feat.圆角体系加入Fluent，设置页面全面使用Fluent Design System

LanMountainDesktop.Appearance/AppearanceCornerRadiusTokenFactory.cs

@@ -38,6 +38,15 @@ public static class AppearanceCornerRadiusTokenFactory
                 Xl: new CornerRadius(40),
                 Island: new CornerRadius(44),
                 Component: new CornerRadius(32)),
+            GlobalAppearanceSettings.CornerRadiusStyleFluent => new AppearanceCornerRadiusTokens(
+                Micro: new CornerRadius(2),
+                Xs: new CornerRadius(4),
+                Sm: new CornerRadius(4),
+                Md: new CornerRadius(8),
+                Lg: new CornerRadius(8),
+                Xl: new CornerRadius(12),
+                Island: new CornerRadius(16),
+                Component: new CornerRadius(8)),
             // Balanced (default)
             _ => new AppearanceCornerRadiusTokens(
                 Micro: new CornerRadius(6),

LanMountainDesktop.Settings.Core/GlobalAppearanceSettings.cs

@@ -6,6 +6,7 @@ public static class GlobalAppearanceSettings
     public const string CornerRadiusStyleBalanced = "Balanced";
     public const string CornerRadiusStyleRounded = "Rounded";
     public const string CornerRadiusStyleOpen = "Open";
+    public const string CornerRadiusStyleFluent = "Fluent";
     public const string DefaultCornerRadiusStyle = CornerRadiusStyleBalanced;
 
     /// <summary>
@@ -43,6 +44,11 @@ public static class GlobalAppearanceSettings
             return CornerRadiusStyleOpen;
         }
 
+        if (string.Equals(trimmed, CornerRadiusStyleFluent, StringComparison.OrdinalIgnoreCase))
+        {
+            return CornerRadiusStyleFluent;
+        }
+
         return DefaultCornerRadiusStyle;
     }
 
@@ -51,7 +57,8 @@ public static class GlobalAppearanceSettings
         CornerRadiusStyleSharp,
         CornerRadiusStyleBalanced,
         CornerRadiusStyleRounded,
-        CornerRadiusStyleOpen
+        CornerRadiusStyleOpen,
+        CornerRadiusStyleFluent
     ];
 
     /// <summary>

LanMountainDesktop.Tests/CornerRadiusStyleTests.cs

@@ -13,6 +13,7 @@ public sealed class CornerRadiusStyleTests
     [InlineData("Balanced", "Balanced")]
     [InlineData("Rounded", "Rounded")]
     [InlineData("Open", "Open")]
+    [InlineData("Fluent", "Fluent")]
     [InlineData("Unknown", "Balanced")]
     [InlineData(null, "Balanced")]
     public void NormalizeCornerRadiusStyle_ReturnsValidStyleOrDefault(string? input, string expected)
@@ -20,6 +21,23 @@ public sealed class CornerRadiusStyleTests
         Assert.Equal(expected, GlobalAppearanceSettings.NormalizeCornerRadiusStyle(input));
     }
 
+    [Fact]
+    public void FluentStyle_ReturnsFluentDesignSystemValues()
+    {
+        var tokens = LanMountainDesktop.Appearance.AppearanceCornerRadiusTokenFactory.Create(
+            GlobalAppearanceSettings.CornerRadiusStyleFluent);
+
+        // Microsoft Fluent Design System: ControlCornerRadius = 4px, OverlayCornerRadius = 8px
+        Assert.Equal(new CornerRadius(2), tokens.Micro);
+        Assert.Equal(new CornerRadius(4), tokens.Xs);
+        Assert.Equal(new CornerRadius(4), tokens.Sm);
+        Assert.Equal(new CornerRadius(8), tokens.Md);
+        Assert.Equal(new CornerRadius(8), tokens.Lg);
+        Assert.Equal(new CornerRadius(12), tokens.Xl);
+        Assert.Equal(new CornerRadius(16), tokens.Island);
+        Assert.Equal(new CornerRadius(8), tokens.Component);
+    }
+
     [Fact]
     public void PluginAppearanceContext_ResolveCornerRadius_ReturnsFixedTokenValues()
     {

LanMountainDesktop/Views/SettingsWindow.axaml.cs

@@ -10,9 +10,11 @@ using Avalonia.Threading;
 using Avalonia.VisualTree;
 using FluentAvalonia.UI.Controls;
 using FluentAvalonia.UI.Windowing;
+using LanMountainDesktop.Appearance;
 using LanMountainDesktop.PluginSdk;
 using LanMountainDesktop.Services;
 using LanMountainDesktop.Services.Settings;
+using LanMountainDesktop.Settings.Core;
 using LanMountainDesktop.ViewModels;
 using Symbol = FluentIcons.Common.Symbol;
 
@@ -69,6 +71,7 @@ public partial class SettingsWindow : FAAppWindow, ISettingsPageHostContext
         InitializeComponent();
         SetValue(Window.IconProperty, _appLogoService.CreateWindowIcon());
         ApplyChromeMode(useSystemChrome);
+        ApplyFluentCornerRadius();
 
         if (RootNavigationView is not null)
         {
@@ -798,6 +801,30 @@ public partial class SettingsWindow : FAAppWindow, ISettingsPageHostContext
         TelemetryServices.Usage?.TrackSettingsWindowClosed("SettingsWindow.OnClosed", ViewModel.CurrentPageId);
     }
 
