Navigation selects the current page

templates/nav.html

@@ -1,9 +1,9 @@
 <nav>
   <menu>
-    <li><a class="nav_selected" href="/">Home</a></li>
+    <li><a {% if section and section == root %} class="nav_current" {% endif %} href="/">Home</a></li>
     {% for subsection in root.subsections %}
     {% set subsection = get_section(path=subsection, metadata_only=true) %}
-    <li><a href="{{ subsection.permalink }}">{{ subsection.title }}</a></li>
+    <li><a href="{{ subsection.permalink }}" {% if section and section == subsection %} class="nav_current" {% endif %}>{{ subsection.title }}</a></li>
     {% endfor %}
   </menu>
 </nav>