diff --git a/TeamsISO.Windows.slnf b/TeamsISO.Windows.slnf
index 63a318d..dd110d4 100644
--- a/TeamsISO.Windows.slnf
+++ b/TeamsISO.Windows.slnf
@@ -2,13 +2,14 @@
   "solution": {
     "path": "TeamsISO.sln",
     "projects": [
-      "src/TeamsISO.Engine/TeamsISO.Engine.csproj",
-      "src/TeamsISO.Engine.NdiInterop/TeamsISO.Engine.NdiInterop.csproj",
-      "src/TeamsISO.Console/TeamsISO.Console.csproj",
-      "src/TeamsISO.App/TeamsISO.App.csproj",
-      "src/tests/TeamsISO.Engine.Tests/TeamsISO.Engine.Tests.csproj",
-      "src/tests/TeamsISO.Engine.IntegrationTests/TeamsISO.Engine.IntegrationTests.csproj",
-      "src/tests/TeamsISO.App.Tests/TeamsISO.App.Tests.csproj"
+      "src\\TeamsISO.Engine\\TeamsISO.Engine.csproj",
+      "src\\TeamsISO.Engine.NdiInterop\\TeamsISO.Engine.NdiInterop.csproj",
+      "src\\TeamsISO.Console\\TeamsISO.Console.csproj",
+      "src\\TeamsISO.App\\TeamsISO.App.csproj",
+      "src\\TeamsISO.App.WinUI\\TeamsISO.App.WinUI.csproj",
+      "src\\tests\\TeamsISO.Engine.Tests\\TeamsISO.Engine.Tests.csproj",
+      "src\\tests\\TeamsISO.Engine.IntegrationTests\\TeamsISO.Engine.IntegrationTests.csproj",
+      "src\\tests\\TeamsISO.App.Tests\\TeamsISO.App.Tests.csproj"
     ]
   }
 }
diff --git a/TeamsISO.sln b/TeamsISO.sln
index 2cfa517..32c24bc 100644
--- a/TeamsISO.sln
+++ b/TeamsISO.sln
@@ -5,21 +5,23 @@ VisualStudioVersion = 17.0.31903.59
 MinimumVisualStudioVersion = 10.0.40219.1
 Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "src", "src", "{46E05E34-8A87-4986-87D3-FE0DE4E05F44}"
 EndProject
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "TeamsISO.Engine", "src/TeamsISO.Engine/TeamsISO.Engine.csproj", "{F0D24EAE-9225-4DC4-B3D2-6966077287A0}"
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "TeamsISO.Engine", "src\TeamsISO.Engine\TeamsISO.Engine.csproj", "{F0D24EAE-9225-4DC4-B3D2-6966077287A0}"
 EndProject
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "TeamsISO.Engine.NdiInterop", "src/TeamsISO.Engine.NdiInterop/TeamsISO.Engine.NdiInterop.csproj", "{E737E54B-73DE-4F74-909C-1F0F5CF82AC6}"
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "TeamsISO.Engine.NdiInterop", "src\TeamsISO.Engine.NdiInterop\TeamsISO.Engine.NdiInterop.csproj", "{E737E54B-73DE-4F74-909C-1F0F5CF82AC6}"
 EndProject
 Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "tests", "tests", "{DBDF4A1D-4215-42D5-B456-2CE7159DF848}"
 EndProject
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "TeamsISO.Engine.Tests", "src/tests/TeamsISO.Engine.Tests/TeamsISO.Engine.Tests.csproj", "{F8DBD7AB-E160-4B75-88FC-BAECDD4D44E8}"
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "TeamsISO.Engine.Tests", "src\tests\TeamsISO.Engine.Tests\TeamsISO.Engine.Tests.csproj", "{F8DBD7AB-E160-4B75-88FC-BAECDD4D44E8}"
 EndProject
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "TeamsISO.App", "src/TeamsISO.App/TeamsISO.App.csproj", "{80DCE039-3BBC-4D3F-B44B-51F324591C29}"
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "TeamsISO.App", "src\TeamsISO.App\TeamsISO.App.csproj", "{80DCE039-3BBC-4D3F-B44B-51F324591C29}"
 EndProject
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "TeamsISO.Engine.IntegrationTests", "src/tests/TeamsISO.Engine.IntegrationTests/TeamsISO.Engine.IntegrationTests.csproj", "{A85E331D-026E-4BDE-B89C-0CC4C95001CE}"
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "TeamsISO.Engine.IntegrationTests", "src\tests\TeamsISO.Engine.IntegrationTests\TeamsISO.Engine.IntegrationTests.csproj", "{A85E331D-026E-4BDE-B89C-0CC4C95001CE}"
 EndProject
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "TeamsISO.Console", "src/TeamsISO.Console/TeamsISO.Console.csproj", "{C3254998-9428-4264-A8FB-EAC9E1F9F432}"
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "TeamsISO.Console", "src\TeamsISO.Console\TeamsISO.Console.csproj", "{C3254998-9428-4264-A8FB-EAC9E1F9F432}"
 EndProject
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "TeamsISO.App.Tests", "src/tests/TeamsISO.App.Tests/TeamsISO.App.Tests.csproj", "{B5A6F1E7-3D2C-4F89-9A55-7E1B2A4C8D6F}"
