How to set style for pseudo elements (:after and :before)

Do you mean during the editing? Do you see it good if you deselect the component?

Yes during the editing. My idea was to implement the pseudo elements. When you select component to select state like hover, but to be :after or :before. The problem is that I need to set content: '' in the css rule and all the styles are applied on the main element.

Ok but is it correct once you deselect the component?