+    /// <summary>
+    /// Override global corner radius tokens on the settings window root grid
+    /// so all child controls use Microsoft Fluent Design System values,
+    /// independent of the user's global corner radius preference.
+    /// </summary>
+    private void ApplyFluentCornerRadius()
+    {
+        if (RootGrid is null)
+        {
+            return;
+        }
+
+        var tokens = AppearanceCornerRadiusTokenFactory.Create(
+            GlobalAppearanceSettings.CornerRadiusStyleFluent);
+        RootGrid.Resources["DesignCornerRadiusMicro"] = tokens.Micro;
+        RootGrid.Resources["DesignCornerRadiusXs"] = tokens.Xs;
+        RootGrid.Resources["DesignCornerRadiusSm"] = tokens.Sm;
+        RootGrid.Resources["DesignCornerRadiusMd"] = tokens.Md;
+        RootGrid.Resources["DesignCornerRadiusLg"] = tokens.Lg;
+        RootGrid.Resources["DesignCornerRadiusXl"] = tokens.Xl;
+        RootGrid.Resources["DesignCornerRadiusIsland"] = tokens.Island;
+        RootGrid.Resources["DesignCornerRadiusComponent"] = tokens.Component;
+    }
+
     private void OnTitleBarDragZonePointerPressed(object? sender, PointerPressedEventArgs e)
     {
         _ = sender;

docs/CORNER_RADIUS_SPEC.md

@@ -4,11 +4,13 @@
 
 为了确保桌面组件在不同尺寸、缩放比例下都能保持视觉一致性和美感，阑山桌面采用了 **固定圆角风格预设 (Fixed Corner Radius Styles)**，全面参考小米澎湃OS (Xiaomi HyperOS) 的设计语言。
 
+此外，阑山桌面引入了 **Fluent** 预设，遵循 Microsoft Fluent Design System 规范。设置窗口始终使用 Fluent 圆角，独立于用户选择的全局圆角风格。
+
 所有的组件和容器必须使用统一的资源键，禁止在 XAML 或代码中使用硬编码的像素值。
 
 ## 预设风格 (Preset Styles)
 
-用户可以在设置中选择以下四种风格之一。系统会自动根据选中的风格动态映射全局圆角 Token。
+用户可以在设置中选择以下五种风格之一。系统会自动根据选中的风格动态映射全局圆角 Token。
 
 | 风格 (ID) | 名称 (Local) | 组件圆角 (Component) | 设计语义 |
 | :--- | :--- | :--- | :--- |
@@ -16,21 +18,33 @@
 | **Balanced** | 平衡 | 24px | **默认值**。和谐、自然、普适 |
 | **Rounded** | 圆润 | 28px | 保守、柔和、亲切 |
 | **Open** | 开放 | 32px | 现代、沉浸、夸张 |
+| **Fluent** | Fluent | 8px | Microsoft Fluent Design System。标准、规范、一致 |
 
 ## Token 阶梯映射 (Token Step Mapping)
 
 每个风格都定义了一套完整的圆角阶梯，以确保在大容器包裹小元素时满足 **圆角嵌套一致性 (Nesting Consistency)**。
 
-| Token | Sharp | Balanced | Rounded | Open | 典型场景 |
-| :--- | :--- | :--- | :--- | :--- | :--- |
-| **Micro** | 4px | 6px | 8px | 10px | 小图标容器、角标 (Badge) |
-| **Xs** | 8px | 12px | 14px | 16px | 小标签 (Tag)、输入框 |
-| **Sm** | 10px | 14px | 16px | 20px | 普通按钮、搜索栏、复选框 |
-| **Md** | 14px | 20px | 24px | 28px | 悬浮菜单、小提示框、子卡片 |
-| **Lg** | 20px | 28px | 32px | 36px | 普通面板、对话框内容区 |
-| **Xl** | 24px | 32px | 36px | 40px | 大尺寸容器、设置中心页面 |
-| **Island** | 28px | 36px | 40px | 44px | 任务栏、全局大悬浮容器 |
-| **Component** | **20px** | **24px** | **28px** | **32px** | **所有桌面组件 (Widget) 的主边框** |
+| Token | Sharp | Balanced | Rounded | Open | Fluent | 典型场景 |
+| :--- | :--- | :--- | :--- | :--- | :--- | :--- |
+| **Micro** | 4px | 6px | 8px | 10px | 2px | 小图标容器、角标 (Badge) |
+| **Xs** | 8px | 12px | 14px | 16px | 4px | 小标签 (Tag)、输入框 |
+| **Sm** | 10px | 14px | 16px | 20px | 4px | 普通按钮、搜索栏、复选框 |
+| **Md** | 14px | 20px | 24px | 28px | 8px | 悬浮菜单、小提示框、子卡片 |
+| **Lg** | 20px | 28px | 32px | 36px | 8px | 普通面板、对话框内容区 |
+| **Xl** | 24px | 32px | 36px | 40px | 12px | 大尺寸容器、设置中心页面 |
+| **Island** | 28px | 36px | 40px | 44px | 16px | 任务栏、全局大悬浮容器 |
+| **Component** | **20px** | **24px** | **28px** | **32px** | **8px** | **所有桌面组件 (Widget) 的主边框** |
+
+## Fluent Design System 参考 (Fluent Reference)
+
+Fluent 预设的核心值来源于 Microsoft 官方规范：
+
+- **ControlCornerRadius = 4px**：用于标准持久 UI 元素（按钮、复选框、输入框等）
+- **OverlayCornerRadius = 8px**：用于临时覆盖 UI 元素（对话框、浮出菜单等）
+
+> [!IMPORTANT]
+> **设置窗口强制约束**：
+> 设置窗口 (`SettingsWindow`) 始终使用 Fluent 圆角 Token，不受用户全局圆角设置影响。这确保设置 UI 作为标准 Windows 应用窗口与 Fluent Design 一致。
 
 ## 开发准则 (Implementation Rules)