Author manual Light/Dark brushes for the surfaces ILSpy paints itself

Simple theme ships no Dark resource dictionary, so flipping
RequestedThemeVariant alone is a no-op against any surface whose
brushes are hardcoded or pulled from a Simple key. We can't swap
themes (Simple is the deliberate visual identity), but we can layer
our own ThemeDictionaries on top so the surfaces ILSpy owns directly
respond to View > Theme.

Introduce a single block of Light / Dark brush pairs under
Application.Resources.ThemeDictionaries (App.axaml), then route the
hardcoded brushes in the editor view, the toolbar, the zoom overlay,
and tooltips through DynamicResource lookups against those keys.

Surfaces wired:
- Decompiler text view background and wait-adorner overlay.
- Main toolbar background, bottom border, separator hairlines,
  combobox border, and the disabled-button content fills.
- Zoom-buttons overlay background and border.
- Tooltips (background, foreground, border) via a Style selector
  since Simple paints them via hardcoded setters that don't expose
  a brush key.

Simple-themed chrome (menu, tree, scrollbars, status bar, dock
splitters) remains Light in both variants. That's partial dark mode
by design -- covering it requires either swapping to Fluent (which
costs the Simple visual identity, and a separate test showed the
chrome regressing under Fluent) or redeclaring every Simple resource
key per variant, which is a much larger effort. Follow-ups will
extend coverage one surface at a time.

Light values match what each file shipped (no visible diff in the
default theme). Dark values follow the VS-style palette:
  editor       #1E1E1E
  toolbar      #2D2D30  border  #3F3F46
  tooltip      #252526  border  #3F3F46  foreground #DCDCDC
  zoom overlay #E01E1E1E with translucent gray border

Assisted-by: Claude:claude-opus-4-7:Claude Code

ILSpy/App.axaml

@@ -19,6 +19,46 @@
              <!-- "Default" ThemeVariant follows system theme variant. "Dark" or "Light" are other available options. -->
 
     <Application.Resources>
+        <ResourceDictionary>
+            <ResourceDictionary.ThemeDictionaries>
+                <!-- Light / Dark variant brushes for the surfaces ILSpy paints directly
+                     (the editor canvas and the toolbar chrome). The Simple theme itself
+                     ships no Dark resource dictionary, so chrome painted by Simple (menu,
+                     scrollbars, tree, status bar) stays Light regardless of the user's
+                     theme choice. Intentional, partial dark mode targeting only the
+                     surfaces a reader spends most time looking at. -->
+                <ResourceDictionary x:Key="Light">
+                    <SolidColorBrush x:Key="ILSpy.EditorBackground" Color="#FFFFE1" />
+                    <SolidColorBrush x:Key="ILSpy.EditorWaitAdornerBackground" Color="#80FFFFFF" />
+                    <SolidColorBrush x:Key="ILSpy.ToolbarBackground" Color="White" />
+                    <SolidColorBrush x:Key="ILSpy.ToolbarBorder" Color="#FFA9B0B7" />
+                    <SolidColorBrush x:Key="ILSpy.ToolbarSeparator" Color="#FFC8CDD3" />
+                    <SolidColorBrush x:Key="ILSpy.ToolbarComboBoxBorder" Color="#FFCCCEDB" />
+                    <SolidColorBrush x:Key="ILSpy.ToolbarDisabledFill" Color="#22000000" />
+                    <SolidColorBrush x:Key="ILSpy.ToolbarDisabledBorder" Color="#33000000" />
+                    <SolidColorBrush x:Key="ILSpy.ZoomButtonsBackground" Color="#E0FFFFE1" />
+                    <SolidColorBrush x:Key="ILSpy.ZoomButtonsBorder" Color="#80808080" />
+                    <SolidColorBrush x:Key="ILSpy.TooltipBackground" Color="#FFFFE1" />
+                    <SolidColorBrush x:Key="ILSpy.TooltipForeground" Color="Black" />
+                    <SolidColorBrush x:Key="ILSpy.TooltipBorder" Color="#FF767676" />
+                </ResourceDictionary>
+                <ResourceDictionary x:Key="Dark">
+                    <SolidColorBrush x:Key="ILSpy.EditorBackground" Color="#1E1E1E" />
+                    <SolidColorBrush x:Key="ILSpy.EditorWaitAdornerBackground" Color="#A0000000" />
+                    <SolidColorBrush x:Key="ILSpy.ToolbarBackground" Color="#2D2D30" />
+                    <SolidColorBrush x:Key="ILSpy.ToolbarBorder" Color="#3F3F46" />
+                    <SolidColorBrush x:Key="ILSpy.ToolbarSeparator" Color="#3F3F46" />
+                    <SolidColorBrush x:Key="ILSpy.ToolbarComboBoxBorder" Color="#3F3F46" />
+                    <SolidColorBrush x:Key="ILSpy.ToolbarDisabledFill" Color="#22FFFFFF" />
+                    <SolidColorBrush x:Key="ILSpy.ToolbarDisabledBorder" Color="#33FFFFFF" />
+                    <SolidColorBrush x:Key="ILSpy.ZoomButtonsBackground" Color="#E01E1E1E" />
+                    <SolidColorBrush x:Key="ILSpy.ZoomButtonsBorder" Color="#80A0A0A0" />
+                    <SolidColorBrush x:Key="ILSpy.TooltipBackground" Color="#252526" />
+                    <SolidColorBrush x:Key="ILSpy.TooltipForeground" Color="#DCDCDC" />
+                    <SolidColorBrush x:Key="ILSpy.TooltipBorder" Color="#3F3F46" />
+                </ResourceDictionary>
+            </ResourceDictionary.ThemeDictionaries>
+
             <!-- Every dockable owns its view (IDockableViewOwner): the dock chrome must render one
                  view per dockable identity, not one per slot, or two panes sharing a ToolDock slot
                  (e.g. Analyzer + Debug Steps both Bottom-aligned) render each other's content. This
@@ -46,6 +86,7 @@
                  translucent accent matches MainToolBar.axaml's button hover treatment. -->
             <SolidColorBrush x:Key="DataGridColumnHeaderHoveredBackgroundBrush" Color="#330078D7" />
             <SolidColorBrush x:Key="DataGridColumnHeaderPressedBackgroundBrush" Color="#660078D7" />
+        </ResourceDictionary>
     </Application.Resources>
 
     <Application.DataTemplates>
@@ -67,6 +108,16 @@
             <Setter Property="(recycling:ControlRecyclingDataTemplate.ControlRecycling)" Value="{StaticResource ControlRecyclingKey}" />
         </Style>
 
+        <!-- Tooltips: Simple theme paints them with hardcoded fills that don't respond to
+             RequestedThemeVariant. Restyle ToolTip so background, foreground, and border
+             route through our ILSpy.Tooltip* brushes and swap with the active theme. -->
+        <Style Selector="ToolTip">
+            <Setter Property="Background" Value="{DynamicResource ILSpy.TooltipBackground}" />
+            <Setter Property="Foreground" Value="{DynamicResource ILSpy.TooltipForeground}" />
+            <Setter Property="BorderBrush" Value="{DynamicResource ILSpy.TooltipBorder}" />
+            <Setter Property="BorderThickness" Value="1" />
+        </Style>
+
         <!-- Suppress the column header's hover / pressed fill while the user is interacting
              with content INSIDE the header (e.g. typing into a per-column filter TextBox).
              Without this, clicking the TextBox briefly flashes the header background blue —

