How to add custom css class to Specifics resource

Hi, imagine i have UserResource and PostResource.
How to add custom css class to PostResource only?

My goals actually add custom class in Table Header but i ask AI or read documentation and is not possible, so maybe you can help how to add custom class css to Resource so i can nested class like .custom .fi-header { apply: px-12; }

Thank you

Solution

ah, it's not on the body, it's inside main.