added interface themes

CursorLang/App.xaml

@@ -3,6 +3,10 @@
              xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
              ShutdownMode="OnMainWindowClose">
     <Application.Resources>
-
+        <ResourceDictionary>
+            <ResourceDictionary.MergedDictionaries>
+                <ResourceDictionary Source="Themes/Controls.xaml" />
+            </ResourceDictionary.MergedDictionaries>
+        </ResourceDictionary>
     </Application.Resources>
 </Application>

CursorLang/App.xaml.cs

@@ -22,6 +22,8 @@ public partial class App : Application
         ConfigureServices(services);
         _services = services.BuildServiceProvider();
 
+        _services.GetRequiredService<ThemeService>();
+
         MainWindow = _services.GetRequiredService<MainWindow>();
         MainWindow.Show();
 
@@ -43,6 +45,9 @@ public partial class App : Application
         services.AddSingleton<SettingsService>();
         services.AddSingleton(provider => provider.GetRequiredService<SettingsService>().Load());
 
+        services.AddSingleton<ThemeService>();
+        services.AddSingleton<IThemeService>(provider => provider.GetRequiredService<ThemeService>());
+
         services.AddSingleton<ILocalizationService, LocalizationService>();
         services.AddSingleton<IKeyboardLayoutService, KeyboardLayoutService>();
         services.AddSingleton<ILayoutPopupService, LayoutPopupService>();

CursorLang/Interop/WindowThemeNative.cs

@@ -0,0 +1,30 @@
+using System.Runtime.InteropServices;
+
+namespace CursorLang.Interop;
+
+/// <summary>
+/// Оформление рамки окна средствами системы: заголовок рисует Windows,
+/// и в тёмной теме его нужно переключать отдельно от содержимого окна.
+/// </summary>
+internal static class WindowThemeNative
+{
+    [DllImport("dwmapi.dll")]
+    private static extern int DwmSetWindowAttribute(IntPtr hWnd, int attribute, ref int value, int size);
+
+    private const int DWMWA_USE_IMMERSIVE_DARK_MODE = 20;
+
+    /// <summary>
+    /// Перекрашивает заголовок окна. На сборках Windows 10 до 2004 атрибут
+    /// не поддерживается — заголовок просто останется светлым.
+    /// </summary>
+    internal static void SetDarkTitleBar(IntPtr hWnd, bool isDark)
+    {
+        if (hWnd == IntPtr.Zero)
+        {
+            return;
+        }
+
+        int value = isDark ? 1 : 0;
+        DwmSetWindowAttribute(hWnd, DWMWA_USE_IMMERSIVE_DARK_MODE, ref value, sizeof(int));
+    }
+}

CursorLang/Models/AppSettings.cs

@@ -14,6 +14,10 @@ public sealed partial class AppSettings : ObservableObject
     [ObservableProperty]
     private string _language = "en";
 
+    /// <summary>Оформление окна настроек.</summary>
+    [ObservableProperty]
+    private AppTheme _theme = AppTheme.System;
+
     [ObservableProperty]
     private PopupPlacementMode _placementMode = PopupPlacementMode.AtCursor;
 

CursorLang/Models/AppTheme.cs

@@ -0,0 +1,12 @@
+namespace CursorLang.Models;
+
+/// <summary>
+/// Оформление окна настроек. По умолчанию приложение следует теме Windows,
+/// но пользователь может закрепить светлую или тёмную.
+/// </summary>
+public enum AppTheme
+{
+    System,
+    Light,
+    Dark
+}

CursorLang/Resources/Strings.resx

@@ -67,6 +67,18 @@
   <data name="LanguageLabel" xml:space="preserve">
     <value>Interface language</value>
   </data>
+  <data name="ThemeLabel" xml:space="preserve">
+    <value>Theme</value>
+  </data>
+  <data name="AppTheme_System" xml:space="preserve">
+    <value>Same as Windows</value>
+  </data>
+  <data name="AppTheme_Light" xml:space="preserve">
+    <value>Light</value>
+  </data>
+  <data name="AppTheme_Dark" xml:space="preserve">
+    <value>Dark</value>
+  </data>
   <data name="SectionPlacement" xml:space="preserve">
     <value>Placement</value>
   </data>

