Fix ui (#9789)

v2rayN/v2rayN.Desktop/App.axaml

@@ -22,6 +22,14 @@
         <StyleInclude Source="Assets/GlobalStyles.axaml" />
         <StyleInclude Source="avares://Semi.Avalonia.DataGrid/Index.axaml" />
         <dialogHost:DialogHostStyles />
+
+        <Style Selector="dialogHost|DialogHost">
+            <Setter Property="OverlayBackground" Value="{DynamicResource SemiColorOverlayBackground}" />
+            <Setter Property="Background" Value="{DynamicResource SemiColorFill0}" />
+
+            <Setter Property="dialogHost:DialogHostStyle.BoxShadow" Value="{DynamicResource SemiShadowElevated}" />
+            <Setter Property="dialogHost:DialogHostStyle.CornerRadius" Value="6" />
+        </Style>
     </Application.Styles>
 
     <TrayIcon.Icons>

v2rayN/v2rayN.Desktop/Views/MainWindow.axaml

@@ -18,10 +18,7 @@
     ShowInTaskbar="True"
     WindowStartupLocation="CenterScreen"
     mc:Ignorable="d">
-    <dialogHost:DialogHost
-        Background="Gray"
-        CloseOnClickAway="True"
-        DisableOpeningAnimation="True">
+    <dialogHost:DialogHost CloseOnClickAway="True" DisableOpeningAnimation="True">
         <DockPanel>
             <DockPanel Margin="{StaticResource Margin8}" DockPanel.Dock="Top">
                 <ContentControl x:Name="conTheme" DockPanel.Dock="Right" />

v2rayN/v2rayN.Desktop/Views/SubSettingWindow.axaml

@@ -17,7 +17,6 @@
     WindowStartupLocation="CenterScreen"
     mc:Ignorable="d">
     <dialogHost:DialogHost
-        Background="Gray"
         CloseOnClickAway="True"
         DisableOpeningAnimation="True"
         Identifier="dialogHostSub">