diff --git a/resources/skins.minerva.base.styles/common.less b/resources/skins.minerva.base.styles/common.less
index 53365f3..b52a6ab 100644
--- a/resources/skins.minerva.base.styles/common.less
+++ b/resources/skins.minerva.base.styles/common.less
@@ -78,8 +78,16 @@ textarea {
 	display: none !important;
 }
 
+#mw-mf-viewport {
+	position: relative;
+	height: 100%;
+}
+
 // We need to ensure the content has the chrome background - otherwise it will
 // overlap the menu during the main menu reveal/hide animation
 #mw-mf-page-center {
+	width: 100%;
+	position: relative;
 	background-color: @chromeColor;
+	z-index: @z-indexBase;
 }
diff --git a/resources/skins.minerva.mainMenu.styles/mainmenu.less b/resources/skins.minerva.mainMenu.styles/mainmenu.less
index ce89175..4610374 100644
--- a/resources/skins.minerva.mainMenu.styles/mainmenu.less
+++ b/resources/skins.minerva.mainMenu.styles/mainmenu.less
@@ -11,16 +11,6 @@
 @menuItemFontSize: 0.875em;
 @menuItemBackgroundColor: @skinContentBgColor;
 
-#mw-mf-viewport {
-	position: relative;
-	height: 100%;
-}
-
-#mw-mf-page-center {
-	width: 100%;
-	position: relative;
-}
-
 // needs to be more specific than .overlay rules
 .notifications-overlay.navigation-drawer {
 	right: 0;