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "TeamsISO.App.Tests", "src\tests\TeamsISO.App.Tests\TeamsISO.App.Tests.csproj", "{B5A6F1E7-3D2C-4F89-9A55-7E1B2A4C8D6F}"
+EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "TeamsISO.App.WinUI", "src\TeamsISO.App.WinUI\TeamsISO.App.WinUI.csproj", "{14928B5A-E45C-4265-A5D7-D13B5ED18F84}"
 EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
@@ -58,6 +60,10 @@ Global
 		{B5A6F1E7-3D2C-4F89-9A55-7E1B2A4C8D6F}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{B5A6F1E7-3D2C-4F89-9A55-7E1B2A4C8D6F}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{B5A6F1E7-3D2C-4F89-9A55-7E1B2A4C8D6F}.Release|Any CPU.Build.0 = Release|Any CPU
+		{14928B5A-E45C-4265-A5D7-D13B5ED18F84}.Debug|Any CPU.ActiveCfg = Debug|x64
+		{14928B5A-E45C-4265-A5D7-D13B5ED18F84}.Debug|Any CPU.Build.0 = Debug|x64
+		{14928B5A-E45C-4265-A5D7-D13B5ED18F84}.Release|Any CPU.ActiveCfg = Release|x64
+		{14928B5A-E45C-4265-A5D7-D13B5ED18F84}.Release|Any CPU.Build.0 = Release|x64
 	EndGlobalSection
 	GlobalSection(NestedProjects) = preSolution
 		{F0D24EAE-9225-4DC4-B3D2-6966077287A0} = {46E05E34-8A87-4986-87D3-FE0DE4E05F44}
@@ -68,5 +74,6 @@ Global
 		{A85E331D-026E-4BDE-B89C-0CC4C95001CE} = {DBDF4A1D-4215-42D5-B456-2CE7159DF848}
 		{C3254998-9428-4264-A8FB-EAC9E1F9F432} = {46E05E34-8A87-4986-87D3-FE0DE4E05F44}
 		{B5A6F1E7-3D2C-4F89-9A55-7E1B2A4C8D6F} = {DBDF4A1D-4215-42D5-B456-2CE7159DF848}
+		{14928B5A-E45C-4265-A5D7-D13B5ED18F84} = {46E05E34-8A87-4986-87D3-FE0DE4E05F44}
 	EndGlobalSection
 EndGlobal
diff --git a/src/TeamsISO.App.WinUI/App.xaml b/src/TeamsISO.App.WinUI/App.xaml
new file mode 100644
index 0000000..09782b0
--- /dev/null
+++ b/src/TeamsISO.App.WinUI/App.xaml
@@ -0,0 +1,21 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Application
+    x:Class="TeamsISO.App.WinUI.App"
+    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
+    <Application.Resources>
+        <ResourceDictionary>
+            <ResourceDictionary.MergedDictionaries>
+                <!--
+                    Tokens.xaml owns the color/typography/spacing primitives in
+                    a ThemeDictionary so {ThemeResource} on the consumer side
+                    auto-swaps when RequestedTheme flips. Controls.xaml owns
+                    the actual Style targets (Button, TextBlock, etc.) and
+                    references the tokens via {ThemeResource}.
+                -->
+                <ResourceDictionary Source="ms-appx:///Themes/Tokens.xaml"/>
+                <ResourceDictionary Source="ms-appx:///Themes/Controls.xaml"/>
+            </ResourceDictionary.MergedDictionaries>
+        </ResourceDictionary>
+    </Application.Resources>
+</Application>
diff --git a/src/TeamsISO.App.WinUI/App.xaml.cs b/src/TeamsISO.App.WinUI/App.xaml.cs
new file mode 100644
index 0000000..01eb562
--- /dev/null
+++ b/src/TeamsISO.App.WinUI/App.xaml.cs
@@ -0,0 +1,38 @@
+using Microsoft.UI.Xaml;
+using TeamsISO.App.WinUI.Views;
+
+namespace TeamsISO.App.WinUI;
+
+/// <summary>
+/// WinUI 3 application entry. The full startup pipeline from the WPF host
+/// (NDI runtime preflight, IsoController wiring, single-instance mutex, REST
+/// + OSC bridge, tray icon, crash diagnostics, auto-update banner, onboarding)
+/// will migrate over in subsequent commits — this initial scaffold just brings
+/// up MainWindow so the redesigned shell can be developed and previewed.
+///
+/// The engine layer (TeamsISO.Engine) is unchanged; the WinUI 3 host's
+/// responsibility is binding its view-models to the same controller surface
+/// the WPF host already uses.
+/// </summary>
+public partial class App : Application
+{
+    private Window? _mainWindow;
+
+    public App()
+    {
+        InitializeComponent();
+    }
+
+    protected override void OnLaunched(LaunchActivatedEventArgs args)
+    {
+        _mainWindow = new MainWindow();
+        _mainWindow.Activate();
+    }
+
+    /// <summary>
+    /// Exposes the active main window so settings can swap RequestedTheme on
+    /// the root element without having to thread the Window reference through
+    /// every consumer.
