QSlider.qss

QSlider::groove:horizontal {
    border: 0px solid transparent;
    height: 8px;
    background: #eeeeee;
    margin: 2px 0;
}

QSlider::handle:horizontal {
    background-color: #8e24aa;
    height: 10px;
    width: 12px;
    border: 0px solid transparent;
    margin: -2px 0;
    border-radius: 6px;
}

QSlider::handle:horizontal:pressed {
    background-color: #8e24aa;
    height: 10px;
    width: 18px;
    border: 0px solid transparent;
    margin: -5px 0px;
    border-radius: 9px;
}

QSlider::handle:horizontal:disabled {
    background-color: #bbbbbb;
    height: 2px;
    width: 8px;
    border: 0px solid transparent;
    margin: -1px -1px;
    border-radius: 4px;
}

QSlider::groove:vertical {
    border: 0px solid transparent;
    width: 8px;
    background: #eeeeee;
    margin: 2px 0;
}

QSlider::handle:vertical {
    background-color: #8e24aa;
    height: 12px;
    width: 6px;
    border: 0px solid transparent;
    margin: 0 -2px;
    border-radius: 6px;
}

QSlider::handle:vertical:pressed {
    background-color: #8e24aa;
    height: 18px;
    width: 6px;
    border: 0px solid transparent;
    margin: 0 -5px;
    border-radius: 9px;
}

QSlider::handle:vertical:disabled {
    background-color: #bbbbbb;
    height: 8px;
    width: 2px;
    border: 0px solid transparent;
    margin: -1px -1px;
    border-radius: 4px;
}