Increase scrollbar thumb size on hover

[niftytyro]

Scroll bar is very thin right now. Specially in the huge builtins blog, it looks like a pale dot. Idea is to animate it to a bigger size when i hover over the whole sidebar track. Also, when the scroll thumb's height is less than a certain threshold, the height should get bigger on hovering too maybe?

[tusharsadhwani]

It seems scrollbar events aren't that good with css itself. It might work with javascript.

[niftytyro]

I think we can make them work. 🤔