+    /// </summary>
+    internal Window? MainWindow => _mainWindow;
+}
diff --git a/src/TeamsISO.App.WinUI/Assets/Fonts/Inter.ttf b/src/TeamsISO.App.WinUI/Assets/Fonts/Inter.ttf
new file mode 100644
index 0000000..1cb674b
Binary files /dev/null and b/src/TeamsISO.App.WinUI/Assets/Fonts/Inter.ttf differ
diff --git a/src/TeamsISO.App.WinUI/Assets/Fonts/JetBrainsMono.ttf b/src/TeamsISO.App.WinUI/Assets/Fonts/JetBrainsMono.ttf
new file mode 100644
index 0000000..b60e77f
Binary files /dev/null and b/src/TeamsISO.App.WinUI/Assets/Fonts/JetBrainsMono.ttf differ
diff --git a/src/TeamsISO.App.WinUI/Assets/dragon-mark.png b/src/TeamsISO.App.WinUI/Assets/dragon-mark.png
new file mode 100644
index 0000000..d78b7cf
Binary files /dev/null and b/src/TeamsISO.App.WinUI/Assets/dragon-mark.png differ
diff --git a/src/TeamsISO.App.WinUI/Assets/teamsiso.ico b/src/TeamsISO.App.WinUI/Assets/teamsiso.ico
new file mode 100644
index 0000000..b7be1cf
Binary files /dev/null and b/src/TeamsISO.App.WinUI/Assets/teamsiso.ico differ
diff --git a/src/TeamsISO.App.WinUI/Assets/wild-dragon-wordmark.png b/src/TeamsISO.App.WinUI/Assets/wild-dragon-wordmark.png
new file mode 100644
index 0000000..ed0804c
Binary files /dev/null and b/src/TeamsISO.App.WinUI/Assets/wild-dragon-wordmark.png differ
diff --git a/src/TeamsISO.App.WinUI/TeamsISO.App.WinUI.csproj b/src/TeamsISO.App.WinUI/TeamsISO.App.WinUI.csproj
new file mode 100644
index 0000000..03de33e
--- /dev/null
+++ b/src/TeamsISO.App.WinUI/TeamsISO.App.WinUI.csproj
@@ -0,0 +1,72 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <!--
+    TeamsISO WinUI 3 host. Coexists with the WPF project (src/TeamsISO.App)
+    during the redesign migration. Shares the engine (TeamsISO.Engine) and
+    the NDI interop assembly via ProjectReference. Once the WinUI 3 build is
+    feature-complete and tested against a real Teams meeting, the WPF
+    project is retired and this becomes the only shipping host.
+
+    Target framework choice: net8.0-windows10.0.19041.0 is the minimum the
+    Windows App SDK supports cleanly. Going higher (e.g. 22621) would lock
+    out Win10 1809+ operators, which is undesirable for a broadcast tool
+    that still has to run on hardware in working broadcast suites.
+
+    Packaging mode: WindowsPackageType=None for "unpackaged" — the .exe
+    drops directly into Program Files via the existing MSI rather than
+    going through MSIX. The Windows App Runtime install becomes a prereq
+    of the MSI (or bootstrapped at startup), which matches how operators
+    install NDI Runtime today.
+  -->
+  <PropertyGroup>
+    <OutputType>WinExe</OutputType>
+    <TargetFramework>net8.0-windows10.0.19041.0</TargetFramework>
+    <TargetPlatformMinVersion>10.0.17763.0</TargetPlatformMinVersion>
+    <SupportedOSPlatformVersion>10.0.17763.0</SupportedOSPlatformVersion>
+    <RootNamespace>TeamsISO.App.WinUI</RootNamespace>
+    <AssemblyName>TeamsISO</AssemblyName>
+    <ApplicationManifest>app.manifest</ApplicationManifest>
+    <Platforms>x64;ARM64</Platforms>
+    <RuntimeIdentifiers>win-x64;win-arm64</RuntimeIdentifiers>
+    <UseWinUI>true</UseWinUI>
+    <WindowsPackageType>None</WindowsPackageType>
+    <EnableMsixTooling>true</EnableMsixTooling>
+    <!--
+      Pinning the Windows SDK projection package: WindowsAppSDK 1.6 requires
+      Microsoft.Windows.SDK.NET.Ref >= 10.0.19041.38, but the .NET 8.0.301
+      SDK installed here ships an older Ref. Setting this explicitly avoids
+      having to upgrade the .NET SDK on the build host.
+    -->
+    <WindowsSdkPackageVersion>10.0.19041.38</WindowsSdkPackageVersion>
+    <Nullable>enable</Nullable>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <ApplicationIcon>Assets\teamsiso.ico</ApplicationIcon>
+    <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
+  </PropertyGroup>
+
+  <!--
+    WindowsAppSDK 1.6 is the current LTS branch (Win10 1809-compatible at
+    a 10.0.17763 floor, which matches our SupportedOSPlatformVersion).
+    DataGrid lives in the older 7.x Community Toolkit because the 8.x line
+    dropped it; 7.1.2 still works on WinUI 3 / WindowsAppSDK 1.6 and is the
+    only currently-maintained free DataGrid for this stack.
+  -->
+  <ItemGroup>
+    <PackageReference Include="Microsoft.WindowsAppSDK" Version="1.6.250602001" />
+    <PackageReference Include="CommunityToolkit.WinUI.UI.Controls.DataGrid" Version="7.1.2" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\TeamsISO.Engine\TeamsISO.Engine.csproj" />
+    <ProjectReference Include="..\TeamsISO.Engine.NdiInterop\TeamsISO.Engine.NdiInterop.csproj" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <Content Include="Assets\teamsiso.ico" />
+    <Content Include="Assets\dragon-mark.png" />
+    <Content Include="Assets\wild-dragon-wordmark.png" />
+    <Content Include="Assets\Fonts\Inter.ttf" />
+    <Content Include="Assets\Fonts\JetBrainsMono.ttf" />
+  </ItemGroup>
+
+</Project>
diff --git a/src/TeamsISO.App.WinUI/Themes/Controls.xaml b/src/TeamsISO.App.WinUI/Themes/Controls.xaml
new file mode 100644
index 0000000..3c3bb59
--- /dev/null
+++ b/src/TeamsISO.App.WinUI/Themes/Controls.xaml
@@ -0,0 +1,170 @@
+<?xml version="1.0" encoding="utf-8"?>
+<ResourceDictionary
+    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
+
+    <!--
+        Control styles. Where WPF needed full ControlTemplate overrides to
+        achieve the Wild Dragon look, WinUI 3's built-in VisualStateManager
+        handles hover / pressed / focus states cleanly, so most styles here
+        just set surface properties (background, foreground, padding, corner
+        radius) and the framework handles state.
