diff --git a/src/project/templates/project/includes/main_menu.html b/src/project/templates/project/includes/main_menu.html
index a45435d..90a4c51 100644
--- a/src/project/templates/project/includes/main_menu.html
+++ b/src/project/templates/project/includes/main_menu.html
@@ -1,6 +1,8 @@
 {% load menu_tags thumbnail util_tags %}
 
-<div class="navigation__main">
+<div class="navigation__main" data-active="{% spaceless %}
+{% for child in children %}{% if child.selected or child.ancestor %}{{ forloop.counter0 }}{% endif %}{% endfor %}
+{% endspaceless %}">
     {% for n in 'nn' %}
         <div class="{% cycle 'navigation__images' 'navigation__list' %}">
             {% for child in children|slice:'3' %}