@KillerSmath fix did the work, combined with @mrjj QGroupButton! I added this code to style the pressed button

void MainWindow::onGroupButtonClicked(int btn_id) { g_btns->button(btn_id)->setStyleSheet(QString("QPushButton {color: #444444; background: #cccccc; border: 2px solid #cccccc; border-width: 0px 0px 2px 0px;} QPushButton:hover {border: 2px black solid; color: #333333; background-color: #F7F7F7;} QPushButton:pressed {background: #cccccc;}")); }

Thanks a lot guys!

@legitnameyo This is not how it works. You will need to subclass QPushButton and override http://doc.qt.io/qt-5/qwidget.html#mousePressEvent
You can find an example here: http://doc.qt.io/qt-5/qtwidgets-widgets-scribble-example.html

That's not valid css. border does not take 4 separate width parameters, only one shared across all sides. If you want to set borders different for each side you need to use border-width:

border: solid #000000; border-width: 0px 0px 2px 0px;

It works,

thanks a lot