+
+        The few exceptions — rail icon button, ISO toggle pill — re-template
+        because their interaction model (Teams-style hover wash; status-coded
+        pill that preserves background on hover) doesn't fit the default
+        Button template.
+    -->
+
+    <!-- ════════════ TextBlock (typographic ramp) ════════════ -->
+
+    <Style x:Key="TextDisplay" TargetType="TextBlock">
+        <Setter Property="FontFamily" Value="{ThemeResource FontSans}"/>
+        <Setter Property="FontSize" Value="{ThemeResource TextDisplaySize}"/>
+        <Setter Property="FontWeight" Value="SemiBold"/>
+        <Setter Property="Foreground" Value="{ThemeResource FgPrimary}"/>
+        <Setter Property="LineHeight" Value="26"/>
+    </Style>
+
+    <Style x:Key="TextTitle" TargetType="TextBlock">
+        <Setter Property="FontFamily" Value="{ThemeResource FontSans}"/>
+        <Setter Property="FontSize" Value="{ThemeResource TextTitleSize}"/>
+        <Setter Property="FontWeight" Value="SemiBold"/>
+        <Setter Property="Foreground" Value="{ThemeResource FgPrimary}"/>
+    </Style>
+
+    <Style x:Key="TextHeading" TargetType="TextBlock">
+        <Setter Property="FontFamily" Value="{ThemeResource FontSans}"/>
+        <Setter Property="FontSize" Value="{ThemeResource TextHeadingSize}"/>
+        <Setter Property="FontWeight" Value="SemiBold"/>
+        <Setter Property="Foreground" Value="{ThemeResource FgPrimary}"/>
+    </Style>
+
+    <Style x:Key="TextBody" TargetType="TextBlock">
+        <Setter Property="FontFamily" Value="{ThemeResource FontSans}"/>
+        <Setter Property="FontSize" Value="{ThemeResource TextBodySize}"/>
+        <Setter Property="Foreground" Value="{ThemeResource FgPrimary}"/>
+    </Style>
+
+    <Style x:Key="TextSubtle" TargetType="TextBlock" BasedOn="{StaticResource TextBody}">
+        <Setter Property="Foreground" Value="{ThemeResource FgSecondary}"/>
+    </Style>
+
+    <Style x:Key="TextCaption" TargetType="TextBlock">
+        <Setter Property="FontFamily" Value="{ThemeResource FontSans}"/>
+        <Setter Property="FontSize" Value="{ThemeResource TextCaptionSize}"/>
+        <Setter Property="FontWeight" Value="Medium"/>
+        <Setter Property="Foreground" Value="{ThemeResource FgTertiary}"/>
+        <Setter Property="CharacterSpacing" Value="80"/>
+    </Style>
+
+    <Style x:Key="TextMono" TargetType="TextBlock">
+        <Setter Property="FontFamily" Value="{ThemeResource FontMono}"/>
+        <Setter Property="FontSize" Value="{ThemeResource TextMonoSize}"/>
+        <Setter Property="Foreground" Value="{ThemeResource FgSecondary}"/>
+    </Style>
+
+    <!-- ════════════ Button hierarchy ════════════
+         Primary  — single per surface, the brand action.    Cyan fill, near-black text.
+         Secondary — common operator actions.                Transparent + bordered.
+         Tertiary  — inline dismissals, low-frequency.        Text-only.
+         Destructive — Stop / Leave / Delete.                Coral border + text.
