Shaker/Avalonia/SukiUI/Theme/BorderStyles.xaml

<Styles xmlns="https://github.com/avaloniaui" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">

    <Design.PreviewWith>
        <WrapPanel HorizontalAlignment="Center"
                   Background="{DynamicResource SukiBackground}"
                   Orientation="Horizontal">
            <Border Width="100"
                    Height="100"
                    Classes="GradientCard" />
        </WrapPanel>
    </Design.PreviewWith>

    <Style Selector="Border.Card">
        <Setter Property="Padding" Value="20" />
        <Setter Property="CornerRadius" Value="{DynamicResource MediumCornerRadius}" />
        <Setter Property="BorderThickness" Value="1" />
        <Setter Property="BorderBrush" Value="{DynamicResource SukiBorderBrush}" />
        <Setter Property="Background" Value="{DynamicResource SukiCardBackground}" />
    </Style>

    <Style Selector="Border.GradientCard">
        <Setter Property="Padding" Value="20" />
        <Setter Property="CornerRadius" Value="{DynamicResource MediumCornerRadius}" />
        <Setter Property="BorderThickness" Value="1" />
        <Setter Property="BorderBrush" Value="{DynamicResource SukiBorderBrush}" />
        <Setter Property="Background">
            <RadialGradientBrush Center="120%,-220%" GradientOrigin="120%,-220%" Radius="3">
                <GradientStop Offset="0.4" Color="{DynamicResource SukiPrimaryColor}" />
                <GradientStop Offset="1" Color="Transparent" />
            </RadialGradientBrush>
        </Setter>
        <Setter Property="Margin" Value="7" />
    </Style>

    <Style Selector="Border.ElevatedCard">
        <Setter Property="Padding" Value="20" />
        <Setter Property="CornerRadius" Value="{DynamicResource MediumCornerRadius}" />
        <Setter Property="BorderThickness" Value="1" />
        <Setter Property="BorderBrush" Value="{DynamicResource SukiBorderBrush}" />
        <Setter Property="Background" Value="{DynamicResource SukiBackground}" />
        <Setter Property="Margin" Value="7" />
        <Setter Property="BoxShadow" Value="{DynamicResource SukiPopupShadow}" />
    </Style>

    <Style Selector="Border.Hoverable:pointerover">
        <Setter Property="BoxShadow" Value="0 0 7 0 LightGray" />
    </Style>
</Styles>