Созданный пользовательский интерфейс в Qt designer не выглядит одинаково при запуске кода Python

Почему приложение в Qt Designer выглядит по другому после форматирования ui файла в py(код после форматирования я не менял) Помогите пожалуйста

Вот так выглядит сам код:

from PyQt5 import QtCore, QtGui, QtWidgets


class Ui_MainWindow(object):
    def setupUi(self, MainWindow):
        MainWindow.setObjectName("MainWindow")
        MainWindow.setEnabled(True)
        MainWindow.resize(845, 535)
        sizePolicy = QtWidgets.QSizePolicy(QtWidgets.QSizePolicy.Preferred, QtWidgets.QSizePolicy.Preferred)
        sizePolicy.setHorizontalStretch(0)
        sizePolicy.setVerticalStretch(0)
        sizePolicy.setHeightForWidth(MainWindow.sizePolicy().hasHeightForWidth())
        MainWindow.setSizePolicy(sizePolicy)
        MainWindow.setMinimumSize(QtCore.QSize(845, 535))
        MainWindow.setMaximumSize(QtCore.QSize(845, 535))
        MainWindow.setSizeIncrement(QtCore.QSize(0, 0))
        MainWindow.setBaseSize(QtCore.QSize(0, 0))
        font = QtGui.QFont()
        font.setFamily("Century Gothic")
        font.setPointSize(9)
        font.setKerning(True)
        MainWindow.setFont(font)
        MainWindow.setMouseTracking(False)
        MainWindow.setTabletTracking(False)
        MainWindow.setFocusPolicy(QtCore.Qt.StrongFocus)
        MainWindow.setContextMenuPolicy(QtCore.Qt.DefaultContextMenu)
        MainWindow.setAcceptDrops(False)
        MainWindow.setToolTipDuration(-1)
        MainWindow.setStatusTip("")
        MainWindow.setWhatsThis("")
        MainWindow.setAccessibleName("")
        MainWindow.setAccessibleDescription("")
        MainWindow.setAutoFillBackground(False)
        MainWindow.setWindowFilePath("")
        MainWindow.setIconSize(QtCore.QSize(24, 24))
        MainWindow.setAnimated(False)
        MainWindow.setDocumentMode(False)
        MainWindow.setDockNestingEnabled(False)
        MainWindow.setDockOptions(QtWidgets.QMainWindow.AllowTabbedDocks|QtWidgets.QMainWindow.ForceTabbedDocks|QtWidgets.QMainWindow.GroupedDragging|QtWidgets.QMainWindow.VerticalTabs)
        MainWindow.setUnifiedTitleAndToolBarOnMac(False)
        self.centralwidget = QtWidgets.QWidget(MainWindow)
        self.centralwidget.setObjectName("centralwidget")
        self.calendarWidget = QtWidgets.QCalendarWidget(self.centralwidget)
        self.calendarWidget.setEnabled(True)
        self.calendarWidget.setGeometry(QtCore.QRect(45, 155, 800, 381))
        self.calendarWidget.setMinimumSize(QtCore.QSize(800, 381))
        self.calendarWidget.setMaximumSize(QtCore.QSize(800, 381))
        font = QtGui.QFont()
        font.setFamily("Century Gothic")
        font.setPointSize(15)
        font.setKerning(True)
        self.calendarWidget.setFont(font)
        self.calendarWidget.setAutoFillBackground(True)
        self.calendarWidget.setStyleSheet("color: rgb(0, 0, 0);\n"
"selection-color: rgb(45, 86, 100);\n"
"selection-background-color: rgb(205, 217, 226);\n"
"")
        self.calendarWidget.setGridVisible(False)
        self.calendarWidget.setSelectionMode(QtWidgets.QCalendarWidget.SingleSelection)
        self.calendarWidget.setHorizontalHeaderFormat(QtWidgets.QCalendarWidget.SingleLetterDayNames)
        self.calendarWidget.setVerticalHeaderFormat(QtWidgets.QCalendarWidget.NoVerticalHeader)
        self.calendarWidget.setDateEditEnabled(False)
        self.calendarWidget.setDateEditAcceptDelay(1500)
        self.calendarWidget.setObjectName("calendarWidget")
        self.frame = QtWidgets.QFrame(self.centralwidget)
        self.frame.setGeometry(QtCore.QRect(45, 155, 41, 28))
        self.frame.setMinimumSize(QtCore.QSize(41, 28))
        self.frame.setMaximumSize(QtCore.QSize(41, 28))
        self.frame.setStyleSheet("background-color: rgb(205, 217, 226);\n"
"border-color: rgb(205, 217, 226);")
        self.frame.setFrameShape(QtWidgets.QFrame.StyledPanel)
        self.frame.setFrameShadow(QtWidgets.QFrame.Raised)
        self.frame.setObjectName("frame")
        self.frame_2 = QtWidgets.QFrame(self.centralwidget)
        self.frame_2.setGeometry(QtCore.QRect(807, 155, 41, 28))
        self.frame_2.setMinimumSize(QtCore.QSize(41, 28))
        self.frame_2.setMaximumSize(QtCore.QSize(41, 28))
        self.frame_2.setStyleSheet("background-color: rgb(205, 217, 226);\n"
"border-color: rgb(205, 217, 226);")
        self.frame_2.setFrameShape(QtWidgets.QFrame.StyledPanel)
        self.frame_2.setFrameShadow(QtWidgets.QFrame.Raised)
        self.frame_2.setObjectName("frame_2")
        MainWindow.setCentralWidget(self.centralwidget)

        self.retranslateUi(MainWindow)
        QtCore.QMetaObject.connectSlotsByName(MainWindow)

    def retranslateUi(self, MainWindow):
        _translate = QtCore.QCoreApplication.translate
        MainWindow.setWindowTitle(_translate("MainWindow", "MainWindow"))


if __name__ == "__main__":
    import sys
    app = QtWidgets.QApplication(sys.argv)
    MainWindow = QtWidgets.QMainWindow()
    ui = Ui_MainWindow()
    ui.setupUi(MainWindow)
    MainWindow.show()
    sys.exit(app.exec_())