+    -->
+
+    <Style x:Key="ButtonPrimary" TargetType="Button">
+        <Setter Property="FontFamily" Value="{ThemeResource FontSans}"/>
+        <Setter Property="FontSize" Value="{ThemeResource TextBodySize}"/>
+        <Setter Property="FontWeight" Value="SemiBold"/>
+        <Setter Property="Background" Value="{ThemeResource AccentCyanSurface}"/>
+        <Setter Property="BorderBrush" Value="{ThemeResource AccentCyanSurface}"/>
+        <Setter Property="Foreground" Value="{ThemeResource FgOnAccent}"/>
+        <Setter Property="BorderThickness" Value="1"/>
+        <Setter Property="Padding" Value="16,8"/>
+        <Setter Property="CornerRadius" Value="{ThemeResource RadiusM}"/>
+        <Setter Property="HorizontalAlignment" Value="Stretch"/>
+        <Setter Property="HorizontalContentAlignment" Value="Center"/>
+        <Setter Property="VerticalContentAlignment" Value="Center"/>
+    </Style>
+
+    <Style x:Key="ButtonSecondary" TargetType="Button">
+        <Setter Property="FontFamily" Value="{ThemeResource FontSans}"/>
+        <Setter Property="FontSize" Value="{ThemeResource TextBodySize}"/>
+        <Setter Property="FontWeight" Value="Medium"/>
+        <Setter Property="Background" Value="Transparent"/>
+        <Setter Property="BorderBrush" Value="{ThemeResource BorderStrong}"/>
+        <Setter Property="Foreground" Value="{ThemeResource FgPrimary}"/>
+        <Setter Property="BorderThickness" Value="1"/>
+        <Setter Property="Padding" Value="14,7"/>
+        <Setter Property="CornerRadius" Value="{ThemeResource RadiusM}"/>
+        <Setter Property="HorizontalContentAlignment" Value="Center"/>
+        <Setter Property="VerticalContentAlignment" Value="Center"/>
+    </Style>
+
+    <Style x:Key="ButtonTertiary" TargetType="Button">
+        <Setter Property="FontFamily" Value="{ThemeResource FontSans}"/>
+        <Setter Property="FontSize" Value="{ThemeResource TextBodySize}"/>
+        <Setter Property="FontWeight" Value="Medium"/>
+        <Setter Property="Background" Value="Transparent"/>
+        <Setter Property="BorderBrush" Value="Transparent"/>
+        <Setter Property="Foreground" Value="{ThemeResource FgSecondary}"/>
+        <Setter Property="BorderThickness" Value="0"/>
+        <Setter Property="Padding" Value="10,6"/>
+        <Setter Property="CornerRadius" Value="{ThemeResource RadiusM}"/>
+    </Style>
+
+    <Style x:Key="ButtonDestructive" TargetType="Button" BasedOn="{StaticResource ButtonSecondary}">
+        <Setter Property="BorderBrush" Value="{ThemeResource AccentCoral}"/>
+        <Setter Property="Foreground" Value="{ThemeResource AccentCoral}"/>
+    </Style>
+
+    <!-- Title-bar caption buttons. 46x32 to match Windows 11 standard. The
+         close button gets a coral-red hover treatment via VSM override
+         (handled per-button inline since WinUI 3's default Close-button
+         red is the wrong red for our palette). -->
+    <Style x:Key="ButtonCaption" TargetType="Button">
+        <Setter Property="Background" Value="Transparent"/>
+        <Setter Property="BorderBrush" Value="Transparent"/>
+        <Setter Property="BorderThickness" Value="0"/>
+        <Setter Property="Foreground" Value="{ThemeResource FgPrimary}"/>
+        <Setter Property="Width" Value="46"/>
+        <Setter Property="Height" Value="32"/>
+        <Setter Property="Padding" Value="0"/>
+        <Setter Property="CornerRadius" Value="0"/>
+        <Setter Property="HorizontalContentAlignment" Value="Center"/>
+        <Setter Property="VerticalContentAlignment" Value="Center"/>
+    </Style>
+
+    <!-- Rail icon button. Vertical-square 48x48 with rounded fill on hover.
+         Used in the left rail; the icon (FontIcon) sits inside as Content. -->
+    <Style x:Key="ButtonRailIcon" TargetType="Button">
+        <Setter Property="Background" Value="Transparent"/>
+        <Setter Property="BorderBrush" Value="Transparent"/>
+        <Setter Property="BorderThickness" Value="0"/>
+        <Setter Property="Foreground" Value="{ThemeResource FgSecondary}"/>
+        <Setter Property="Width" Value="48"/>
+        <Setter Property="Height" Value="48"/>
+        <Setter Property="Margin" Value="0,4"/>
+        <Setter Property="Padding" Value="0"/>
+        <Setter Property="CornerRadius" Value="{ThemeResource RadiusM}"/>
+        <Setter Property="HorizontalContentAlignment" Value="Center"/>
+        <Setter Property="VerticalContentAlignment" Value="Center"/>
+    </Style>
+
+    <!-- ════════════ Card / Pill / Status containers ════════════ -->
+
+    <Style x:Key="CardBorder" TargetType="Border">
+        <Setter Property="Background" Value="{ThemeResource BgSurface}"/>
+        <Setter Property="BorderBrush" Value="{ThemeResource BorderSubtle}"/>
+        <Setter Property="BorderThickness" Value="1"/>
+        <Setter Property="CornerRadius" Value="{ThemeResource RadiusL}"/>
+        <Setter Property="Padding" Value="16"/>
+    </Style>
+
+    <Style x:Key="PillBorder" TargetType="Border">
+        <Setter Property="Background" Value="{ThemeResource BgElevated}"/>
+        <Setter Property="CornerRadius" Value="{ThemeResource RadiusPill}"/>
+        <Setter Property="Padding" Value="10,4"/>
+        <Setter Property="HorizontalAlignment" Value="Left"/>
+    </Style>
+
+</ResourceDictionary>
diff --git a/src/TeamsISO.App.WinUI/Themes/Tokens.xaml b/src/TeamsISO.App.WinUI/Themes/Tokens.xaml
new file mode 100644
index 0000000..0b35022
--- /dev/null
+++ b/src/TeamsISO.App.WinUI/Themes/Tokens.xaml
@@ -0,0 +1,194 @@
+<?xml version="1.0" encoding="utf-8"?>
+<ResourceDictionary
+    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
+
+    <!--
+        TeamsISO design tokens — Wild Dragon brand × redesigned IA.
+
+        Color tokens live inside ResourceDictionary.ThemeDictionaries so
+        {ThemeResource} consumers swap automatically when RequestedTheme
+        flips (no app restart, no flicker). Brushes are paired per theme
+        because Color resolution is theme-scoped.
+
+        Spacing, radii, and typography tokens are theme-agnostic and live
+        at the top level.
