BUG: Deleting a component without deleting its corresponding style, will adding new components later cause style conflicts?

Yes , you are right, I copying all matched styles ,so I can paste anywhere , even cross-browser paste, I find this to be extremely useful. When I delete a component, it does not remove the corresponding styles. This is a major issue， And when I copy and paste multiple times on the same website, it leads to a lot of redundant styles and easily causes style conflicts. so I can't simply expect those styles to be deleted. If possible, I would appreciate some suggestions.

If you're copying all matched styles it would also contain styles used by other elements so you can't simply expect those styles to be deleted.

it‘s still a problem

I don't see how this is a core bug. You're using your own copy/paste logic and it doesn't even seem correct, you should take care of the unique ids of each component/rule.

After deleting these child components, their styles still remain.

If you're copying all matched styles it would also contain styles used by other elements so you can't simply expect those styles to be deleted.

Please, if you're submitting a bug, ALWAYS provide a reproducible demo.