make there not be two scroll bars sometimes

src/css/units.css

@@ -5,3 +5,5 @@ $sprites-per-row: 5;
 $menu-bar-height: 3rem;
 $sprite-info-height: 5.25rem; /* @todo: SpriteInfo isn't explicitly set to this height yet */
 $stage-menu-height: 3rem;
+
+$library-header-height: 4.375rem;