Improve Charcoal theme

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

app/assets/stylesheets/themes/ui_modern.scss

@@ -27,6 +27,12 @@
           background: #234;
           border-left: 1px solid #456;
         }
+        .nav > li > a {
+          color: #89A;
+        }
+        .search-input {
+          border-color: #89A;
+        }
       }
     }
   }