Fixed z-index definitions to avoid hiding of tree menus

Change-Id: I71044f36ac9c195341dd38735cd8a4c45ee09a36
diff --git a/dev/scss/header/hint.scss b/dev/scss/header/hint.scss
index d5c6a4a..b2e9bee 100644
--- a/dev/scss/header/hint.scss
+++ b/dev/scss/header/hint.scss
@@ -60,7 +60,7 @@
   position: absolute;
   left: 0;
   top: 0;
-  z-index: 900;
+  z-index: 90;
   white-space: pre-wrap;
   height: 0;
   display: block;