* Fix QMenu item not having different color on hover
due to the color changes in #2220.
* Remove strong border on pressed Qt widgets
* Make button gradient more subtle
by changing gradient-start on hover instead of gradient-end.
* Apply QPushButton style to QSpinBox buttons
* Improve margin of QComboBox arrow
* Make button-bg same color as button-gradient-end
This makes the hover gradient more subtle.
fdaa65e064