CursorLang/Resources/Strings.ru.resx

@@ -67,6 +67,18 @@
   <data name="LanguageLabel" xml:space="preserve">
     <value>Язык интерфейса</value>
   </data>
+  <data name="ThemeLabel" xml:space="preserve">
+    <value>Тема</value>
+  </data>
+  <data name="AppTheme_System" xml:space="preserve">
+    <value>Как в Windows</value>
+  </data>
+  <data name="AppTheme_Light" xml:space="preserve">
+    <value>Светлая</value>
+  </data>
+  <data name="AppTheme_Dark" xml:space="preserve">
+    <value>Тёмная</value>
+  </data>
   <data name="SectionPlacement" xml:space="preserve">
     <value>Расположение</value>
   </data>

CursorLang/Services/IThemeService.cs

@@ -0,0 +1,19 @@
+using System.Windows;
+using CursorLang.Models;
+
+namespace CursorLang.Services;
+
+/// <summary>
+/// Применяет светлое или тёмное оформление к окнам приложения.
+/// </summary>
+public interface IThemeService
+{
+    /// <summary>Тема, действующая сейчас.</summary>
+    AppTheme CurrentTheme { get; }
+
+    /// <summary>
+    /// Подключает окно к смене темы: заголовок окна рисует Windows,
+    /// и его цвет приходится переключать для каждого окна отдельно.
+    /// </summary>
+    void Register(Window window);
+}

CursorLang/Services/SettingsService.cs

@@ -90,12 +90,10 @@ public sealed class SettingsService : IDisposable
         }
         catch (Exception e) when (e is IOException or UnauthorizedAccessException or JsonException)
         {
-            // Испорченный файл не должен мешать запуску: начнём с умолчаний
             return null;
         }
     }
 
-    // Язык по умолчанию берём системный, если он поддерживается
     private static AppSettings CreateDefault()
     {
         string uiLanguage = System.Globalization.CultureInfo.CurrentUICulture.TwoLetterISOLanguageName;

