QTabWidget: Styling QTabBar with a simple stylesheet overwrites other tab properties.

If a simple stylesheet to a QTabWidget's tabbar is applied in order to provide a red border to each tab, this results in the loss of all other style properties of the tab bar (e.g. margins). The native 'look and feel' of the tab bar seems to be overridden. Like:

QTabBar::tab {
border: 1px solid red;
}

Attaching sample code and output snapshot