How is this site removing specific CSS rules from a scope or element?

I like to make userScripts and userStyles for myself. I've begrudgingly dealt with Shadow DOM here before, and it's nothing but a pain in the ass. However, now I'm seeing a userStyle that I'm trying to apply being removed immediately as it's applied (using Stylus). What is the mechanism behind this? Other styles from the same style sheet are still being honored. The element still has the same root, and is still be matched by the rules's selector. What might be the way this is achieved? https://youtu.be/YgbOrfel604 (Chromium 124.0.6367.61 (Official Build) (64-bit)) submitted by /u/svArtist [link] [留言]