fix: unify window button sizes and use per-style caption icons

src/ManagedDrive.App/MainWindow.xaml

@@ -134,19 +134,19 @@
                             Click="MinimizeButton_Click"
                             ToolTip="{DynamicResource Tip.Minimize}"
                             AutomationProperties.Name="{DynamicResource Tip.Minimize}">
-                        <TextBlock Style="{StaticResource IconText}" Text="&#xE921;" FontSize="12"/>
+                        <TextBlock Style="{StaticResource MinimizeIconText}"/>
                     </Button>
                     <Button x:Name="MaximizeBtn" Style="{StaticResource IconButton}"
                             Click="MaximizeButton_Click"
                             ToolTip="{DynamicResource Tip.MaximizeRestore}"
                             AutomationProperties.Name="{DynamicResource Tip.MaximizeRestore}">
-                        <TextBlock x:Name="MaximizeIcon" Style="{StaticResource IconText}" Text="&#xE922;" FontSize="12"/>
+                        <TextBlock Style="{StaticResource MaximizeIconText}"/>
                     </Button>
                     <Button Style="{StaticResource CloseIconButton}"
                             Click="CloseButton_Click"
                             ToolTip="{DynamicResource Tip.HideToTray}"
                             AutomationProperties.Name="{DynamicResource Tip.HideToTray}">
-                        <TextBlock Style="{StaticResource IconText}" Text="&#xE8BB;"/>
+                        <TextBlock Style="{StaticResource CloseIconText}"/>
                     </Button>
         </StackPanel>
 

src/ManagedDrive.App/MainWindow.xaml.cs

@@ -16,8 +16,6 @@ public MainWindow(MainViewModel viewModel)
         InitializeComponent();
         DataContext = viewModel;
         WindowMaximizeHelper.HookMaximizeBehavior(this);
-        StateChanged += (_, _) => UpdateMaximizeIcon();
-        UpdateMaximizeIcon();
     }
 
     private void CloseButton_Click(object sender, RoutedEventArgs e) => Close();
@@ -27,14 +25,6 @@ public MainWindow(MainViewModel viewModel)
     private void MaximizeButton_Click(object sender, RoutedEventArgs e) =>
         WindowState = WindowState == WindowState.Maximized ? WindowState.Normal : WindowState.Maximized;
 
-    /// <summary>
-    /// Swaps the caption button's glyph between "maximize" and "restore" to match the current
-    /// <see cref="Window.WindowState"/>, since it toggles between the two rather than having
-    /// separate buttons for each.
-    /// </summary>
-    private void UpdateMaximizeIcon() =>
-        MaximizeIcon.Text = WindowState == WindowState.Maximized ? "" : "";
-
     /// <summary>
     /// Keeps the selected disk in view: a clicked notification can select one that is scrolled away.
     /// </summary>

src/ManagedDrive.App/Themes/AppTheme.xaml

@@ -99,6 +99,38 @@
     <SolidColorBrush x:Key="AppCloseHover" Color="#C42B1C"/>
     <SolidColorBrush x:Key="AppClosePressed" Color="#A02317"/>
 
