Added Card control

StabilityMatrix.Avalonia/Controls/Card.cs

@@ -0,0 +1,23 @@
+using Avalonia.Controls;
+using Avalonia.Controls.Primitives;
+using Avalonia.Styling;
+
+namespace StabilityMatrix.Avalonia.Controls;
+
+public class Card : Expander
+{
+    public Card()
+    {
+        // Expander /template/ ToggleButton#PART_toggle
+        var customStyle = new Style(x =>
+            x.OfType<Expander>().Template().OfType<ToggleButton>().Name("PART_toggle"));
+        
+        customStyle.Setters.Add(new Setter
+        {
+            Property = IsVisibleProperty,
+            Value = false
+        });
+        
+        Styles.Add(customStyle);
+    }
+}

StabilityMatrix.Avalonia/Views/LaunchPageView.axaml

@@ -117,14 +117,9 @@
             VerticalScrollBarVisibility="Auto"
             FontFamily="Cascadia Code,Consolas,Menlo,Monospace" />
         
-            <Expander IsExpanded="True" Grid.Row="1" Header="Header Stuff" Margin="16">
-                <Expander.Styles>
-                    <Style Selector="Expander /template/ ToggleButton#PART_toggle">
-                        <Setter Property="IsVisible" Value="False"/>
-                    </Style>
-                </Expander.Styles>
-                <TextBlock Text="Hello World"></TextBlock>
-            </Expander>
+        <controls:Card IsExpanded="True" Grid.Row="1" Header="Header Stuff" Margin="16">
+            <TextBlock Text="Hello World"></TextBlock>
+        </controls:Card>
 
         <!--Command="{Binding LaunchWebUiCommand}"-->
         <!--Visibility="{Binding ShowWebUiButton, Converter={StaticResource BoolToVisConverter}}"-->