CursorLang/Services/ThemeService.cs

@@ -0,0 +1,144 @@
+using System.ComponentModel;
+using System.Windows;
+using System.Windows.Interop;
+using CursorLang.Interop;
+using CursorLang.Models;
+using Microsoft.Win32;
+
+namespace CursorLang.Services;
+
+/// <summary>
+/// Держит в ресурсах приложения палитру выбранной темы и подменяет её
+/// при смене настройки — окна перекрашиваются без перезапуска.
+/// </summary>
+public sealed class ThemeService : IThemeService, IDisposable
+{
+    private const string PersonalizeKey =
+        @"Software\Microsoft\Windows\CurrentVersion\Themes\Personalize";
+
+    private readonly AppSettings _settings;
+    private readonly List<Window> _windows = [];
+    private ResourceDictionary? _palette;
+    private AppTheme _current;
+
+    public ThemeService(AppSettings settings)
+    {
+        _settings = settings;
+        _settings.PropertyChanged += OnSettingsChanged;
+        SystemEvents.UserPreferenceChanged += OnUserPreferenceChanged;
+        Apply();
+    }
+
+    /// <summary>Тема, которую видит пользователь: <c>System</c> здесь уже разрешён.</summary>
+    public AppTheme CurrentTheme => _current;
+
+    public void Register(Window window)
+    {
+        _windows.Add(window);
+        window.Closed += OnWindowClosed;
+
+        if (new WindowInteropHelper(window).Handle == IntPtr.Zero)
+        {
+            window.SourceInitialized += OnWindowSourceInitialized;
+            return;
+        }
+
+        ApplyTitleBar(window);
+    }
+
+    public void Dispose()
+    {
+        _settings.PropertyChanged -= OnSettingsChanged;
+        SystemEvents.UserPreferenceChanged -= OnUserPreferenceChanged;
+
+        foreach (Window window in _windows)
+        {
+            window.Closed -= OnWindowClosed;
+            window.SourceInitialized -= OnWindowSourceInitialized;
+        }
+
+        _windows.Clear();
+    }
+
+    /// <summary>Тема приложений в настройках Windows.</summary>
+    private static AppTheme DetectSystemTheme()
+    {
+        try
+        {
+            using RegistryKey? key = Registry.CurrentUser.OpenSubKey(PersonalizeKey);
+            return key?.GetValue("AppsUseLightTheme") is int light && light == 0
+                ? AppTheme.Dark
+                : AppTheme.Light;
+        }
+        catch (Exception e) when (e is System.Security.SecurityException or UnauthorizedAccessException)
+        {
+            return AppTheme.Light;
+        }
+    }
+
+    private void OnSettingsChanged(object? sender, PropertyChangedEventArgs e)
+    {
+        if (e.PropertyName == nameof(AppSettings.Theme))
+        {
+            Apply();
+        }
+    }
+
+    // Windows сообщает о смене оформления не из потока интерфейса
+    private void OnUserPreferenceChanged(object? sender, UserPreferenceChangedEventArgs e) =>
+        Application.Current?.Dispatcher.InvokeAsync(Apply);
+
+    private void Apply()
+    {
+        AppTheme theme = _settings.Theme == AppTheme.System ? DetectSystemTheme() : _settings.Theme;
+        if (_palette is not null && theme == _current)
+        {
+            return;
+        }
+
+        _current = theme;
+
+        var next = new ResourceDictionary
+        {
+            Source = new Uri($"pack://application:,,,/Themes/{theme}.xaml", UriKind.Absolute),
+        };
+
+        ICollection<ResourceDictionary> dictionaries = Application.Current.Resources.MergedDictionaries;
+        dictionaries.Add(next);
+
+        if (_palette is not null)
+        {
+            dictionaries.Remove(_palette);
+        }
+
+        _palette = next;
+
+        foreach (Window window in _windows)
+        {
+            ApplyTitleBar(window);
+        }
+    }
+
+    private void ApplyTitleBar(Window window) =>
+        WindowThemeNative.SetDarkTitleBar(
+            new WindowInteropHelper(window).Handle,
+            _current == AppTheme.Dark);
+
+    private void OnWindowSourceInitialized(object? sender, EventArgs e)
+    {
+        if (sender is Window window)
+        {
+            window.SourceInitialized -= OnWindowSourceInitialized;
+            ApplyTitleBar(window);
+        }
+    }
+
+    private void OnWindowClosed(object? sender, EventArgs e)
+    {
+        if (sender is Window window)
+        {
+            window.Closed -= OnWindowClosed;
+            _windows.Remove(window);
+        }
+    }
+}