+    <!-- Window button icons. Glyph and colour come from the current style (WindowGlyph* in AppStyle.{X}.xaml,
+         WindowIcon* in its palette), so each style draws its own set. -->
+    <Style x:Key="MinimizeIconText" TargetType="TextBlock" BasedOn="{StaticResource IconText}">
+        <Setter Property="Text" Value="{DynamicResource WindowGlyphMinimize}"/>
+        <Setter Property="Foreground" Value="{DynamicResource WindowIconMinimize}"/>
+    </Style>
+
+    <!-- The button toggles between maximize and restore, so the glyph follows the window state. -->
+    <Style x:Key="MaximizeIconText" TargetType="TextBlock" BasedOn="{StaticResource IconText}">
+        <Setter Property="Text" Value="{DynamicResource WindowGlyphMaximize}"/>
+        <Setter Property="Foreground" Value="{DynamicResource WindowIconMaximize}"/>
+        <Style.Triggers>
+            <DataTrigger Binding="{Binding WindowState, RelativeSource={RelativeSource AncestorType=Window}}" Value="Maximized">
+                <Setter Property="Text" Value="{DynamicResource WindowGlyphRestore}"/>
+            </DataTrigger>
+        </Style.Triggers>
+    </Style>
+
+    <!-- An explicit Foreground beats the button's own, so the white glyph of CloseIconButton's red hover is set here. -->
+    <Style x:Key="CloseIconText" TargetType="TextBlock" BasedOn="{StaticResource IconText}">
+        <Setter Property="Text" Value="{DynamicResource WindowGlyphClose}"/>
+        <Setter Property="Foreground" Value="{DynamicResource WindowIconClose}"/>
+        <Style.Triggers>
+            <DataTrigger Binding="{Binding IsMouseOver, RelativeSource={RelativeSource AncestorType=Button}}" Value="True">
+                <Setter Property="Foreground" Value="White"/>
+            </DataTrigger>
+            <DataTrigger Binding="{Binding IsPressed, RelativeSource={RelativeSource AncestorType=Button}}" Value="True">
+                <Setter Property="Foreground" Value="White"/>
+            </DataTrigger>
+        </Style.Triggers>
+    </Style>
+
     <Style x:Key="CloseIconButton" TargetType="Button" BasedOn="{StaticResource IconButton}">
         <!-- Style triggers beat the template's, so these replace the grey hover of the base style. -->
         <Style.Triggers>
@@ -133,15 +165,15 @@
                         <DockPanel>
                             <Border DockPanel.Dock="Top"
                                     Background="{DynamicResource AppBarBackground}"
-                                    Height="40"
+                                    Height="48"
                                     Padding="12,0,4,0">
                                 <DockPanel>
                                     <Button DockPanel.Dock="Right"
                                             Style="{StaticResource CloseIconButton}"
                                             Command="{x:Static views:DialogWindowBase.CloseDialogCommand}"
                                             WindowChrome.IsHitTestVisibleInChrome="True"
                                             ToolTip="{DynamicResource Tip.CloseDialog}">
-                                        <TextBlock Style="{StaticResource IconText}" Text="&#xE8BB;"/>
+                                        <TextBlock Style="{StaticResource CloseIconText}"/>
                                     </Button>
                                     <TextBlock VerticalAlignment="Center"
                                                FontSize="13" FontWeight="Medium"

src/ManagedDrive.App/Themes/Styles/AppStyle.A.xaml

@@ -1,5 +1,6 @@
 <ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
                     xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+                    xmlns:sys="clr-namespace:System;assembly=mscorlib"
                     xmlns:infra="clr-namespace:ManagedDrive.App.Infrastructure"
                     xmlns:controls="clr-namespace:ManagedDrive.App.Controls">
 
@@ -15,6 +16,14 @@
     <Thickness x:Key="DiskCardWarningPadding">15</Thickness>
     <Thickness x:Key="DiskCardOverlayMargin">-17</Thickness>
 
+    <!-- Window button glyphs (Segoe Fluent Icons), read by the MinimizeIconText/MaximizeIconText/CloseIconText styles in
+         AppTheme.xaml. Style A and C use the thin Windows caption glyphs; style B overrides them with the rounder ones
+         that match its tool icons. -->
+    <sys:String x:Key="WindowGlyphMinimize">&#xE921;</sys:String>
+    <sys:String x:Key="WindowGlyphMaximize">&#xE922;</sys:String>
+    <sys:String x:Key="WindowGlyphRestore">&#xE923;</sys:String>
+    <sys:String x:Key="WindowGlyphClose">&#xE8BB;</sys:String>
+
     <BooleanToVisibilityConverter x:Key="BoolToVis"/>
     <infra:PercentToGridLengthConverter x:Key="PercentToGridLengthConverter"/>
     <infra:IsFirstItemConverter x:Key="IsFirstItemConverter"/>

src/ManagedDrive.App/Themes/Styles/AppStyle.B.Colors.Dark.xaml

@@ -31,4 +31,9 @@
     <SolidColorBrush x:Key="ToolIconAbout" Color="#FF3CC4DD"/>
     <SolidColorBrush x:Key="ToolIconExit" Color="#FFFF6B6B"/>
 
+    <!-- Window button icons (minimize, maximize/restore, close). Every style palette must define these. -->
+    <SolidColorBrush x:Key="WindowIconMinimize" Color="#FFF5B83D"/>
+    <SolidColorBrush x:Key="WindowIconMaximize" Color="#FF34D399"/>
+    <SolidColorBrush x:Key="WindowIconClose" Color="#FFFF6B6B"/>
+
 </ResourceDictionary>

src/ManagedDrive.App/Themes/Styles/AppStyle.B.Colors.Light.xaml

@@ -31,4 +31,9 @@
     <SolidColorBrush x:Key="ToolIconAbout" Color="#FF0C93B0"/>
     <SolidColorBrush x:Key="ToolIconExit" Color="#FFD93838"/>
 
+    <!-- Window button icons (minimize, maximize/restore, close). Every style palette must define these. -->
+    <SolidColorBrush x:Key="WindowIconMinimize" Color="#FFD99100"/>
+    <SolidColorBrush x:Key="WindowIconMaximize" Color="#FF16A34A"/>
+    <SolidColorBrush x:Key="WindowIconClose" Color="#FFD93838"/>
+
 </ResourceDictionary>

src/ManagedDrive.App/Themes/Styles/AppStyle.B.xaml

@@ -1,5 +1,6 @@
 <ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
                     xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+                    xmlns:sys="clr-namespace:System;assembly=mscorlib"
                     xmlns:controls="clr-namespace:ManagedDrive.App.Controls">
 
     <!-- Style B (dashboard): starts from style A. The tool buttons move into a left sidebar, cards are raised panels
@@ -20,6 +21,13 @@
     <CornerRadius x:Key="SectionCornerRadius">10</CornerRadius>
     <CornerRadius x:Key="PopupCornerRadius">8</CornerRadius>
 
+    <!-- Window button glyphs: the rounder Remove / FullScreen / BackToWindow / Cancel icons, the same family as the
+         coloured tool icons (colours: WindowIcon* in the palette). -->
+    <sys:String x:Key="WindowGlyphMinimize">&#xE738;</sys:String>
+    <sys:String x:Key="WindowGlyphMaximize">&#xE740;</sys:String>
+    <sys:String x:Key="WindowGlyphRestore">&#xE73F;</sys:String>
+    <sys:String x:Key="WindowGlyphClose">&#xE711;</sys:String>
+
     <Style x:Key="SidebarStyle" TargetType="Border">
         <Setter Property="Grid.Column" Value="0"/>
         <Setter Property="Grid.RowSpan" Value="3"/>

src/ManagedDrive.App/Themes/Styles/AppStyle.C.Colors.Dark.xaml

@@ -29,4 +29,9 @@
     <SolidColorBrush x:Key="ToolIconAbout" Color="#FFEDEDED"/>
     <SolidColorBrush x:Key="ToolIconExit" Color="#FFEDEDED"/>
 
+    <!-- Window button icons: monochrome too. -->
+    <SolidColorBrush x:Key="WindowIconMinimize" Color="#FFEDEDED"/>
+    <SolidColorBrush x:Key="WindowIconMaximize" Color="#FFEDEDED"/>
+    <SolidColorBrush x:Key="WindowIconClose" Color="#FFEDEDED"/>
+
 </ResourceDictionary>

src/ManagedDrive.App/Themes/Styles/AppStyle.C.Colors.Light.xaml

@@ -29,4 +29,9 @@
     <SolidColorBrush x:Key="ToolIconAbout" Color="#FF1C1C1C"/>
     <SolidColorBrush x:Key="ToolIconExit" Color="#FF1C1C1C"/>
 
+    <!-- Window button icons: monochrome too. -->
+    <SolidColorBrush x:Key="WindowIconMinimize" Color="#FF1C1C1C"/>
+    <SolidColorBrush x:Key="WindowIconMaximize" Color="#FF1C1C1C"/>
+    <SolidColorBrush x:Key="WindowIconClose" Color="#FF1C1C1C"/>
+
 </ResourceDictionary>

src/ManagedDrive.App/Views/DialogWindowBase.cs

@@ -27,7 +27,7 @@ protected DialogWindowBase()
     {
         WindowChrome.SetWindowChrome(this, new()
         {
-            CaptionHeight = 40,
+            CaptionHeight = 48,
             ResizeBorderThickness = new(0),
             GlassFrameThickness = new(0),
             NonClientFrameEdges = NonClientFrameEdges.None,

