Reduced num of nesting

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

@@ -4,29 +4,26 @@
     margin-left: 10px;
   }
 
-  .grw-pagetree-item-wrapper {
-    .grw-pagetree-item {
-      &:hover {
-        opacity: 0.7;
-      }
+  .grw-pagetree-item {
+    &:hover {
+      opacity: 0.7;
+    }
 
-      .grw-pagetree-button {
-        background-color: transparent;
+    .grw-pagetree-button {
+      background-color: transparent;
 
-        &.rotate {
-          transform: rotate(90deg);
-        }
+      &.rotate {
+        transform: rotate(90deg);
       }
+    }
 
-      .grw-pagetree-title {
-        margin: auto;
-        font-size: medium;
-      }
+    .grw-pagetree-title {
+      font-size: medium;
+    }
 
-      .grw-pagetree-control {
-        &:hover {
-          display: inline-block;
-        }
+    .grw-pagetree-control {
+      &:hover {
+        display: inline-block;
       }
     }
   }