StabilityMatrix/StabilityMatrix.Avalonia/Styles/Card.axaml

<ResourceDictionary xmlns="https://github.com/avaloniaui"
                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
                    xmlns:controls="clr-namespace:StabilityMatrix.Avalonia.Controls">
    <Design.PreviewWith>
        <Border Padding="20">
            <StackPanel>
                <controls:Card
                    Margin="8"
                    MaxHeight="450"
                    Name="ModelCard"
                    Width="330">
                    <TextBlock Text="Hello World" />
                </controls:Card>
            </StackPanel>
        </Border>
    </Design.PreviewWith>

    <ControlTheme x:Key="{x:Type controls:Card}" TargetType="controls:Card">
        <Setter Property="Background" Value="{DynamicResource ComboBoxBackground}"/>
        <Setter Property="BorderBrush" Value="{DynamicResource ComboBoxBorderBrush}" />
        <Setter Property="Foreground" Value="{DynamicResource ComboBoxForeground}" />
        <Setter Property="BorderThickness" Value="1" />
        <Setter Property="Padding" Value="14,16,14,16" />
        <Setter Property="HorizontalAlignment" Value="Stretch" />
        <Setter Property="VerticalAlignment" Value="Center" />
        <Setter Property="HorizontalContentAlignment" Value="Stretch" />
        <Setter Property="VerticalContentAlignment" Value="Center" />
        <Setter Property="FontSize" Value="{DynamicResource ControlContentThemeFontSize}" />
        <Setter Property="FontWeight" Value="Normal" />
        <Setter Property="Border.CornerRadius" Value="{DynamicResource ControlCornerRadius}" />
        <Setter Property="Focusable" Value="False" />
        <Setter Property="KeyboardNavigation.IsTabStop" Value="False" />
        <Setter Property="Template">
            <Setter.Value>
                <ControlTemplate>
                    <Grid>
                        <Border
                            x:Name="ContentBorder"
                            Padding="{TemplateBinding Padding}"
                            HorizontalAlignment="{TemplateBinding HorizontalAlignment}"
                            VerticalAlignment="{TemplateBinding VerticalAlignment}"
                            Background="{TemplateBinding Background}"
                            BorderBrush="{TemplateBinding BorderBrush}"
                            BorderThickness="{TemplateBinding BorderThickness}"
                            CornerRadius="{TemplateBinding Border.CornerRadius}">
                            <ContentPresenter
                                x:Name="ContentPresenter"
                                HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}"
                                VerticalAlignment="{TemplateBinding VerticalContentAlignment}" 
                                Content="{TemplateBinding Content}" />
                        </Border>
                    </Grid>
                </ControlTemplate>
            </Setter.Value>
        </Setter>
    </ControlTheme>
</ResourceDictionary>