+
+        Token naming mirrors DESIGN.md. The dark palette is the canonical
+        reference; the light palette inverts the value scale while
+        preserving brand recognition (cyan-tinted off-whites, not pure
+        white surfaces).
+    -->
+
+    <ResourceDictionary.ThemeDictionaries>
+
+        <!-- ════════════ DARK ════════════ -->
+        <ResourceDictionary x:Key="Default">
+
+            <!-- Surfaces -->
+            <Color x:Key="BgCanvasColor">#FF0A0A0A</Color>
+            <Color x:Key="BgRailColor">#FF080808</Color>
+            <Color x:Key="BgSurfaceColor">#FF141416</Color>
+            <Color x:Key="BgElevatedColor">#FF1C1C1F</Color>
+            <Color x:Key="BgHoverColor">#FF26272B</Color>
+            <Color x:Key="BgActiveColor">#FF33343A</Color>
+
+            <!-- Borders -->
+            <Color x:Key="BorderSubtleColor">#FF26272B</Color>
+            <Color x:Key="BorderStrongColor">#FF3A3B40</Color>
+
+            <!-- Text -->
+            <Color x:Key="FgPrimaryColor">#FFF4F4F6</Color>
+            <Color x:Key="FgSecondaryColor">#FFA3A4AA</Color>
+            <Color x:Key="FgTertiaryColor">#FF6B6C72</Color>
+            <Color x:Key="FgDisabledColor">#FF404145</Color>
+            <Color x:Key="FgOnAccentColor">#FF0A0A0A</Color>
+
+            <!-- Accents (context-aware) -->
+            <Color x:Key="AccentCyanSurfaceColor">#FF97EDF0</Color>
+            <Color x:Key="AccentCyanTextColor">#FF97EDF0</Color>
+            <Color x:Key="AccentCyanHoverColor">#FFB5F2F4</Color>
+            <Color x:Key="AccentCyanMutedColor">#FF1B3537</Color>
+
+            <Color x:Key="AccentCoralColor">#FFFB819C</Color>
+            <Color x:Key="AccentCoralBgColor">#FF3A1922</Color>
+
+            <Color x:Key="StatusLiveColor">#FF4ADE80</Color>
+            <Color x:Key="StatusLiveBgColor">#FF13261A</Color>
+            <Color x:Key="StatusWarnColor">#FFFBBF24</Color>
+            <Color x:Key="StatusWarnBgColor">#FF3A2E12</Color>
+
+            <!-- Brushes — one per Color, used by consumers via {ThemeResource} -->
+            <SolidColorBrush x:Key="BgCanvas" Color="{ThemeResource BgCanvasColor}"/>
+            <SolidColorBrush x:Key="BgRail" Color="{ThemeResource BgRailColor}"/>
+            <SolidColorBrush x:Key="BgSurface" Color="{ThemeResource BgSurfaceColor}"/>
+            <SolidColorBrush x:Key="BgElevated" Color="{ThemeResource BgElevatedColor}"/>
+            <SolidColorBrush x:Key="BgHover" Color="{ThemeResource BgHoverColor}"/>
+            <SolidColorBrush x:Key="BgActive" Color="{ThemeResource BgActiveColor}"/>
+
+            <SolidColorBrush x:Key="BorderSubtle" Color="{ThemeResource BorderSubtleColor}"/>
+            <SolidColorBrush x:Key="BorderStrong" Color="{ThemeResource BorderStrongColor}"/>
+
+            <SolidColorBrush x:Key="FgPrimary" Color="{ThemeResource FgPrimaryColor}"/>
+            <SolidColorBrush x:Key="FgSecondary" Color="{ThemeResource FgSecondaryColor}"/>
+            <SolidColorBrush x:Key="FgTertiary" Color="{ThemeResource FgTertiaryColor}"/>
+            <SolidColorBrush x:Key="FgDisabled" Color="{ThemeResource FgDisabledColor}"/>
+            <SolidColorBrush x:Key="FgOnAccent" Color="{ThemeResource FgOnAccentColor}"/>
+
+            <SolidColorBrush x:Key="AccentCyanSurface" Color="{ThemeResource AccentCyanSurfaceColor}"/>
+            <SolidColorBrush x:Key="AccentCyanText" Color="{ThemeResource AccentCyanTextColor}"/>
+            <SolidColorBrush x:Key="AccentCyanHover" Color="{ThemeResource AccentCyanHoverColor}"/>
+            <SolidColorBrush x:Key="AccentCyanMuted" Color="{ThemeResource AccentCyanMutedColor}"/>
+
+            <SolidColorBrush x:Key="AccentCoral" Color="{ThemeResource AccentCoralColor}"/>
+            <SolidColorBrush x:Key="AccentCoralBg" Color="{ThemeResource AccentCoralBgColor}"/>
+
+            <SolidColorBrush x:Key="StatusLive" Color="{ThemeResource StatusLiveColor}"/>
+            <SolidColorBrush x:Key="StatusLiveBg" Color="{ThemeResource StatusLiveBgColor}"/>
+            <SolidColorBrush x:Key="StatusWarn" Color="{ThemeResource StatusWarnColor}"/>
+            <SolidColorBrush x:Key="StatusWarnBg" Color="{ThemeResource StatusWarnBgColor}"/>
+
+        </ResourceDictionary>
+
+        <!-- ════════════ LIGHT ════════════ -->
+        <ResourceDictionary x:Key="Light">
+
+            <!-- Surfaces — cyan-tinted off-whites; not pure white -->
+            <Color x:Key="BgCanvasColor">#FFFAFAFB</Color>
+            <Color x:Key="BgRailColor">#FFF0F1F3</Color>
+            <Color x:Key="BgSurfaceColor">#FFFFFFFF</Color>
+            <Color x:Key="BgElevatedColor">#FFFFFFFF</Color>
+            <Color x:Key="BgHoverColor">#FFECEEF1</Color>
+            <Color x:Key="BgActiveColor">#FFE0E3E7</Color>
+
+            <!-- Borders -->
+            <Color x:Key="BorderSubtleColor">#FFE5E7EB</Color>
+            <Color x:Key="BorderStrongColor">#FFD1D5DA</Color>
+
+            <!-- Text -->
+            <Color x:Key="FgPrimaryColor">#FF0A0A0A</Color>
+            <Color x:Key="FgSecondaryColor">#FF4A4B50</Color>
+            <Color x:Key="FgTertiaryColor">#FF71747A</Color>
+            <Color x:Key="FgDisabledColor">#FFB3B6BC</Color>
+            <Color x:Key="FgOnAccentColor">#FF0A0A0A</Color>
+
+            <!-- Accents — surface fill stays bright cyan; text variant darkens for AA -->
+            <Color x:Key="AccentCyanSurfaceColor">#FF97EDF0</Color>
+            <Color x:Key="AccentCyanTextColor">#FF0E7C82</Color>
+            <Color x:Key="AccentCyanHoverColor">#FF0890A0</Color>
+            <Color x:Key="AccentCyanMutedColor">#FFE6F8F9</Color>
+
+            <Color x:Key="AccentCoralColor">#FFD43E5C</Color>
+            <Color x:Key="AccentCoralBgColor">#FFFDECF0</Color>
+
+            <Color x:Key="StatusLiveColor">#FF15803D</Color>
+            <Color x:Key="StatusLiveBgColor">#FFDCFCE7</Color>
+            <Color x:Key="StatusWarnColor">#FFB45309</Color>
+            <Color x:Key="StatusWarnBgColor">#FFFEF3C7</Color>
+
+            <SolidColorBrush x:Key="BgCanvas" Color="{ThemeResource BgCanvasColor}"/>
+            <SolidColorBrush x:Key="BgRail" Color="{ThemeResource BgRailColor}"/>
+            <SolidColorBrush x:Key="BgSurface" Color="{ThemeResource BgSurfaceColor}"/>
+            <SolidColorBrush x:Key="BgElevated" Color="{ThemeResource BgElevatedColor}"/>
+            <SolidColorBrush x:Key="BgHover" Color="{ThemeResource BgHoverColor}"/>
+            <SolidColorBrush x:Key="BgActive" Color="{ThemeResource BgActiveColor}"/>
+
+            <SolidColorBrush x:Key="BorderSubtle" Color="{ThemeResource BorderSubtleColor}"/>
+            <SolidColorBrush x:Key="BorderStrong" Color="{ThemeResource BorderStrongColor}"/>
+
+            <SolidColorBrush x:Key="FgPrimary" Color="{ThemeResource FgPrimaryColor}"/>
+            <SolidColorBrush x:Key="FgSecondary" Color="{ThemeResource FgSecondaryColor}"/>
+            <SolidColorBrush x:Key="FgTertiary" Color="{ThemeResource FgTertiaryColor}"/>
+            <SolidColorBrush x:Key="FgDisabled" Color="{ThemeResource FgDisabledColor}"/>
+            <SolidColorBrush x:Key="FgOnAccent" Color="{ThemeResource FgOnAccentColor}"/>
+
+            <SolidColorBrush x:Key="AccentCyanSurface" Color="{ThemeResource AccentCyanSurfaceColor}"/>
+            <SolidColorBrush x:Key="AccentCyanText" Color="{ThemeResource AccentCyanTextColor}"/>
+            <SolidColorBrush x:Key="AccentCyanHover" Color="{ThemeResource AccentCyanHoverColor}"/>
+            <SolidColorBrush x:Key="AccentCyanMuted" Color="{ThemeResource AccentCyanMutedColor}"/>
+
+            <SolidColorBrush x:Key="AccentCoral" Color="{ThemeResource AccentCoralColor}"/>
+            <SolidColorBrush x:Key="AccentCoralBg" Color="{ThemeResource AccentCoralBgColor}"/>
+
+            <SolidColorBrush x:Key="StatusLive" Color="{ThemeResource StatusLiveColor}"/>
+            <SolidColorBrush x:Key="StatusLiveBg" Color="{ThemeResource StatusLiveBgColor}"/>
+            <SolidColorBrush x:Key="StatusWarn" Color="{ThemeResource StatusWarnColor}"/>
+            <SolidColorBrush x:Key="StatusWarnBg" Color="{ThemeResource StatusWarnBgColor}"/>
+
+        </ResourceDictionary>
+
+    </ResourceDictionary.ThemeDictionaries>
+
+    <!-- ════════════ SPACING (8px grid) — theme-agnostic ════════════ -->
+    <x:Double x:Key="SpaceXS">4</x:Double>
+    <x:Double x:Key="SpaceS">8</x:Double>
+    <x:Double x:Key="SpaceM">12</x:Double>
+    <x:Double x:Key="SpaceL">16</x:Double>
+    <x:Double x:Key="SpaceXL">24</x:Double>
+    <x:Double x:Key="SpaceXXL">32</x:Double>
+    <x:Double x:Key="SpaceXXXL">48</x:Double>
+
+    <!-- ════════════ RADII ════════════ -->
+    <CornerRadius x:Key="RadiusS">6</CornerRadius>
+    <CornerRadius x:Key="RadiusM">8</CornerRadius>
+    <CornerRadius x:Key="RadiusL">12</CornerRadius>
+    <CornerRadius x:Key="RadiusPill">999</CornerRadius>
+
+    <!-- ════════════ TYPOGRAPHY ════════════ -->
+    <!--
+        WinUI 3 font URIs use ms-appx, not WPF's pack://. The "#Inter" suffix
+        is the font's family name as declared in the .ttf's name table —
+        without it, the font loads as a generic font and falls back to the
+        system default.
