Use tabs cssClass definition instead of JS

modules/cms/assets/js/october.cmspage.js

@@ -209,10 +209,7 @@
 
         var $primaryCollapseIcon = $('<a href="javascript:;" class="tab-collapse-icon primary"><i class="icon-chevron-down"></i></a>'),
             $primaryPanel = $('.control-tabs.primary-tabs', data.pane),
-            $secondaryPanel = $('.control-tabs.secondary-tabs', data.pane),
-            $primaryTabContainer = $('.nav-tabs', $primaryPanel)
-
-        $primaryTabContainer.addClass('master-area')
+            $secondaryPanel = $('.control-tabs.secondary-tabs', data.pane)
 
         if ($primaryPanel.length > 0) {
             $secondaryPanel.append($primaryCollapseIcon);

modules/cms/classes/asset/fields.yaml

@@ -13,6 +13,9 @@ fields:
         path: content_toolbar
         cssClass: collapse-visible
 
+tabs:
+    cssClass: master-area
+
 secondaryTabs:
     stretch: true
     fields:

modules/cms/classes/content/fields.yaml

@@ -15,6 +15,9 @@ fields:
 
     components: Cms\FormWidgets\Components
 
+tabs:
+    cssClass: master-area
+
 secondaryTabs:
     stretch: true
     fields:

modules/cms/classes/layout/fields.yaml

@@ -20,6 +20,9 @@ fields:
 
     components: Cms\FormWidgets\Components
 
+tabs:
+    cssClass: master-area
+
 secondaryTabs:
     stretch: true
     fields:

modules/cms/classes/page/fields.yaml

@@ -26,6 +26,7 @@ fields:
     components: Cms\FormWidgets\Components
 
 tabs:
+    cssClass: master-area
     fields:
         fileName:
             tab: cms::lang.editor.settings

modules/cms/classes/partial/fields.yaml

@@ -20,6 +20,9 @@ fields:
 
     components: Cms\FormWidgets\Components
 
+tabs:
+    cssClass: master-area
+
 secondaryTabs:
     stretch: true
     fields: