fix: using DropShadowEffect in Launcher's popup container on Linux will get a wrong render result.

src/Resources/Styles.axaml

@@ -251,21 +251,44 @@
     <Setter Property="Foreground" Value="{DynamicResource Brush.FG1}"/>
     <Setter Property="Background" Value="{DynamicResource Brush.FlatButton.Background}"/>
     <Setter Property="VerticalContentAlignment" Value="Center"/>
-    <Setter Property="Effect">
-      <Setter.Value>
-        <DropShadowEffect BlurRadius="2" OffsetX="0" OffsetY="0" Color="Black" Opacity=".65"/>
-      </Setter.Value>
+    <Setter Property="Template">
+      <ControlTemplate>
+        <Grid>
+          <Border x:Name="PART_Border"
+                  Margin="2" 
+                  Background="{TemplateBinding Background}"
+                  BorderBrush="{TemplateBinding BorderBrush}"
+                  BorderThickness="{TemplateBinding BorderThickness}"
+                  CornerRadius="{TemplateBinding CornerRadius}"
+                  Effect="drop-shadow(0 0 2 #80000000)"/>
+
+          <ContentPresenter x:Name="PART_ContentPresenter"
+                            Margin="2"
+                            Background="Transparent"
+                            Padding="{TemplateBinding Padding}"
+                            Content="{TemplateBinding Content}"
+                            ContentTemplate="{TemplateBinding ContentTemplate}"
+                            HorizontalContentAlignment="Center"
+                            VerticalContentAlignment="Center"/>
+        </Grid>
+      </ControlTemplate>
     </Setter>
   </Style>
-  <Style Selector="Button.flat:pointerover /template/ ContentPresenter#PART_ContentPresenter">
+  <Style Selector="Button.flat:pointerover /template/ Border#PART_Border">
     <Setter Property="Background" Value="{DynamicResource Brush.FlatButton.BackgroundHovered}"/>
   </Style>
+  <Style Selector="Button.flat:pointerover /template/ ContentPresenter#PART_ContentPresenter">
+    <Setter Property="Background" Value="Transparent"/>
+  </Style>
   <Style Selector="Button.flat.primary">
     <Setter Property="Background" Value="{DynamicResource Brush.FlatButton.PrimaryBackground}"/>
   </Style>
-  <Style Selector="Button.flat.primary:pointerover /template/ ContentPresenter#PART_ContentPresenter">
+  <Style Selector="Button.flat.primary:pointerover /template/ Border#PART_Border">
     <Setter Property="Background" Value="{DynamicResource Brush.FlatButton.PrimaryBackgroundHovered}"/>
   </Style>
+  <Style Selector="Button.flat.primary:pointerover /template/ ContentPresenter#PART_ContentPresenter">
+    <Setter Property="Background" Value="Transparent"/>
+  </Style>
 
   <Style Selector="Border.launcher_pagetab">
     <Setter Property="Background" Value="Transparent"/>

src/Views/About.axaml

@@ -61,10 +61,7 @@
       <StackPanel Grid.Column="1" Orientation="Vertical" Margin="0,20,32,0">
         <StackPanel Height="48" Orientation="Horizontal">
           <TextBlock Classes="bold" Text="SourceGit" FontSize="32" />
-          <Border Margin="12,0,0,0" Height="20" CornerRadius="10" Background="{DynamicResource Brush.Accent1}">
-            <Border.Effect>
-              <DropShadowEffect OffsetX="0" OffsetY="0" BlurRadius="6" Color="Black" Opacity=".3"/>
-            </Border.Effect>
+          <Border Margin="12,0,0,0" Height="20" CornerRadius="10" Background="{DynamicResource Brush.Accent1}" Effect="drop-shadow(0 0 6 #40000000)">
             <TextBlock Classes="monospace" Margin="8,0" Text="{Binding Version}" FontSize="12" Foreground="White"/>
           </Border>
         </StackPanel>

src/Views/Launcher.axaml

@@ -239,22 +239,32 @@
     <v:LauncherBody Grid.Row="1" Background="{DynamicResource Brush.ToolBar}" Data="{Binding ActivePage.Data}"/>
 
