PYQT5 QSS :hover无效

from PyQt5 import QtCore, QtGui, QtWidgets
from PyQt5.QtWidgets import QMessageBox

class Ui_login_page:
def setupUi(self, login_page):
login_page.setObjectName("login_page")
login_page.setEnabled(True)
# 设置登录窗大小，并设置为不可最大化
login_page.resize(480, 300)
login_page.setWindowFlags(QtCore.Qt.MSWindowsFixedSizeDialogHint)
# 设置登录窗标题图标
icon = QtGui.QIcon()
icon.addPixmap(QtGui.QPixmap("image/logo.ico"), QtGui.QIcon.Normal,
QtGui.QIcon.Off)
login_page.setWindowIcon(icon)
# 设置窗口背景色
login_page.setStyleSheet("#login_page{background-color:lightblue}")
# 创建窗口对象
self.centralwidget = QtWidgets.QWidget(login_page)
self.centralwidget.setObjectName("centralwidget")
# 设置”账号“标签
self.user_lab = QtWidgets.QLabel(self.centralwidget)
self.user_lab.setGeometry(QtCore.QRect(80, 135, 91, 31))
font = QtGui.QFont()
font.setFamily("仿宋")
font.setPointSize(15)
self.user_lab.setFont(font)
self.user_lab.setAlignment(QtCore.Qt.AlignRight)
self.user_lab.setObjectName("user_lab")
# 设置“密码”标签
self.psw_lab = QtWidgets.QLabel(self.centralwidget)
self.psw_lab.setGeometry(QtCore.QRect(80, 185, 91, 31))
font = QtGui.QFont()
font.setFamily("仿宋")
font.setPointSize(15)
self.psw_lab.setFont(font)
self.psw_lab.setAlignment(QtCore.Qt.AlignRight)
self.psw_lab.setObjectName("psw_lab")
# 设置“账号”输入框
self.user_entry = QtWidgets.QLineEdit(self.centralwidget)
self.user_entry.setGeometry(QtCore.QRect(190, 135, 201, 27))
self.user_entry.setObjectName("user_entry")
self.user_entry.setPlaceholderText('请输入用户名')
self.user_entry.setFocus()
self.user_entry.setClearButtonEnabled(True)
# 设置“密码”输入框
self.psw_entry = QtWidgets.QLineEdit(self.centralwidget)
self.psw_entry.setGeometry(QtCore.QRect(190, 185, 201, 27))
self.psw_entry.setObjectName("psw_entry")
self.psw_entry.setPlaceholderText('请输入密码')
self.psw_entry.setEchoMode(QtWidgets.QLineEdit.Password)
self.psw_entry.setClearButtonEnabled(True)
# 设置登录按钮
self.sign_btu = QtWidgets.QPushButton(self.centralwidget)
self.sign_btu.setGeometry(QtCore.QRect(190, 230, 100, 30))
font = QtGui.QFont()
font.setFamily("仿宋")
font.setPointSize(15)
self.sign_btu.setFont(font)
self.sign_btu.setObjectName("sign_btu")
StyleSheet = '''QPushButton#sign_btu{background-color: #FFFFFF; border-radius:5px;}
QPushButton#sign_btu : hover {background-color: red;}
QPushButton#sign_btu : pressed{background-color: #808080;}'''
self.sign_btu.setStyleSheet(StyleSheet)
self.sign_btu.clicked.connect(self.login_click)
# 设置背景图片：login.png
self.log_lab = QtWidgets.QLabel(self.centralwidget)
self.log_lab.setGeometry(QtCore.QRect(63, 15, 354, 106))
self.log_lab.setText("")
self.log_lab.setPixmap(QtGui.QPixmap(":/png/login.png"))
self.log_lab.setObjectName("log_lab")
login_page.setCentralWidget(self.centralwidget)
self.retranslateUi(login_page)
QtCore.QMetaObject.connectSlotsByName(login_page)

def retranslateUi(self, login_page):
    _translate = QtCore.QCoreApplication.translate
    login_page.setWindowTitle(_translate("login_page", "用户登录"))
    self.user_lab.setText(_translate("login_page", "用户名："))
    self.psw_lab.setText(_translate("login_page", "密  码："))
    self.sign_btu.setText(_translate("login_page", "登 录"))

def login_click(self):
    user = self.user_entry.text()
    pwd = self.psw_entry.text()
    if user != '' and pwd != '':
        if user == 'adm':
            if pwd == '123456':
                QtWidgets.QMessageBox.information(self.sign_btu, '登录成功',
                                                  '欢迎使用本系统',
                                                  QMessageBox.Ok)
            else:
                QtWidgets.QMessageBox.critical(self.sign_btu, '密码错误',
                                                  '您所输入的密码错误',
                                                  QMessageBox.Ok)
        else:
            QtWidgets.QMessageBox.critical(self.sign_btu, '用户名错误',
                                           '您所输入的用户名不存在',
                                           QMessageBox.Ok)
    else:
        QtWidgets.QMessageBox.critical(self.sign_btu, '用户名或密码错误',
                                       '用户名或密码不能为空', QMessageBox.Ok)

import image_rc

import sys

if name == 'main':
app = QtWidgets.QApplication(sys.argv)
MainWindow = QtWidgets.QMainWindow()
ui = Ui_login_page()
ui.setupUi(MainWindow)
MainWindow.show()
sys.exit(app.exec_())

求高人给指点下，QSS设置伪状态没有效果呀

你的stylesheet应该这么写

self.sign_btu.setStyleSheet("QPushButton{background: rgb(69,133,254);border:none;text-align:left;color:white;}"
        "QPushButton:hover{background-color:qlineargradient(spread:pad, x1:0, y1:0, x2:1, y2:0, stop:0 rgba(50,197,255,1),stop:1 rgba(50,197,255,0));border:none;}");

这样就有移入效果了