Resolve #3351298 "Dropdown"

Closes #3351298

css/sass/_responsive.scss

 @media (max-width: 500px) {
-  .search-box-content input[type="search"] {
+  .search-box-content input[type='search'] {
     padding: 15px;
   }
-  .search-box-content input[type="submit"] {
+  .search-box-content input[type='submit'] {
     padding: 10px 20px;
   }
   .align-left,
@@ -191,6 +191,7 @@
   .active-menu .menu-wrap .dropdown-arrow {
     position: absolute;
     right: 10px;
+    z-index: 100;
   }
   .active-menu ul.main-menu ul.submenu,
   .active-menu ul.menu ul.submenu {
@@ -199,11 +200,23 @@
     top: 0;
     opacity: 1;
   }
+  .active-menu ul.main-menu li.main-menu-item.expanded ul.submenu {
+    display: none;
+  }
+  .active-menu ul.main-menu li.main-menu-item.expanded.open ul.submenu {
+    display: block;
+  }
+  .active-menu
+    ul.main-menu
+    li.main-menu-item.expanded.open
+    .fa-angle-down:before {
+    content: '\f106';
+  }
   .active-menu ul.main-menu ul.submenu::before,
   .active-menu ul.main-menu ul.submenu::after,
   .active-menu ul.menu ul.submenu::before,
   .active-menu ul.menu ul.submenu::after {
-    content: "";
+    content: '';
     display: table;
     clear: both;
   }