How to protect a file from modification like Custom CSS?

RemNote Learning RemNote
#1

I just deleted some of my Custom CSS snippets by mistake and can not undo somehow. Is it possible to protect specific files from modification?

#2

Closest I can think of is to mark them as super private rems (command available in the list of / commands, just search for private)

#3

thank you but I think some pages should be protected…