Improve UI for stacked nav-pills

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

app/assets/stylesheets/gitlab_bootstrap/nav.scss

@@ -15,18 +15,16 @@
     > li > a {
       border-left: 4px solid #EEE;
       padding: 12px;
+      color: #777;
     }
     > .active > a {
       border-color: $primary_color;
-      border-radius: 0;
-      background: #F1F1F1;
-      color: $style_color;
-      font-weight: bold;
-      text-shadow: 0 1px 1px #fff;
+      background: none;
+      color: #333;
+      font-weight: bolder;
     }
 
     &.nav-stacked-menu {
-      background: #FAFAFA;
       li > a {
         padding: 16px;
       }
@@ -36,6 +34,7 @@
   &.nav-pills-small {
     > li > a {
       padding: 8px 12px;
+      font-size: 12px;
     }
   }
 }