Question

I'm trying to find a way to style scrollbars globally in my (also external) web components. Is there maybe a hook or way to inject a style in all used webcomponents or another construct or smart solution? In my owned web components I could fix it with a base class or mixin, but this doesn't apply to external components. The question is also whether is smart to style scrollbars in external components as those components could be designed and tested for a default scrollbar? Thanks in advance!