Problem with setting font via stylesheet

Hello. In my app I need to put three plain textboxes in three tabs. I'm trying to set the font of the textboxes via stylesheets but I seem to be doing something wrong -- can anyone help?

I looked up the documentation and it said that for QTextEdits I should set the style for QAbstractScrollArea but still it is not working. I'm using a QPlainTextEdit -- is that a problem?

The code is:

Code:

# include <QtGui/QApplication>
# include <QtGui/QPlainTextEdit>
# include <QtGui/QTabWidget>
 
int main ( int argc, char * argv [] )
{
        QApplication app ( argc, argv ) ;
        app . setStyleSheet ( "QAbstractScrollArea { font : \"DejaVu Sans\" }" ) ;
 
        QPlainTextEdit * myInput = new QPlainTextEdit ;
 
        QPlainTextEdit * stdOutput = new QPlainTextEdit ;
        stdOutput -> setReadOnly ( true ) ;
 
        QPlainTextEdit * stdError = new QPlainTextEdit ;
        stdError -> setReadOnly ( true ) ;
 
        QTabWidget * tabWidget = new QTabWidget ;
        tabWidget -> addTab ( myInput, "Input" ) ;
        tabWidget -> addTab ( stdOutput, "Output" ) ;
        tabWidget -> addTab ( stdError, "Errors" ) ;
 
        tabWidget -> show () ;
        return app . exec () ;
}

Any help is appreciated. Thanks.