title: Hover animation does not work in QSS in PyQT5
body: <p>I am trying to create my first UI in PyQT5. However, I am unable to add a hover-animation to my button and I can't figure out why it does not work.</p>
  <p>I am trying it with this stylesheet, instead off QPushButton#authenticate_button:hover I also tried #authenticate_button and QPushButton, nothing seems to work :</p>
  <pre><code>self.background_window.setStyleSheet(&quot;#authenticate_button {\n&quot;
                                      &quot;color: white;\n&quot;
                                      &quot;background-color: qlineargradient(x1: 0, y1: 0, x2: 1, y2: 1,stop: 0 rgba(0,145,224,255), stop: 1 rgba(0,250,215,255)) ;\n&quot;
                                      &quot;border-radius: 0;\n&quot;
                                      &quot;border-radius: 20px;\n&quot;
                                      &quot;}\n&quot;
                                      &quot;\n&quot;
                                      &quot;#background_window {\n&quot;
                                      &quot;border-radius: 10px;\n&quot;
                                      &quot;background-color: rgb(50, 50, 50);\n&quot;
                                      &quot;}\n&quot;
                                      &quot;\n&quot;
                                      &quot;#key_textfield {\n&quot;
                                      &quot;background-color: transparent;\n&quot;
                                      &quot;border: 2px solid grey;\n&quot;
                                      &quot;border-radius: 10px;\n&quot;
                                      &quot;}\n&quot;
                                      &quot;QPushButton#authenticate_button:hover {\n&quot;
                                      &quot;border-radius: 30px;\n&quot;
                                      &quot;}\n&quot;
                                      &quot;&quot;)
  </code></pre>
  <p>It currently looks like this, however there is no change, when I hover over the element.</p>
  <p><a href="https://i.stack.imgur.com/sZQeA.gif" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/sZQeA.gif" alt="Issue" /></a></p>
  <p>This is the whole code, sorry I tried to shorten it as much as I can, but I do not want to leave out important details:</p>
  <pre><code>class Ui_authenticate_window(object):
      def setupUi(self, authenticate_window):
          authenticate_window.setObjectName(&quot;authenticate_window&quot;)
          authenticate_window.setEnabled(False)
          authenticate_window.resize(300, 450)
          authenticate_window.setMaximumSize(QtCore.QSize(300, 450))
  
          self.centralwidget = QtWidgets.QWidget(authenticate_window)
          self.centralwidget.setEnabled(False)
  
       
          self.background_window = QtWidgets.QFrame(self.centralwidget)
          self.background_window.setGeometry(QtCore.QRect(10, 60, 280, 380))
          self.background_window.setStyleSheet(&quot;#authenticate_button {\n&quot;
                                              &quot;color: white;\n&quot;
                                              &quot;background-color: qlineargradient(x1: 0, y1: 0, x2: 1, y2: 1,stop: 0 rgba(0,145,224,255), stop: 1 rgba(0,250,215,255)) ;\n&quot;
                                              &quot;border-radius: 0;\n&quot;
                                              &quot;border-radius: 20px;\n&quot;
                                              &quot;}\n&quot;
                                              &quot;\n&quot;
                                              &quot;#background_window {\n&quot;
                                              &quot;border-radius: 10px;\n&quot;
                                              &quot;background-color: rgb(50, 50, 50);\n&quot;
                                              &quot;}\n&quot;
                                              &quot;\n&quot;
                                              &quot;#key_textfield {\n&quot;
                                              &quot;background-color: transparent;\n&quot;
                                              &quot;border: 2px solid grey;\n&quot;
                                              &quot;border-radius: 10px;\n&quot;
                                              &quot;}\n&quot;
                                              &quot;QPushButton#authenticate_button:hover {\n&quot;
                                              &quot;border-radius: 30px;\n&quot;
                                              &quot;}\n&quot;
                                              &quot;&quot;)
  
          self.background_window.setObjectName(&quot;background_window&quot;)
          self.authenticate_button = QtWidgets.QPushButton(self.background_window)
        
          self.authenticate_button.setGeometry(QtCore.QRect(10, 320, 260, 41))
          font = QtGui.QFont()
          font.setFamily(&quot;Montserrat&quot;)
          font.setPointSize(11)
          font.setBold(True)
          font.setWeight(75)
          self.authenticate_button.setFont(font)
          
  
          self.authenticate_button.setObjectName(&quot;authenticate_button&quot;)
          
          self.key_textfield = QtWidgets.QLineEdit(self.background_window)
          self.key_textfield.setGeometry(QtCore.QRect(10, 270, 260, 25))
          font = QtGui.QFont()
          font.setFamily(&quot;Arial&quot;)
          self.key_textfield.setFont(font)
          self.key_textfield.setCursor(QtGui.QCursor(QtCore.Qt.ArrowCursor))
          self.key_textfield.setObjectName(&quot;key_textfield&quot;)
          self.logo_icon = QtWidgets.QToolButton(self.centralwidget)
          self.logo_icon.setGeometry(QtCore.QRect(100, 10, 100, 100))
          self.logo_icon.setStyleSheet(&quot;#logo_icon {\n&quot;
          &quot;background-color: transparent;\n&quot;
          &quot;}&quot;)
          
          creation_logo = QtGui.QIcon()
          creation_logo.addPixmap(QtGui.QPixmap(&quot;required/images/creation.ico&quot;), QtGui.QIcon.Disabled, QtGui.QIcon.Off)
          self.logo_icon.setIcon(creation_logo)
          self.logo_icon.setIconSize(QtCore.QSize(1000000, 100000))
          self.logo_icon.setObjectName(&quot;logo_icon&quot;)
          authenticate_window.setCentralWidget(self.centralwidget)
  
          self.retranslateUi(authenticate_window)
          QtCore.QMetaObject.connectSlotsByName(authenticate_window)
  
      def retranslateUi(self, authenticate_window):
          _translate = QtCore.QCoreApplication.translate
          authenticate_window.setWindowTitle(_translate(&quot;authenticate_window&quot;, &quot;creation. - Authentication.&quot;))
          self.authenticate_button.setText(_translate(&quot;authenticate_window&quot;, &quot;Authenticate.&quot;))
  </code></pre>