+    -->
+    <FontFamily x:Key="FontSans">ms-appx:///Assets/Fonts/Inter.ttf#Inter</FontFamily>
+    <FontFamily x:Key="FontMono">ms-appx:///Assets/Fonts/JetBrainsMono.ttf#JetBrains Mono</FontFamily>
+
+    <x:Double x:Key="TextDisplaySize">22</x:Double>
+    <x:Double x:Key="TextTitleSize">18</x:Double>
+    <x:Double x:Key="TextHeadingSize">14</x:Double>
+    <x:Double x:Key="TextBodySize">13</x:Double>
+    <x:Double x:Key="TextCaptionSize">11</x:Double>
+    <x:Double x:Key="TextMonoSize">12</x:Double>
+
+</ResourceDictionary>
diff --git a/src/TeamsISO.App.WinUI/Views/MainWindow.xaml b/src/TeamsISO.App.WinUI/Views/MainWindow.xaml
new file mode 100644
index 0000000..72289b5
--- /dev/null
+++ b/src/TeamsISO.App.WinUI/Views/MainWindow.xaml
@@ -0,0 +1,12 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Window
+    x:Class="TeamsISO.App.WinUI.Views.MainWindow"
+    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
+    <Grid Background="{ThemeResource BgCanvas}">
+        <TextBlock Style="{StaticResource TextTitle}"
+                   Text="TeamsISO — WinUI 3 host scaffold"
+                   HorizontalAlignment="Center"
+                   VerticalAlignment="Center"/>
+    </Grid>
+</Window>
diff --git a/src/TeamsISO.App.WinUI/Views/MainWindow.xaml.cs b/src/TeamsISO.App.WinUI/Views/MainWindow.xaml.cs
new file mode 100644
index 0000000..ee66b88
--- /dev/null
+++ b/src/TeamsISO.App.WinUI/Views/MainWindow.xaml.cs
@@ -0,0 +1,12 @@
+using Microsoft.UI.Xaml;
+
+namespace TeamsISO.App.WinUI.Views;
+
+public sealed partial class MainWindow : Window
+{
+    public MainWindow()
+    {
+        InitializeComponent();
+        Title = "TeamsISO";
+    }
+}
diff --git a/src/TeamsISO.App.WinUI/app.manifest b/src/TeamsISO.App.WinUI/app.manifest
new file mode 100644
index 0000000..5dbdde4
--- /dev/null
+++ b/src/TeamsISO.App.WinUI/app.manifest
@@ -0,0 +1,32 @@
+<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
+<assembly manifestVersion="1.0" xmlns="urn:schemas-microsoft-com:asm.v1">
+  <assemblyIdentity version="1.0.0.0" name="TeamsISO.App.WinUI"/>
+  <trustInfo xmlns="urn:schemas-microsoft-com:asm.v3">
+    <security>
+      <requestedPrivileges xmlns="urn:schemas-microsoft-com:asm.v3">
+        <!-- TeamsISO is a normal-trust desktop app; no UAC elevation needed.
+             Network listens (control surface :9755 and OSC :9000) bind to
+             127.0.0.1 only, which doesn't require admin. -->
+        <requestedExecutionLevel level="asInvoker" uiAccess="false"/>
+      </requestedPrivileges>
+    </security>
+  </trustInfo>
+  <compatibility xmlns="urn:schemas-microsoft-com:compatibility.v1">
+    <application>
+      <!-- Win10 1809 (17763) is the floor — same as TargetPlatformMinVersion. -->
+      <supportedOS Id="{8e0f7a12-bfb3-4fe8-b9a5-48fd50a15a9a}"/>
+      <supportedOS Id="{1f676c76-80e1-4239-95bb-83d0f6d0da78}"/>
+      <supportedOS Id="{4a2f28e3-53b9-4441-ba9c-d69d4a4a6e38}"/>
+      <supportedOS Id="{35138b9a-5d96-4fbd-8e2d-a2440225f93a}"/>
+      <supportedOS Id="{e2011457-1546-43c5-a5fe-008deee3d3f0}"/>
+    </application>
+  </compatibility>
+  <application xmlns="urn:schemas-microsoft-com:asm.v3">
+    <windowsSettings>
+      <dpiAware xmlns="http://schemas.microsoft.com/SMI/2005/WindowsSettings">true/PM</dpiAware>
+      <dpiAwareness xmlns="http://schemas.microsoft.com/SMI/2016/WindowsSettings">PerMonitorV2, PerMonitor</dpiAwareness>
+      <!-- Crisp text on high-DPI broadcast monitors. -->
+      <gdiScaling xmlns="http://schemas.microsoft.com/SMI/2017/WindowsSettings">true</gdiScaling>
+    </windowsSettings>
+  </application>
+</assembly>