CursorLang/Themes/Controls.xaml

@@ -0,0 +1,294 @@
+<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
+
+    <!-- ======================= GroupBox ======================= -->
+
+    <Style TargetType="GroupBox">
+        <Setter Property="Padding" Value="12" />
+        <Setter Property="Margin" Value="0,0,0,12" />
+        <Setter Property="Foreground" Value="{DynamicResource Theme.Foreground}" />
+        <Setter Property="Template">
+            <Setter.Value>
+                <ControlTemplate TargetType="GroupBox">
+                    <Grid>
+                        <Grid.RowDefinitions>
+                            <RowDefinition Height="Auto" />
+                            <RowDefinition Height="*" />
+                        </Grid.RowDefinitions>
+                        <ContentPresenter ContentSource="Header"
+                                          Margin="2,0,0,6"
+                                          TextBlock.FontWeight="SemiBold" />
+                        <Border Grid.Row="1"
+                                Background="{DynamicResource Theme.Surface}"
+                                BorderBrush="{DynamicResource Theme.ControlBorder}"
+                                BorderThickness="1"
+                                CornerRadius="6"
+                                Padding="{TemplateBinding Padding}"
+                                SnapsToDevicePixels="True">
+                            <ContentPresenter />
+                        </Border>
+                    </Grid>
+                </ControlTemplate>
+            </Setter.Value>
+        </Setter>
+    </Style>
+
+    <!-- ======================= ComboBox ======================= -->
+
+    <Style x:Key="ComboBoxToggleStyle" TargetType="ToggleButton">
+        <Setter Property="OverridesDefaultStyle" Value="True" />
+        <Setter Property="Focusable" Value="False" />
+        <Setter Property="IsTabStop" Value="False" />
+        <Setter Property="ClickMode" Value="Press" />
+        <Setter Property="Template">
+            <Setter.Value>
+                <ControlTemplate TargetType="ToggleButton">
+                    <Border x:Name="Border"
+                            Background="{DynamicResource Theme.ControlBackground}"
+                            BorderBrush="{DynamicResource Theme.ControlBorder}"
+                            BorderThickness="1"
+                            CornerRadius="4"
+                            SnapsToDevicePixels="True">
+                        <Path x:Name="Arrow"
+                              HorizontalAlignment="Right" VerticalAlignment="Center"
+                              Margin="0,0,10,0"
+                              Data="M0,0 L4,4 L8,0"
+                              Stroke="{DynamicResource Theme.SecondaryForeground}"
+                              StrokeThickness="1.4" />
+                    </Border>
+                    <ControlTemplate.Triggers>
+                        <Trigger Property="IsMouseOver" Value="True">
+                            <Setter TargetName="Border" Property="Background"
+                                    Value="{DynamicResource Theme.ControlHoverBackground}" />
+                        </Trigger>
+                        <Trigger Property="IsChecked" Value="True">
+                            <Setter TargetName="Border" Property="BorderBrush"
+                                    Value="{DynamicResource Theme.Accent}" />
+                            <Setter TargetName="Arrow" Property="Stroke"
+                                    Value="{DynamicResource Theme.Accent}" />
+                        </Trigger>
+                        <Trigger Property="IsEnabled" Value="False">
+                            <Setter TargetName="Border" Property="Opacity" Value="0.5" />
+                        </Trigger>
+                    </ControlTemplate.Triggers>
+                </ControlTemplate>
+            </Setter.Value>
+        </Setter>
+    </Style>
+
+    <Style TargetType="ComboBoxItem">
+        <Setter Property="Foreground" Value="{DynamicResource Theme.Foreground}" />
+        <Setter Property="Padding" Value="8,5" />
+        <Setter Property="Template">
+            <Setter.Value>
+                <ControlTemplate TargetType="ComboBoxItem">
+                    <Border x:Name="Border"
+                            Background="Transparent"
+                            CornerRadius="3"
+                            Margin="3,1"
+                            Padding="{TemplateBinding Padding}">
+                        <ContentPresenter />
+                    </Border>
+                    <ControlTemplate.Triggers>
+                        <Trigger Property="IsHighlighted" Value="True">
+                            <Setter TargetName="Border" Property="Background"
+                                    Value="{DynamicResource Theme.SelectionBackground}" />
+                        </Trigger>
+                        <Trigger Property="IsSelected" Value="True">
