QTabWidget:pane {
  border-top: 1px solid  rgba(0, 0, 0, 150);
}

QTabBar:tab {
  width: 30px;
  height: 50px;
  background-color: qlineargradient(spread:pad, x1:0, y1:0, x2:1, y2:0, stop:0 rgba(180, 180, 180, 255), stop:1 rgba(220, 220, 220, 255));
  border-top: 1px solid  rgba(0, 0, 0, 150);
  border-right: 1px solid  rgba(0, 0, 0, 150);
  margin: 0px;
  padding-top: -15px;
  padding-bottom: 15px;
}

QTabBar:tab:selected {
  background-color: qlineargradient(spread:pad, x1:0, y1:0, x2:1, y2:0, stop:0 rgba(160, 160, 160, 255), stop:1 rgba(220, 220, 220, 255));
}

## to tab stylesheet

QWidget {
  background-color: qlineargradient(spread:pad, x1:0, y1:0, x2:1, y2:0, stop:0 rgba(220, 220, 220, 255), stop:1 rgba(250, 250, 250, 255));
}