apply hierarchy more than level 10

packages/app/src/styles/_page-tree.scss

@@ -57,7 +57,7 @@ $grw-pagetree-item-padding-left: 10px;
     }
   }
 
-  // Set multiplied padding-left to each pagetree-item　to realize a hierarchical structure
+  // To realize a hierarchical structure, set multiplied padding-left to each pagetree-item
 
   > .grw-pagetree-item-container {
     > .grw-pagetree-item {
@@ -99,6 +99,9 @@ $grw-pagetree-item-padding-left: 10px;
                       > .grw-pagetree-item {
                         padding-left: $grw-pagetree-item-padding-left * 10;
                       }
+                      .grw-pagetree-item {
+                        padding-left: $grw-pagetree-item-padding-left * 10;
+                      }
                     }
                   }
                 }