+                            <Setter TargetName="Border" Property="Background"
+                                    Value="{DynamicResource Theme.SelectionBackground}" />
+                        </Trigger>
+                    </ControlTemplate.Triggers>
+                </ControlTemplate>
+            </Setter.Value>
+        </Setter>
+    </Style>
+
+    <Style TargetType="ComboBox">
+        <Setter Property="VerticalAlignment" Value="Center" />
+        <Setter Property="Foreground" Value="{DynamicResource Theme.Foreground}" />
+        <!-- Правый отступ оставляет место под стрелку -->
+        <Setter Property="Padding" Value="9,5,28,5" />
+        <Setter Property="Template">
+            <Setter.Value>
+                <ControlTemplate TargetType="ComboBox">
+                    <Grid>
+                        <ToggleButton Style="{StaticResource ComboBoxToggleStyle}"
+                                      IsChecked="{Binding IsDropDownOpen, Mode=TwoWay,
+                                          RelativeSource={RelativeSource TemplatedParent}}" />
+                        <ContentPresenter Margin="{TemplateBinding Padding}"
+                                          Content="{TemplateBinding SelectionBoxItem}"
+                                          ContentTemplate="{TemplateBinding SelectionBoxItemTemplate}"
+                                          ContentStringFormat="{TemplateBinding SelectionBoxItemStringFormat}"
+                                          HorizontalAlignment="Left" VerticalAlignment="Center"
+                                          IsHitTestVisible="False" />
+                        <Popup x:Name="PART_Popup"
+                               Placement="Bottom"
+                               IsOpen="{TemplateBinding IsDropDownOpen}"
+                               AllowsTransparency="True"
+                               Focusable="False"
+                               PopupAnimation="Fade">
+                            <Border Background="{DynamicResource Theme.PopupBackground}"
+                                    BorderBrush="{DynamicResource Theme.ControlBorder}"
+                                    BorderThickness="1"
+                                    CornerRadius="4"
+                                    Margin="0,2,0,0"
+                                    MinWidth="{Binding ActualWidth,
+                                        RelativeSource={RelativeSource TemplatedParent}}"
+                                    MaxHeight="{TemplateBinding MaxDropDownHeight}">
+                                <ScrollViewer>
+                                    <ItemsPresenter KeyboardNavigation.DirectionalNavigation="Contained" />
+                                </ScrollViewer>
+                            </Border>
+                        </Popup>
+                    </Grid>
+                    <ControlTemplate.Triggers>
+                        <Trigger Property="IsEnabled" Value="False">
+                            <Setter Property="Opacity" Value="0.5" />
+                        </Trigger>
+                    </ControlTemplate.Triggers>
+                </ControlTemplate>
+            </Setter.Value>
+        </Setter>
+    </Style>
+
+    <!-- ======================= Slider ======================= -->
+
+    <Style x:Key="SliderThumbStyle" TargetType="Thumb">
+        <Setter Property="OverridesDefaultStyle" Value="True" />
+        <Setter Property="Width" Value="14" />
+        <Setter Property="Height" Value="14" />
+        <Setter Property="Template">
+            <Setter.Value>
+                <ControlTemplate TargetType="Thumb">
+                    <Ellipse x:Name="Circle"
+                             Fill="{DynamicResource Theme.Accent}"
+                             Stroke="{DynamicResource Theme.ControlBackground}"
+                             StrokeThickness="2" />
+                    <ControlTemplate.Triggers>
+                        <Trigger Property="IsMouseOver" Value="True">
+                            <Setter TargetName="Circle" Property="StrokeThickness" Value="1" />
+                        </Trigger>
+                    </ControlTemplate.Triggers>
+                </ControlTemplate>
+            </Setter.Value>
+        </Setter>
+    </Style>
+
+    <!-- Пройденная часть шкалы: закрашивается акцентом -->
+    <Style x:Key="SliderDecreaseStyle" TargetType="RepeatButton">
+        <Setter Property="OverridesDefaultStyle" Value="True" />
+        <Setter Property="Focusable" Value="False" />
+        <Setter Property="IsTabStop" Value="False" />
+        <Setter Property="Template">
+            <Setter.Value>
+                <ControlTemplate TargetType="RepeatButton">
+                    <Border Height="4" CornerRadius="2"
+                            VerticalAlignment="Center"
+                            Background="{DynamicResource Theme.Accent}" />
+                </ControlTemplate>
+            </Setter.Value>
