Can you add a class to the body tag in CM1?
You can’t modify the properties of the body tag directly in CM1. There is a wrapping div immediately under the body tag that encompasses any elements on the page. You have control over this element in CM1 to add an ID and classes. This topmost element cannot be removed so it may server for your purposes.
For modifying the body element, however, you would need a script, as there is no access to the body tag.