VIewing/sharing existing per-site ("cosmetic") CSS rules?

I successfully used [ Brave -> Block Element Via Selector ] to block an annoying site design element. Now, I’d like to advise someone else, less versed in the ways of the DOM/CSS how to do exactly the same block rule.

Is there anyplace I can view the rule I set up?

Any way to share it as text for precise duplication?

Maybe get the user to copy/paste the rule you used? Probably the easiest way to do it

I’d love to do that - but where can I view the rule, in order to copy the text? (And where would I tell them to paste it?)