Fix little HTML mistakes

backend/templates/base_with_header.html

@@ -4,7 +4,7 @@
     <div class="header-container">
         {% include "title.html" %}
 
-        <span class="header-menu">
+        <div class="header-menu">
             {% include "search.html" %}
 
             <span class="user-menu">
@@ -43,7 +43,7 @@
                 {% endif %} >
                 <span class="slider"></span>
             </label>
-        </span>
+        </div>
     </div>
 
     <div class="main-container">