+        </Setter>
+    </Style>
+
+    <Style x:Key="TransparentRepeatStyle" TargetType="RepeatButton">
+        <Setter Property="OverridesDefaultStyle" Value="True" />
+        <Setter Property="Focusable" Value="False" />
+        <Setter Property="IsTabStop" Value="False" />
+        <Setter Property="Template">
+            <Setter.Value>
+                <ControlTemplate TargetType="RepeatButton">
+                    <Border Background="Transparent" />
+                </ControlTemplate>
+            </Setter.Value>
+        </Setter>
+    </Style>
+
+    <Style TargetType="Slider">
+        <Setter Property="VerticalAlignment" Value="Center" />
+        <Setter Property="IsSnapToTickEnabled" Value="True" />
+        <Setter Property="MinHeight" Value="24" />
+        <Setter Property="Template">
+            <Setter.Value>
+                <ControlTemplate TargetType="Slider">
+                    <Grid Background="Transparent">
+                        <Border Height="4" CornerRadius="2"
+                                VerticalAlignment="Center"
+                                Background="{DynamicResource Theme.SliderTrack}" />
+                        <Track x:Name="PART_Track">
+                            <Track.DecreaseRepeatButton>
+                                <RepeatButton Command="Slider.DecreaseLarge"
+                                              Style="{StaticResource SliderDecreaseStyle}" />
+                            </Track.DecreaseRepeatButton>
+                            <Track.Thumb>
+                                <Thumb Style="{StaticResource SliderThumbStyle}" />
+                            </Track.Thumb>
+                            <Track.IncreaseRepeatButton>
+                                <RepeatButton Command="Slider.IncreaseLarge"
+                                              Style="{StaticResource TransparentRepeatStyle}" />
+                            </Track.IncreaseRepeatButton>
+                        </Track>
+                    </Grid>
+                </ControlTemplate>
+            </Setter.Value>
+        </Setter>
+    </Style>
+
+    <!-- ======================= ScrollBar ======================= -->
+
+    <Style x:Key="ScrollBarThumbStyle" TargetType="Thumb">
+        <Setter Property="OverridesDefaultStyle" Value="True" />
+        <Setter Property="Template">
+            <Setter.Value>
+                <ControlTemplate TargetType="Thumb">
+                    <Border Background="{DynamicResource Theme.ScrollBarThumb}"
+                            CornerRadius="3" Margin="3" />
+                </ControlTemplate>
+            </Setter.Value>
+        </Setter>
+    </Style>
+
+    <Style TargetType="ScrollBar">
+        <Setter Property="Background" Value="Transparent" />
+        <Setter Property="Width" Value="12" />
+        <Setter Property="MinWidth" Value="12" />
+        <Setter Property="Template">
+            <Setter.Value>
+                <ControlTemplate TargetType="ScrollBar">
+                    <Grid Background="{TemplateBinding Background}">
+                        <Track x:Name="PART_Track"
+                               Orientation="{TemplateBinding Orientation}"
+                               IsDirectionReversed="True">
+                            <Track.DecreaseRepeatButton>
+                                <RepeatButton Command="ScrollBar.PageUpCommand"
+                                              Style="{StaticResource TransparentRepeatStyle}" />
+                            </Track.DecreaseRepeatButton>
+                            <Track.Thumb>
+                                <Thumb Style="{StaticResource ScrollBarThumbStyle}" />
+                            </Track.Thumb>
+                            <Track.IncreaseRepeatButton>
+                                <RepeatButton Command="ScrollBar.PageDownCommand"
+                                              Style="{StaticResource TransparentRepeatStyle}" />
+                            </Track.IncreaseRepeatButton>
+                        </Track>
+                    </Grid>
+                    <ControlTemplate.Triggers>
+                        <!-- У горизонтальной полосы направление трека обычное -->
+                        <Trigger Property="Orientation" Value="Horizontal">
+                            <Setter TargetName="PART_Track" Property="IsDirectionReversed" Value="False" />
+                        </Trigger>
+                    </ControlTemplate.Triggers>
+                </ControlTemplate>
+            </Setter.Value>
+        </Setter>
+        <Style.Triggers>
+            <Trigger Property="Orientation" Value="Horizontal">
+                <Setter Property="Width" Value="Auto" />
+                <Setter Property="MinWidth" Value="0" />
+                <Setter Property="Height" Value="12" />
+                <Setter Property="MinHeight" Value="12" />
+            </Trigger>
+        </Style.Triggers>
+    </Style>
+
+</ResourceDictionary>

