I create a pyqt window without any title bar and transparent. Also added blue border for my window but when on running the app I can't see any blue border for the window.

```
from PyQt5.QtWidgets import * 
from PyQt5.QtGui import * 
from PyQt5.QtCore import Qt
import sys

class Window(QMainWindow):
    def __init__(self):
        super().__init__()

        # this will hide the title bar
        self.setWindowFlag(Qt.FramelessWindowHint)
        self.setStyleSheet("border : 3px solid blue;")
        self.setWindowOpacity(0.01)
        # setting  the geometry of window
        self.setGeometry(100, 100, 400, 300)
        self.showFullScreen()

# create pyqt5 app
App = QApplication(sys.argv)

# create the instance of our Window
window = Window()
window.show()
# start the app
sys.exit(App.exec())

```

How can I show the border for my window?