I can't find anything on this topic, is it possible to use CSS files in Qt or do I have to use setStyleSheet on every element I want to style?
I can't say its very maintainable if I have to write all the styles in quotes.
You can use -stylesheet to specify a stylesheet on the command line. In addition, you could load your .qss file from a file or a resource and then call setStylesheet on your QApplication instance.
QFile stylesheet(":<prefix>/<alias") and then reading in the text. Perhaps: stylesheet.open(QIODevice::ReadOnly); QTextStream ts(&stylesheet); a.setStyleSheet(ts.readAll());