ILSpy/TextView/DecompilerTextView.axaml

@@ -17,11 +17,11 @@
 		<textView:DecompilerTextEditor Name="Editor"
 		                               IsReadOnly="True"
 		                               ShowLineNumbers="True"
-		                               Background="#FFFFE1"
+		                               Background="{DynamicResource ILSpy.EditorBackground}"
 		                               FontFamily="Consolas, Menlo, Monospace"
 		                               FontSize="13" />
 		<Border Name="WaitAdorner"
-		        Background="#80FFFFFF"
+		        Background="{DynamicResource ILSpy.EditorWaitAdornerBackground}"
 		        IsVisible="{Binding IsDecompiling}">
 			<Grid ColumnDefinitions="*,Auto,*">
 				<StackPanel Grid.Column="1"

ILSpy/TextView/ZoomButtons.axaml

@@ -3,7 +3,9 @@
              x:Class="ILSpy.TextView.ZoomButtons"
              HorizontalAlignment="Right" VerticalAlignment="Bottom"
              Margin="0,0,12,12">
-	<Border Background="#E0FFFFE1" BorderBrush="#80808080" BorderThickness="1"
+	<Border Background="{DynamicResource ILSpy.ZoomButtonsBackground}"
+	        BorderBrush="{DynamicResource ILSpy.ZoomButtonsBorder}"
+	        BorderThickness="1"
 	        CornerRadius="3" Padding="2">
 		<StackPanel Orientation="Horizontal" Spacing="2">
 			<Button Name="MinusButton" Content="&#8722;" Width="22" Height="22"

ILSpy/Views/MainToolBar.axaml

@@ -97,8 +97,8 @@
 			<Setter Property="Cursor" Value="Arrow" />
 		</Style>
 		<Style Selector="StackPanel#ToolbarRoot > Button:disabled /template/ ContentPresenter, StackPanel#ToolbarRoot > ToggleButton:disabled /template/ ContentPresenter">
-			<Setter Property="Background" Value="#22000000" />
+			<Setter Property="Background" Value="{DynamicResource ILSpy.ToolbarDisabledFill}" />
-			<Setter Property="BorderBrush" Value="#33000000" />
+			<Setter Property="BorderBrush" Value="{DynamicResource ILSpy.ToolbarDisabledBorder}" />
 		</Style>
 		<!-- Default Fluent SplitButton paints both halves with an opaque dark fill on press
 		     (looks black against our white toolbar). Replace with the toolbar accent palette
@@ -125,7 +125,7 @@
 			<Setter Property="Width" Value="1" />
 			<Setter Property="Height" Value="18" />
 			<Setter Property="Margin" Value="4,3" />
-			<Setter Property="Background" Value="#FFC8CDD3" />
+			<Setter Property="Background" Value="{DynamicResource ILSpy.ToolbarSeparator}" />
 		</Style>
 
 		<!-- Keep the combos flush with the buttons; soften the default border so it sits
@@ -136,7 +136,7 @@
 			<Setter Property="MinHeight" Value="22" />
 			<Setter Property="Padding" Value="6,1" />
 			<Setter Property="VerticalContentAlignment" Value="Center" />
-			<Setter Property="BorderBrush" Value="#FFCCCEDB" />
+			<Setter Property="BorderBrush" Value="{DynamicResource ILSpy.ToolbarComboBoxBorder}" />
 		</Style>
 		<!-- The Simple theme's ComboBox template (this project uses Avalonia.Themes.Simple,
 		     not Fluent) places a separate ToggleButton named "toggle" in the chevron column
@@ -168,9 +168,9 @@
 		</Style>
 	</UserControl.Styles>
 
-	<Border BorderThickness="0,0,0,1" BorderBrush="#FFA9B0B7"
+	<Border BorderThickness="0,0,0,1" BorderBrush="{DynamicResource ILSpy.ToolbarBorder}"
 	        MinHeight="29" Padding="3"
-	        Background="White">
+	        Background="{DynamicResource ILSpy.ToolbarBackground}">
 		<StackPanel Name="ToolbarRoot" Orientation="Horizontal">
 			<!-- Navigation: Back / Forward as web-browser-style split buttons. The primary half
 			     navigates one step; the chevron drops a menu of recent history entries built on