The new scrollbar styling properties are actually pretty consistent with native platforms. There's not that much flexibility with them - e.g. you can't define width in pixels, you just chose between thick, thin, or none, which match the existing native controls:
> To add more information to this issue. This property supports three values, auto, thin and none. These match nicely to WebKit's ScrollbarControlSize::Regular and ScrollbarControlSize::Thin and not rendering the scrollbar.
https://github.com/WebKit/standards-positions/issues/133#iss...
> To add more information to this issue. This property supports three values, auto, thin and none. These match nicely to WebKit's ScrollbarControlSize::Regular and ScrollbarControlSize::Thin and not rendering the scrollbar.