     <!-- Popup container -->
-    <ContentControl Grid.Row="1" Margin="0,36,0,0" Content="{Binding ActivePage.Popup}" IsVisible="{Binding ActivePage.Popup, Converter={x:Static ObjectConverters.IsNotNull}}">
-      <ContentControl.DataTemplates>
-        <DataTemplate DataType="vm:Popup">
-          <Grid>
+    <Grid Grid.Row="1" Margin="0,36,0,0" IsVisible="{Binding ActivePage.Popup, Converter={x:Static ObjectConverters.IsNotNull}}">
       <Border Background="Transparent" PointerPressed="OnPopupCancelByClickMask"/>
 
       <Grid Width="500" HorizontalAlignment="Center" VerticalAlignment="Top">                
-              <Border Background="{DynamicResource Brush.Popup}" CornerRadius="0,0,4,4">
+        <ContentControl Content="{Binding ActivePage.Popup}" ClipToBounds="True">
+          <ContentControl.DataTemplates>
+            <DataTemplate DataType="vm:Popup">
+              <Border Margin="8,0,8,8"
+                      Background="{DynamicResource Brush.Popup}"
+                      BorderThickness="1,0,1,1"
+                      BorderBrush="{DynamicResource Brush.Border0}">
+                <Border.CornerRadius>
+                  <OnPlatform Default="0,0,4,4" Linux="0"/>
+                </Border.CornerRadius>
+
                 <Border.Effect>
-                  <DropShadowEffect BlurRadius="8" Color="Black" Opacity=".6" OffsetX="0" OffsetY="0"/>
+                  <OnPlatform>
+                    <On Options="Windows, macOS">
+                      <DropShadowEffect BlurRadius="8" OffsetX="0" OffsetY="0" Color="Black" Opacity=".5"/>
+                    </On>
+                  </OnPlatform>
                 </Border.Effect>
-              </Border>
                 
                 <StackPanel Margin="8" Orientation="Vertical">
                   <!-- Popup Widget -->
-                <ContentControl Margin="0,8"
+                  <ContentPresenter Margin="0,8"
                                     Content="{Binding View}"
                                     IsHitTestVisible="{Binding InProgress, Converter={x:Static BoolConverters.Not}}"/>
 
@@ -294,11 +304,12 @@
                                  Minimum="0" Maximum="100"/>
                   </StackPanel>
                 </StackPanel>
-            </Grid>
-          </Grid>
+              </Border>
             </DataTemplate>
           </ContentControl.DataTemplates>
         </ContentControl>
+      </Grid>
+    </Grid>
 
     <!-- Notification container -->
     <Grid Grid.Row="1" Width="360" Margin="0,36,0,0" HorizontalAlignment="Right" VerticalAlignment="Top">
@@ -307,11 +318,7 @@
           <ItemsControl.ItemTemplate>
             <DataTemplate DataType="m:Notification">
               <Grid Width="320" Margin="8">
-                <Border Background="{DynamicResource Brush.Window}" BorderBrush="{DynamicResource Brush.Border0}" BorderThickness="1" CornerRadius="4">
-                  <Border.Effect>
-                    <DropShadowEffect OffsetX="0" OffsetY="0" BlurRadius="8" Color="Black" Opacity=".4"/>
-                  </Border.Effect>
-                </Border>
+                <Border Background="{DynamicResource Brush.Window}" BorderBrush="{DynamicResource Brush.Border0}" BorderThickness="1" CornerRadius="4" Effect="drop-shadow(0 0 8 #40000000)"/>
 
                 <Grid Margin="8" RowDefinitions="26,Auto,Auto">
                   <StackPanel Grid.Row="0" Margin="8,0,0,0" Orientation="Horizontal" IsVisible="{Binding IsError}">
@@ -334,7 +341,7 @@
                            Text="{Binding Message}"/>
                   <Button Grid.Row="3"
                           Classes="flat primary"
-                          Height="25"
+                          Height="30"
                           Margin="4,0"
                           Command="{Binding #me.DataContext.(vm:Launcher).ActivePage.DismissNotification}"
                           CommandParameter="{Binding}"

src/Views/WorkingCopy.axaml

@@ -376,7 +376,7 @@
         <Button Grid.Column="4"
                 Classes="flat primary"
                 Content="{DynamicResource Text.WorkingCopy.Commit}"
-                Height="24"
+                Height="28"
                 Margin="8,0,0,0"
                 Padding="8,0"
                 Click="Commit"/>
@@ -384,7 +384,7 @@
         <Button Grid.Column="5"
                 Classes="flat"
                 Content="{DynamicResource Text.WorkingCopy.CommitAndPush}"
-                Height="24"
+                Height="28"
                 Margin="8,0,0,0"
                 Padding="8,0"
                 Click="CommitWithPush">