XAML

<Page
    x:Class="App15.MainPage"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:local="using:App15"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    mc:Ignorable="d">

    <Grid x:Name="LayoutRoot" Background="Black">
        <Button Content="Gomb1" HorizontalAlignment="Left" Margin="10,10,0,0" VerticalAlignment="Top">
            <Button.Background>
                <LinearGradientBrush EndPoint="0.5,1" StartPoint="0.5,0">
                    <GradientStop Color="Black"/>
                    <GradientStop Color="#FF5D2121" Offset="1"/>
                </LinearGradientBrush>
            </Button.Background>
        </Button>
        <Button Content="Gomb2" HorizontalAlignment="Left" Margin="1273,10,0,0" VerticalAlignment="Top" Background="#FF362424"/>
        <Button Content="Gomb3" HorizontalAlignment="Left" Margin="10,720,0,0" VerticalAlignment="Top" Background="#FF573939"/>
        <Button Content="Gomb4" HorizontalAlignment="Left" Margin="1273,720,0,0" VerticalAlignment="Top">
            <Button.Background>
                <LinearGradientBrush EndPoint="0.5,1" StartPoint="0.5,0">
                    <GradientStop Color="Black"/>
                    <GradientStop Color="#FF5D3535" Offset="1"/>
                </LinearGradientBrush>
            </Button.Background>
        </Button>
    </Grid>
</Page>