Code WPF Calculator2

<Window x:Class="Calc2.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:Calc2"
    mc:Ignorable="d"
    Title="Calculator" Height="450" Width="350">
    <Grid Background="Black">
        <Grid.RowDefinitions>
            <RowDefinition Height="*" />
            <RowDefinition Height="*" />
            <RowDefinition Height="4*" />
        </Grid.RowDefinitions>
        <TextBox Grid.Row="0" Text="123" Margin="5" FontSize="40"/>
        <TextBox Grid.Row="1" Text="123" Margin="5" FontSize="40"/>
        <Grid Grid.Row="2">
            <Grid.RowDefinitions>
                <RowDefinition />
                <RowDefinition />
                <RowDefinition />
                <RowDefinition />
            </Grid.RowDefinitions>
            <Grid.ColumnDefinitions>
                <ColumnDefinition />
                <ColumnDefinition />
                <ColumnDefinition />
                <ColumnDefinition />
                <ColumnDefinition />
            </Grid.ColumnDefinitions>

            <Button Grid.Row="0" Grid.Column="0" Content="7" Background="#FF95E2D0" FontSize="33" />
            <Button Grid.Row="0" Grid.Column="1" Content="8" Background="#FF95E2D0" FontSize="33" />
            <Button Grid.Row="0" Grid.Column="2" Content="9" Background="#FF95E2D0" FontSize="33" />
            <Button Grid.Row="0" Grid.Column="3" Content="+" FontSize="33" Background="#FFD4A5A5" />
            <Button Grid.Row="0" Grid.Column="4" Content="-" FontSize="33" Background="#FFD4A5A5" />
            <Button Grid.Row="1" Grid.Column="0" Content="4" Background="#FF95E2D0" FontSize="33" />
            <Button Grid.Row="1" Grid.Column="1" Content="5" Background="#FF95E2D0" FontSize="33" />
            <Button Grid.Row="1" Grid.Column="2" Content="6" Background="#FF95E2D0" FontSize="33" />
            <Button Grid.Row="1" Grid.Column="3" Content="*" FontSize="33" Background="#FFD4A5A5" />
            <Button Grid.Row="1" Grid.Column="4" Content="/" FontSize="33" Background="#FFD4A5A5" />
            <Button Grid.Row="2" Grid.Column="0" Content="1" Background="#FF95E2D0" FontSize="33" />
            <Button Grid.Row="2" Grid.Column="1" Content="2" Background="#FF95E2D0" FontSize="33" />
            <Button Grid.Row="2" Grid.Column="2" Content="3" Background="#FF95E2D0" FontSize="33" />
            <Button Grid.Row="2" Grid.Column="3" Content="C" Grid.ColumnSpan="2" FontSize="33" Background="#FFD4A5A5" />
            <Button Grid.Row="3" Grid.Column="0" Content="0" FontSize="33" Background="#FF66BFE0" />
            <Button Grid.Row="3" Grid.Column="1" Content="," FontSize="33" Background="#FF66BFE0" />
            <Button Grid.Row="3" Grid.Column="2" Content="+/-" FontSize="33" Background="#FF66BFE0" />
            <Button Grid.Row="3" Grid.Column="3" Content="=" Grid.ColumnSpan="2" FontSize="33" Background="#FFF9C27F" />
        </Grid>
    </Grid>
</Window>