render_toc(toc) %}
    <ul>
        {% for item in toc %}
            <li>
                <a href="{{ item.permalink | safe }}">{{ item.title }}</a>
                {% if item.children %}
                    {{ post::render_toc(toc=item.children) }}
                {% endif %}
            </li>
        {% endfor %}
    </ul>
{% endmacro %}