QTabBar {
    background-color: transparent;
    background-image: none; 
}
QTabBar::tab {
    margin-bottom: 5px;
    border: 1px solid #77d68787;
    padding: 5px 10px;
}
QTabBar::tab:first {
    border-top-left-radius: 4px;
    border-bottom-left-radius: 4px;
}
QTabBar::tab:last {
    border-top-right-radius: 4px;
    border-bottom-right-radius: 4px;
}
QTabBar::tab:only-one {
    border-radius: 4px;
}
QTabBar::close-button {
    margin-right: 20px;
}
QTabBar::tab:selected, QTabBar::tab:hover {
    background: qlineargradient(x1: 0, y1: 0, x2: 0, y2: 1,
                                stop: 0 #00000000, stop: 0.5 #33d68787, stop: 1.0 #66d68787);
    padding: 4px 10px 4px 10px;
    margin-top: 0px;
    margin-bottom: 3px;
}
QTabBar::tab:!selected {
    margin-top: 3px;
    margin-bottom: 6px;
}