Setting a transparent background to QScrollbar using stylesheets

[Rachol]

Yes, there is some bug/feature in rendering the background for scrollbar

In my opinion the implementation of drawing widgets with stylesheets is a little bit messy. Certain parts are drawn using stylesheets, some other using current style, some other hardcoded style. Therefore if you run your application on Linux, you don't get the problem that you get on your Windows machine.

Try to run your app with different style that Windows default and see what happens