Qt 5 port of GNOME’s Adwaita theme

 Adwaita-Qt provides a port of Adwaita theme, which is the default style
 of GNOME, to Qt 5.
 .
 To use it, start your Qt applications with “-style Adwaita” parameter,
 or export QT_STYLE_OVERRIDE=Adwaita environment variable.
 For the dark version, use Adwaita-Dark instead of Adwaita.