diff --git a/mkdocs/themes/readthedocs/base.html b/mkdocs/themes/readthedocs/base.html
index fe4c1474..b6b7ba65 100644
--- a/mkdocs/themes/readthedocs/base.html
+++ b/mkdocs/themes/readthedocs/base.html
@@ -57,7 +57,11 @@
       </div>
 
       <div class="wy-menu wy-menu-vertical" data-spy="affix" role="navigation" aria-label="main navigation">
-      {% include "toc.html" %}
+        <ul class="current">
+          {% for nav_item in nav %}
+            <li>{% include "toc.html" %}<li>
+          {% endfor %}
+        </ul>
       </div>
       &nbsp;
     </nav>
diff --git a/mkdocs/themes/readthedocs/css/theme_extra.css b/mkdocs/themes/readthedocs/css/theme_extra.css
index 675760c9..ccb384e9 100644
--- a/mkdocs/themes/readthedocs/css/theme_extra.css
+++ b/mkdocs/themes/readthedocs/css/theme_extra.css
@@ -25,7 +25,7 @@ h3, h4, h5, h6 {
     color: #838383;
 }
 
-.wy-menu-vertical .toctree-l2 a {
+.wy-menu-vertical .subnav a {
     padding: 0.4045em 2.427em;
 }
 
@@ -116,3 +116,11 @@ code.cs, code.c {
     padding: 6px 12px;
     border-color: #D1D4D5;
 }
+
+.wy-menu-vertical li ul {
+    display: inherit;
+}
+
+.wy-menu-vertical li ul.subnav ul.subnav{
+    padding-left: 1em;
+}
diff --git a/mkdocs/themes/readthedocs/toc.html b/mkdocs/themes/readthedocs/toc.html
index c7f1d03d..6cd2fc9b 100644
--- a/mkdocs/themes/readthedocs/toc.html
+++ b/mkdocs/themes/readthedocs/toc.html
@@ -1,38 +1,23 @@
-<ul class="current">
-    {% for nav_item in nav %}
-        {% if nav_item.children %}
-            <span>{{ nav_item.title }}</span>
-            {% for nav_item in nav_item.children %}
-                <li class="toctree-l2 {% if nav_item.active%}current{%endif%}">
-                    <a class="{% if nav_item.active%}current{%endif%}" href="{{ nav_item.url }}">{{ nav_item.title }}</a>
-                    {% if nav_item == current_page %}
-                        <ul>
-                        {% for toc_item in toc %}
-                            <li class="toctree-l3"><a href="{{ toc_item.url }}">{{ toc_item.title }}</a></li>
-                            {% for toc_item in toc_item.children %}
-                                <li><a class="toctree-l4" href="{{ toc_item.url }}">{{ toc_item.title }}</a></li>
-                            {% endfor %}
-                        {% endfor %}
-                        </ul>
-                    {% endif %}
-                </li>
+{% if nav_item.children %}
+    <ul class="subnav">
+    <li><span>{{ nav_item.title }}</span></li>
+
+        {% for nav_item in nav_item.children %}
+            {% include 'toc.html' %}
+        {% endfor %}
+    </ul>
+{% else %}
+    <li class="toctree-l1 {% if nav_item.active%}current{%endif%}">
+        <a class="{% if nav_item.active%}current{%endif%}" href="{{ nav_item.url }}">{{ nav_item.title }}</a>
+        {% if nav_item == current_page %}
+            <ul>
+            {% for toc_item in toc %}
+                <li class="toctree-l3"><a href="{{ toc_item.url }}">{{ toc_item.title }}</a></li>
+                {% for toc_item in toc_item.children %}
+                    <li><a class="toctree-l4" href="{{ toc_item.url }}">{{ toc_item.title }}</a></li>
+                {% endfor %}
             {% endfor %}
-        {% else %}
-            <li class="toctree-l1 {% if nav_item.active%}current{%endif%}">
-                <a class="{% if nav_item.active%}current{%endif%}" href="{{ nav_item.url }}">{{ nav_item.title }}</a>
-                {% if nav_item == current_page %}
-                    <ul>
-                    {% for toc_item in toc %}
-                        <li class="toctree-l3"><a href="{{ toc_item.url }}">{{ toc_item.title }}</a></li>
-                        {% for toc_item in toc_item.children %}
-                            <li><a class="toctree-l4" href="{{ toc_item.url }}">{{ toc_item.title }}</a></li>
-                        {% endfor %}
-                    {% endfor %}
-                    </ul>
-                {% endif %}
-            </li>
+            </ul>
         {% endif %}
-
-    {% endfor %}
-</ul>
-
+    </li>
+{% endif %}