CursorLang/Themes/Dark.xaml

@@ -0,0 +1,21 @@
+<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
+
+    <SolidColorBrush x:Key="Theme.WindowBackground" Color="#1E1E21" />
+    <SolidColorBrush x:Key="Theme.Foreground" Color="#E8E8EA" />
+    <SolidColorBrush x:Key="Theme.SecondaryForeground" Color="#9A9AA2" />
+
+    <SolidColorBrush x:Key="Theme.Surface" Color="#26262A" />
+    <SolidColorBrush x:Key="Theme.SurfaceStrong" Color="#303036" />
+
+    <SolidColorBrush x:Key="Theme.ControlBackground" Color="#2C2C31" />
+    <SolidColorBrush x:Key="Theme.ControlHoverBackground" Color="#38383E" />
+    <SolidColorBrush x:Key="Theme.ControlBorder" Color="#46464C" />
+    <SolidColorBrush x:Key="Theme.PopupBackground" Color="#2A2A2F" />
+    <SolidColorBrush x:Key="Theme.SelectionBackground" Color="#3A4665" />
+
+    <SolidColorBrush x:Key="Theme.Accent" Color="#5B8CF7" />
+    <SolidColorBrush x:Key="Theme.SliderTrack" Color="#46464C" />
+    <SolidColorBrush x:Key="Theme.ScrollBarThumb" Color="#55555C" />
+
+</ResourceDictionary>

CursorLang/Themes/Light.xaml

@@ -0,0 +1,21 @@
+<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
+
+    <SolidColorBrush x:Key="Theme.WindowBackground" Color="#FFFFFF" />
+    <SolidColorBrush x:Key="Theme.Foreground" Color="#1B1B1F" />
+    <SolidColorBrush x:Key="Theme.SecondaryForeground" Color="#6B6B70" />
+
+    <SolidColorBrush x:Key="Theme.Surface" Color="#FAFAFB" />
+    <SolidColorBrush x:Key="Theme.SurfaceStrong" Color="#EFEFF1" />
+
+    <SolidColorBrush x:Key="Theme.ControlBackground" Color="#FFFFFF" />
+    <SolidColorBrush x:Key="Theme.ControlHoverBackground" Color="#F2F2F4" />
+    <SolidColorBrush x:Key="Theme.ControlBorder" Color="#D0D0D4" />
+    <SolidColorBrush x:Key="Theme.PopupBackground" Color="#FFFFFF" />
+    <SolidColorBrush x:Key="Theme.SelectionBackground" Color="#E4EBFB" />
+
+    <SolidColorBrush x:Key="Theme.Accent" Color="#2563EB" />
+    <SolidColorBrush x:Key="Theme.SliderTrack" Color="#DCDCE0" />
+    <SolidColorBrush x:Key="Theme.ScrollBarThumb" Color="#C2C2C7" />
+
+</ResourceDictionary>

CursorLang/ViewModels/SettingsViewModel.cs

@@ -62,6 +62,7 @@ public sealed partial class SettingsViewModel : ObservableObject, IDisposable
         Settings.PropertyChanged += OnSettingsChanged;
         Localization.PropertyChanged += OnLocalizationChanged;
 
+        Themes = CreateOptions<AppTheme>();
         PlacementModes = CreateOptions<PopupPlacementMode>();
         AnchorSides = CreateOptions<AnchorSide>();
         ScreenPositions = CreateOptions<ScreenPosition>();
@@ -73,6 +74,8 @@ public sealed partial class SettingsViewModel : ObservableObject, IDisposable
 
     public IReadOnlyList<Color> BackgroundPalette { get; } = Palette;
 
+    public IReadOnlyList<EnumOption<AppTheme>> Themes { get; }
+
     public IReadOnlyList<EnumOption<PopupPlacementMode>> PlacementModes { get; }
 
     public IReadOnlyList<EnumOption<AnchorSide>> AnchorSides { get; }
@@ -102,6 +105,7 @@ public sealed partial class SettingsViewModel : ObservableObject, IDisposable
             return;
         }
 
+        Translate(Themes);
         Translate(PlacementModes);
         Translate(AnchorSides);
         Translate(ScreenPositions);

