--- a/src/pyams_skin/interfaces/__init__.py	Thu May 27 14:15:54 2021 +0200
+++ b/src/pyams_skin/interfaces/__init__.py	Tue Jul 13 08:00:55 2021 +0200
@@ -78,6 +78,10 @@
     def get_skin(self, request=None):
         """Get skin matching this content"""
 
+    container_class = TextLine(title=_("Container class"),
+                               description=_("Main page container class"),
+                               required=False)
+
     custom_stylesheet = FileField(title=_("Custom stylesheet"),
                                   description=_("This custom stylesheet will be used to override selected theme styles"),
                                   required=False)