Resolve "fix: readability on text button"

Closes #16 (closed)

common/common.scss

@@ -247,9 +247,11 @@ a {
 }
 
 .list-controls .combo-box .combo-box-header {
-  border: none;
+  border: 1px solid $primary-medium;
+  color: $primary;
+  box-shadow: 1px 1px 5px 1px rgba(67,66,66, .2);
   @include border-radius;
-  background-color: $header_background;
+  background-color: $header_primary;
 }
 
 .menu-panel .panel-body-bottom .btn {
@@ -366,7 +368,7 @@ a:hover {
 
 .admin-controls, .email-template, .admin-container {
   .nav-pills>li a.active {
-    background: var(--tertiary);
+    background: var(--primary-medium);
     color: var(--secondary);
   }
   .btn-primary {