CursorLang/Views/MainWindow.xaml

@@ -9,7 +9,9 @@
         d:DataContext="{d:DesignInstance Type=vm:SettingsViewModel}"
         Title="{Binding Localization[SettingsTitle]}"
         Width="560" SizeToContent="Height" MaxHeight="900"
-        ResizeMode="CanMinimize">
+        ResizeMode="CanMinimize"
+        Background="{DynamicResource Theme.WindowBackground}"
+        Foreground="{DynamicResource Theme.Foreground}">
     <Window.Resources>
         <local:EnumToVisibilityConverter x:Key="EnumToVisibility" />
         <local:ColorToBrushConverter x:Key="ColorToBrush" />
@@ -24,18 +26,7 @@
             <Setter Property="Margin" Value="12,0,0,0" />
             <Setter Property="MinWidth" Value="48" />
             <Setter Property="TextAlignment" Value="Right" />
-            <Setter Property="Foreground" Value="#666" />
+            <Setter Property="Foreground" Value="{DynamicResource Theme.SecondaryForeground}" />
-        </Style>
-        <Style TargetType="GroupBox">
-            <Setter Property="Padding" Value="12" />
-            <Setter Property="Margin" Value="0,0,0,12" />
-        </Style>
-        <Style TargetType="ComboBox">
-            <Setter Property="VerticalAlignment" Value="Center" />
-        </Style>
-        <Style TargetType="Slider">
-            <Setter Property="VerticalAlignment" Value="Center" />
-            <Setter Property="IsSnapToTickEnabled" Value="True" />
         </Style>
     </Window.Resources>
 
@@ -48,6 +39,11 @@
                         <ColumnDefinition Width="180" />
                         <ColumnDefinition Width="*" />
                     </Grid.ColumnDefinitions>
+                    <Grid.RowDefinitions>
+                        <RowDefinition Height="Auto" />
+                        <RowDefinition Height="Auto" />
+                    </Grid.RowDefinitions>
+
                     <TextBlock Style="{StaticResource FieldLabel}"
                                Text="{Binding Localization[LanguageLabel]}" />
                     <ComboBox Grid.Column="1"
@@ -55,6 +51,15 @@
                               DisplayMemberPath="DisplayName"
                               SelectedValuePath="Code"
                               SelectedValue="{Binding Settings.Language}" />
+
+                    <TextBlock Grid.Row="1" Margin="0,12,12,0"
+                               Style="{StaticResource FieldLabel}"
+                               Text="{Binding Localization[ThemeLabel]}" />
+                    <ComboBox Grid.Row="1" Grid.Column="1" Margin="0,12,0,0"
+                              ItemsSource="{Binding Themes}"
+                              DisplayMemberPath="Display"
+                              SelectedValuePath="Value"
+                              SelectedValue="{Binding Settings.Theme}" />
                 </Grid>
             </GroupBox>
 
@@ -245,7 +250,7 @@
                                Text="{Binding Localization[PreviewLabel]}" />
                     <Border Grid.Row="3" Grid.Column="1" Grid.ColumnSpan="2"
                             Margin="0,12,0,0" Padding="16"
-                            Background="#F0F0F0" CornerRadius="4"
+                            Background="{DynamicResource Theme.SurfaceStrong}" CornerRadius="4"
                             HorizontalAlignment="Stretch">
                         <Border CornerRadius="4" Padding="10,4"
                                 HorizontalAlignment="Center"
@@ -273,7 +278,8 @@
                     <StackPanel Grid.Column="2" Orientation="Horizontal" VerticalAlignment="Center">
                         <TextBlock Style="{StaticResource FieldValue}"
                                    Text="{Binding Settings.DurationMilliseconds, StringFormat={}{0:F0}}" />
-                        <TextBlock Margin="4,0,0,0" Foreground="#666"
+                        <TextBlock Margin="4,0,0,0"
+                                   Foreground="{DynamicResource Theme.SecondaryForeground}"
                                    Text="{Binding Localization[MillisecondsSuffix]}" />
                     </StackPanel>
                 </Grid>

CursorLang/Views/MainWindow.xaml.cs

@@ -1,4 +1,5 @@
 using System.Windows;
+using CursorLang.Services;
 using CursorLang.ViewModels;
 
 namespace CursorLang.Views;
@@ -8,9 +9,10 @@ namespace CursorLang.Views;
 /// </summary>
 public partial class MainWindow : Window
 {
-    public MainWindow(SettingsViewModel viewModel)
+    public MainWindow(SettingsViewModel viewModel, IThemeService theme)
     {
         InitializeComponent();
         DataContext = viewModel;
+        theme.Register(this);
     }
 }