working margins

samples/ControlCatalog/MainWindow.xaml

@@ -66,20 +66,20 @@
       <v:CustomNotificationView />
     </DataTemplate>
   </Window.DataTemplates>
-  <Panel>  
+  <Panel>
     <Panel Margin="{Binding #MainWindow.OffScreenMargin}">
       <DockPanel LastChildFill="True" Margin="{Binding #MainWindow.WindowDecorationMargins}">
-      <Menu Name="MainMenu" DockPanel.Dock="Top">
-        <MenuItem Header="File">
-          <MenuItem Header="Exit" Command="{Binding ExitCommand}" />
-        </MenuItem>
-        <MenuItem Header="Help">
-          <MenuItem Header="About" Command="{Binding AboutCommand}" />
-        </MenuItem>
-      </Menu>
-      <local:MainView />
-    </DockPanel>
-    </Panel>    
+        <Menu Name="MainMenu" DockPanel.Dock="Top">
+          <MenuItem Header="File">
+            <MenuItem Header="Exit" Command="{Binding ExitCommand}" />
+          </MenuItem>
+          <MenuItem Header="Help">
+            <MenuItem Header="About" Command="{Binding AboutCommand}" />
+          </MenuItem>
+        </Menu>
+        <local:MainView />
+      </DockPanel>
+    </Panel>
     <Border IsVisible="{Binding ExtendClientAreaEnabled}" BorderThickness="1 1 1 0" CornerRadius="4 4 0 0" BorderBrush="#55000000" Height="22" VerticalAlignment="Top" HorizontalAlignment="Left" Margin="250 8 0 0">
       <Border.Background>
         <SolidColorBrush Color="White" Opacity="0.7" />

samples/ControlCatalog/ViewModels/MainWindowViewModel.cs

@@ -70,11 +70,6 @@ namespace ControlCatalog.ViewModels
                 {
                     ChromeHints = ExtendClientAreaChromeHints.NoChrome;
 
-                    if(x.Item1)
-                    {
-                        ChromeHints |= ExtendClientAreaChromeHints.SystemChromeButtons;
-                    }
-
                     if(x.Item2)
                     {
                         ChromeHints |= ExtendClientAreaChromeHints.ManagedChromeButtons;

src/Avalonia.Themes.Default/Window.xaml

@@ -5,7 +5,9 @@
   <Setter Property="Template">
     <ControlTemplate>
       <Panel>
-        <Border Name="PART_TransparencyFallback" IsHitTestVisible="False" Margin="{TemplateBinding WindowDecorationMargins}" />
+        <Panel IsHitTestVisible="False" Margin="{TemplateBinding OffScreenMargin}">
+          <Border Name="PART_TransparencyFallback" IsHitTestVisible="False" Margin="{TemplateBinding WindowDecorationMargins}" />
+        </Panel>
         <Border Background="{TemplateBinding Background}">
           <VisualLayerManager>
             <ContentPresenter Name="PART_ContentPresenter"