BeautySalon/MainWindow.xaml

<Window x:Class="BeautySalon.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        xmlns:local="clr-namespace:BeautySalon"
        mc:Ignorable="d"
        WindowStartupLocation="CenterScreen"
        MinHeight="550"
        MinWidth="800"
        Title="Салон красоты" Height="550" Width="800">
    <Grid>
        <Grid.RowDefinitions>
            <RowDefinition Height="75"/>
            <RowDefinition Height="*"/>
            <RowDefinition Height="30"/>
        </Grid.RowDefinitions>

        <Grid Grid.Row="0"  
              Background="#FFFF4A6D">
            
            <Button Name="SwitchEntitiesTableBtn"
                    Visibility="Hidden"
                    Content="Записи"
                    Width="150"
                    Height="20"
                    HorizontalAlignment="Left"
                    VerticalAlignment="Top"
                    Margin="100 10 0 0" 
                    Click="SwitchEntitiesTableBtn_Click"/>
            
            <Button Name="SwitchServicesTableBtn"
                    Visibility="Hidden"
                    Content="Услуги"
                    Width="150"
                    Height="20"
                    HorizontalAlignment="Left"
                    VerticalAlignment="Bottom"
                    Margin="100 0 0 10"
                    Click="SwitchServicesTableBtn_Click"/>

            <TextBox Name="InputAdminPassTxb"
                     Width="100"
                     Height="40"
                     FontSize="20"
                     HorizontalAlignment="Center"
                     Margin="500 0 0 0"
                     VerticalContentAlignment="Center"/>
            <Button Name="AdminModeBtn"
                    FontSize="20"
                    Content="Админ"
                    VerticalAlignment="Center"
                    HorizontalAlignment="Right"
                    Margin="0 0 20 0"
                    Click="AdminModeBtn_Click"/>
        </Grid>
        

        <Image Source="Resources/beauty_logo.png"
               HorizontalAlignment="Left"/>

        <TextBlock Text="Бархатные бровки"
                   HorizontalAlignment="Center"
                   VerticalAlignment="Center"
                   FontSize="30"
                   FontFamily="Tahoma"/>

        <Frame Grid.Row="1"
               Name="MainFrame"
               NavigationUIVisibility="Hidden"
               Source="Pages/ServicePage.xaml"/>

        <Grid Grid.Row="2"
              Background="#FFE1E4FF"/>

    </Grid>
</Window>