Add EmbeddableControlRootTheme

src/AtomUI.Controls/AtomUIOSSControlThemesProvider.axaml

@@ -17,6 +17,7 @@
         <ResourceInclude Source="ComboBox/Themes/ComboBoxThemes.axaml" />
         <ResourceInclude Source="DatePicker/Themes/DatePickerThemes.axaml" />
         <ResourceInclude Source="Drawer/Themes/DrawerThemes.axaml" />
+        <ResourceInclude Source="Embedding/Themes/EmbeddableControlRootTheme.axaml" />
         <ResourceInclude Source="EmptyIndicator/Themes/EmptyIndicatorTheme.axaml" />
         <ResourceInclude Source="Expander/Themes/ExpanderTheme.axaml" />
         <ResourceInclude Source="Flyouts/Themes/FlyoutThemes.axaml" />

src/AtomUI.Controls/Embedding/Themes/EmbeddableControlRootTheme.axaml

@@ -0,0 +1,30 @@
+<ResourceDictionary
+    xmlns="https://github.com/avaloniaui"
+    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+    xmlns:atom="https://atomui.net">
+    <ControlTheme x:Key="{x:Type EmbeddableControlRoot}" TargetType="EmbeddableControlRoot">
+        <Setter Property="Template">
+            <ControlTemplate>
+                <Panel>
+                    <Border Name="{x:Static atom:EmbeddingThemeConstants.TransparencyFallbackPart}" IsHitTestVisible="False" />
+                    <Border Background="{TemplateBinding Background}">
+                        <VisualLayerManager>
+                            <ContentPresenter Name="{x:Static atom:EmbeddingThemeConstants.ContentPresenterPart}"
+                                              ContentTemplate="{TemplateBinding ContentTemplate}"
+                                              Content="{TemplateBinding Content}"
+                                              Margin="{TemplateBinding Padding}"/>
+                        </VisualLayerManager>
+                    </Border>
+                </Panel>
+            </ControlTemplate>
+        </Setter>
+        
+        <Setter Property="Background" Value="{DynamicResource {x:Static atom:WindowTokenKey.DefaultBackground}}" />
+        <Setter Property="TransparencyBackgroundFallback" Value="{DynamicResource {x:Static atom:WindowTokenKey.DefaultBackground}}" />
+        <Setter Property="TopLevel.SystemBarColor" Value="{DynamicResource {x:Static atom:WindowTokenKey.SystemBarColor}}" />
+        <Setter Property="Foreground" Value="{DynamicResource {x:Static atom:WindowTokenKey.DefaultForeground}}" />
+        <Setter Property="FontSize" Value="{DynamicResource {x:Static atom:SharedTokenKey.FontSize}}" />
+        <Setter Property="FontFamily" Value="{DynamicResource {x:Static atom:SharedTokenKey.FontFamily}}" />
+        
+    </ControlTheme>
+</ResourceDictionary>

src/AtomUI.Controls/Embedding/Themes/EmbeddingThemeConstants.cs

@@ -0,0 +1,7 @@
+namespace AtomUI.Controls.Themes;
+
+internal static class EmbeddingThemeConstants
+{
+    public const string TransparencyFallbackPart = "PART_TransparencyFallback";
+    public const string ContentPresenterPart = "PART_ContentPresenter";
+}

src/AtomUI.Controls/ScrollBar/Themes/ScrollViewerTheme.axaml

@@ -31,7 +31,7 @@
                                Orientation="Vertical"
                                Grid.Row="0"
                                Grid.Column="1" />
-                    <Panel x:Name="{x:Static atom:ScrollViewerThemeConstants.ScrollBarsSeparatorPart}"
+                    <Panel Name="{x:Static atom:ScrollViewerThemeConstants.ScrollBarsSeparatorPart}"
                            Grid.Row="1"
                            Grid.Column="1"
                            Background="{DynamicResource {x:Static atom:SharedTokenKey.ColorBgContainer}}"