Boris/BorisProject/MainWindow.xaml

<Window x:Class="BorisProject.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:BorisProject"
        mc:Ignorable="d"
        Title="MainWindow" Height="400" Width="300" WindowStartupLocation="CenterScreen" ResizeMode="NoResize" WindowStyle="None">
    <Grid>
        <Grid.Background>
            <LinearGradientBrush EndPoint="0.5,1" StartPoint="0.5,0">
                <GradientStop Color="Black" Offset="0"/>
                <GradientStop Color="#FF02FAFF" Offset="0.206"/>
            </LinearGradientBrush>
        </Grid.Background>
        <Label Content="Авторизация" HorizontalAlignment="Center" VerticalContentAlignment="Center"  VerticalAlignment="Center"   FontSize="20" Height="46" Width="138" Margin="81,81,81,273"/>
        <Label Content="Логин:" HorizontalAlignment="Left" Margin="35,168,0,0" VerticalAlignment="Top" FontSize="20"/>
        <Label Content="Пароль:" HorizontalAlignment="Left" Margin="35,212,0,0" VerticalAlignment="Top" FontSize="20" Width="82"/>
        <TextBox Name="logintxt" HorizontalAlignment="Left" Margin="119,177,0,0"  VerticalAlignment="Top" Height="24" Width="123" MaxLength="10"/>
        <PasswordBox Name="passwordpsw" HorizontalAlignment="Left" Margin="119,222,0,0" VerticalAlignment="Top" Width="123" Height="24" MaxLength="10"/>
        <Button Content="Войти" HorizontalAlignment="Center"  VerticalAlignment="Center" Width="88" Height="28" Margin="106,304,106,68" Click="Vhod_Click"/>
        <Button Content="X" FontSize="25" HorizontalAlignment="Left" Margin="265,0,0,0" VerticalAlignment="Top" Width="35" Height="35" Click="Exit_Click"/>
    </Grid>
</Window>