src/ManagedDrive.App/Views/DiskContentDialog.xaml

@@ -5,7 +5,7 @@
         xmlns:helpers="clr-namespace:ManagedDrive.App.Helpers"
         Style="{DynamicResource DialogWindowStyle}"
         Title="{DynamicResource DiskContent.Title}"
-        Width="480" Height="480"
+        Width="480" Height="488"
         MinWidth="360" MinHeight="320"
         ResizeMode="CanResize"
         WindowStartupLocation="CenterOwner">

src/ManagedDrive.App/Views/DiskContentDialog.xaml.cs

@@ -51,7 +51,7 @@ public DiskContentDialog(DiskViewModel target)
         // fixed-size), so this window alone can be resized by dragging its edges.
         WindowChrome.SetWindowChrome(this, new()
         {
-            CaptionHeight = 40,
+            CaptionHeight = 48,
             ResizeBorderThickness = new(6),
             GlassFrameThickness = new(0),
             NonClientFrameEdges = NonClientFrameEdges.None,

src/ManagedDrive.App/Views/SpaceUsageDialog.xaml.cs

@@ -91,7 +91,7 @@ public SpaceUsageDialog(DiskViewModel target, int listSize, Action<int> listSize
         // Same as the disk-content dialog: the one other dialog that can be resized and maximized.
         WindowChrome.SetWindowChrome(this, new()
         {
-            CaptionHeight = 40,
+            CaptionHeight = 48,
             ResizeBorderThickness = new(6),
             GlassFrameThickness = new(0),
             NonClientFrameEdges = NonClientFrameEdges.None,

tests/ManagedDrive.Tests/Themes/PaletteKeysTests.cs

@@ -23,6 +23,18 @@ public sealed class PaletteKeysTests
     private static readonly string[] SidebarIconKeys =
         { "ToolIconNew", "ToolIconImport", "ToolIconRestore", "ToolIconSettings", "ToolIconAbout", "ToolIconExit" };
 
+    /// <summary>
+    /// Brush keys read by the minimize, maximize and close icon styles.
+    /// </summary>
+    private static readonly string[] WindowIconKeys =
+        { "WindowIconMinimize", "WindowIconMaximize", "WindowIconClose" };
+
+    /// <summary>
+    /// Glyph keys read by the minimize, maximize and close icon styles.
+    /// </summary>
+    private static readonly string[] WindowGlyphKeys =
+        { "WindowGlyphMinimize", "WindowGlyphMaximize", "WindowGlyphRestore", "WindowGlyphClose" };
+
     /// <summary>
     /// Verifies that the keys the cards use exist in the theme palette alone and in the theme palette
     /// with a style palette merged over it, for every style and theme.
@@ -68,6 +80,44 @@ public void StyleB_DefinesEverySidebarIconKey(string theme)
         Assert.Empty(missing);
     }
 
+    /// <summary>
+    /// Verifies that styles B and C define a colour for each window button icon in both themes.
+    /// </summary>
+    [Theory]
+    [InlineData("B", "Light")]
+    [InlineData("B", "Dark")]
+    [InlineData("C", "Light")]
+    [InlineData("C", "Dark")]
+    public void StylePalette_DefinesEveryWindowIconKey(string style, string theme)
+    {
+        // Arrange
+        var keys = KeysOf($"Styles/AppStyle.{style}.Colors.{theme}.xaml");
+
+        // Act
+        var missing = WindowIconKeys.Where(k => !keys.Contains(k)).ToList();
+
+        // Assert
+        Assert.Empty(missing);
+    }
+
+    /// <summary>
+    /// Verifies that the base style (inherited by C) and style B each define every window button glyph.
+    /// </summary>
+    [Theory]
+    [InlineData("A")]
+    [InlineData("B")]
+    public void Style_DefinesEveryWindowGlyphKey(string style)
+    {
+        // Arrange
+        var keys = KeysOf($"Styles/AppStyle.{style}.xaml");
+
+        // Act
+        var missing = WindowGlyphKeys.Where(k => !keys.Contains(k)).ToList();
+
+        // Assert
+        Assert.Empty(missing);
+    }
+
     /// <summary>
     /// Verifies that a light palette and its dark counterpart define the same keys, so a theme switch
     /// never drops a brush.