@Norm I recall a few months ago there was some discussion about adding this functionality in the then “future”.
To recap the requirement, I find there is a missing feature which is the ability to add CSS code to the Class Editor. Currently this has to be done in a separate CSS file that has to be created, and loaded as Project Attachment in Project Settings. This works fine except that the code isn’t loaded in Edit mode and the affect of the CSS can only be seen in Preview mode. Then if you want to make a change to that code, the original file must be edited and reloaded.
If this could all be done via the Class Editor, such as using a new tab with a code entry box, it would be a big new feature.