jellyfin/MediaBrowser.UI/Resources/NotificationMessage.xaml

<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">

    <!--Content style. -->
    <Style TargetType="Grid" x:Key="NotificationContentStyle">
        <Setter Property="HorizontalAlignment" Value="Right"/>
        <Setter Property="VerticalAlignment" Value="Bottom"/>
        <Setter Property="Background" Value="#FF870F"/>
        <Setter Property="Margin" Value="0 0 0 20"/>
    </Style>

    <!--Content style. -->
    <Style TargetType="Grid" x:Key="NotificationContentInnerStyle">
        <Setter Property="HorizontalAlignment" Value="Center"/>
        <Setter Property="MaxWidth" Value="500"/>
        <Setter Property="Margin" Value="0 0 20 0"/>
    </Style>

    <!--Message caption style. -->
    <Style TargetType="TextBlock" x:Key="NotificationCaptionStyle">
        <Setter Property="FontSize" Value="{DynamicResource Heading2FontSize}"/>
        <Setter Property="FontFamily" Value="{DynamicResource Heading2FontFamily}"/>
        <Setter Property="FontWeight" Value="{DynamicResource Heading2FontWeight}"/>
        <Setter Property="Foreground" Value="{DynamicResource Heading2Foreground}"/>
        <Setter Property="TextWrapping" Value="Wrap" />
        <Setter Property="Margin" Value="20 20 20 0" />
    </Style>

    <!--Message caption style. -->
    <Style TargetType="TextBlock" x:Key="NotificationTextStyle">
        <Setter Property="FontSize" Value="{DynamicResource DefaultFontSize}"/>
        <Setter Property="FontFamily" Value="{DynamicResource DefaultFontFamily}"/>
        <Setter Property="FontWeight" Value="{DynamicResource DefaultFontWeight}"/>
        <Setter Property="Foreground" Value="{DynamicResource DefaultForeground}"/>
        <Setter Property="TextWrapping" Value="Wrap" />
        <Setter Property="Margin" Value="20 20 20 0" />
    </Style>

    <!--Modal button image -->
    <Style TargetType="Image" x:Key="NotificationButtonImage" BasedOn="{StaticResource ModalButtonImage}">
        <Setter Property="Margin" Value="20 20 0 20" />
    </Style>
</ResourceDictionary>