如何使用qt样式表仅定制部分qwidget边框？

#include <QApplication>
#include <QWidget>
#include <QVBoxLayout>
#include <QPushButton>
#include <QFrame>

int main(int argc, char *argv[])
{
    QApplication app(argc, argv);

    QWidget window;
    QVBoxLayout *layout = new QVBoxLayout(&window);

    QPushButton *button1 = new QPushButton("Button 1");
    QPushButton *button2 = new QPushButton("Button 2");

    QFrame *frame = new QFrame();
    frame->setFrameShape(QFrame::StyledPanel);
    frame->setFrameShadow(QFrame::Sunken);

    // 设置button1的边框样式
    button1->setStyleSheet("QPushButton { border: 2px solid red; }");

    // 设置button2的边框样式
    button2->setStyleSheet("QPushButton { border: 2px solid blue; border-radius: 5px; }");

    // 设置frame的边框样式
    frame->setStyleSheet("QFrame { border: 3px dashed green; }");

    layout->addWidget(button1);
    layout->addWidget(button2);
    layout->addWidget(frame);

    window.show();
    return app.exec();
}