adjust .navbar-editor styles

src/client/styles/agile-admin/inverse/colors/_apply-colors.scss

@@ -309,6 +309,7 @@ body.on-edit {
     .page-editor-editor-container {
       border-right-color: $navbar-border;
       .navbar-editor {
+        border-bottom-color: $border;
         background-color: $active-nav-tabs-bgcolor;   // same color with active tab
       }
     }

src/client/styles/scss/_on-edit.scss

@@ -166,6 +166,10 @@ body.on-edit {
         }
       }
 
+      .navbar-editor {
+        border-bottom: 1px solid transparent;
+      }
+
       // add icon on cursor
       .autoformat-markdown-table-activated .CodeMirror-cursor {
         &:after {