diff --git a/NativeMethods.cs b/NativeMethods.cs
index 78ef4b7..5321aab 100644
--- a/NativeMethods.cs
+++ b/NativeMethods.cs
@@ -2,6 +2,7 @@ using System;
 using System.Runtime.InteropServices;
 using System.Threading;
 using System.Threading.Tasks;
+using Windows.Media.Control;
 
 namespace TimerApp
 {
@@ -59,12 +60,15 @@ namespace TimerApp
         private static bool _mediaPlaying;
         private static long _mediaLastUpdateMs = -1;
         private static int _mediaUpdateInProgress;
+        private const int MediaCacheWhenPlayingMs = 500;
+        private const int MediaCacheWhenNotPlayingMs = 1200;
 
         private static void EnsureMediaPlaybackStatusFresh()
         {
             long now = Environment.TickCount64;
             long last = Interlocked.Read(ref _mediaLastUpdateMs);
-            if (last >= 0 && now - last < 3000)
+            int cacheMs = Volatile.Read(ref _mediaPlaying) ? MediaCacheWhenPlayingMs : MediaCacheWhenNotPlayingMs;
+            if (last >= 0 && now - last < cacheMs)
             {
                 return;
             }
@@ -74,13 +78,24 @@ namespace TimerApp
                 return;
             }
 
-            _ = Task.Run(async () =>
+            _ = Task.Run(() =>
             {
                 bool playing = false;
                 try
                 {
-                    await Task.Yield();
-                    playing = TryIsAudioPlaying();
+                    playing = RunOnStaThread(() =>
+                    {
+                        try
+                        {
+                            return TryIsSystemMediaSessionPlayingAsync().GetAwaiter().GetResult();
+                        }
+                        catch
+                        {
+                            return false;
+                        }
+                    });
+
+                    playing = playing || TryIsAudioPlaying();
                 }
                 catch
                 {
@@ -96,6 +111,11 @@ namespace TimerApp
         }
 
         private static bool TryIsAudioPlaying()
+        {
+            return TryIsAudioPlaying(ERole.eMultimedia) || TryIsAudioPlaying(ERole.eConsole) || TryIsAudioPlaying(ERole.eCommunications);
+        }
+
+        private static bool TryIsAudioPlaying(ERole role)
         {
             object? deviceEnumeratorObj = null;
             IMMDeviceEnumerator? deviceEnumerator = null;
@@ -115,7 +135,7 @@ namespace TimerApp
                     return false;
                 deviceEnumerator = (IMMDeviceEnumerator)deviceEnumeratorObj;
 
-                Marshal.ThrowExceptionForHR(deviceEnumerator.GetDefaultAudioEndpoint(EDataFlow.eRender, ERole.eMultimedia, out device));
+                Marshal.ThrowExceptionForHR(deviceEnumerator.GetDefaultAudioEndpoint(EDataFlow.eRender, role, out device));
 
                 Guid iid = typeof(IAudioSessionManager2).GUID;
                 Marshal.ThrowExceptionForHR(device.Activate(ref iid, CLSCTX.CLSCTX_ALL, IntPtr.Zero, out sessionManagerObj));
@@ -141,7 +161,7 @@ namespace TimerApp
                         if (sessionControl is IAudioMeterInformation meter)
                         {
                             Marshal.ThrowExceptionForHR(meter.GetPeakValue(out float peak));
-                            if (peak > 0.001f)
+                            if (peak > 0.0001f)
                                 return true;
                         }
                         else
@@ -170,6 +190,82 @@ namespace TimerApp
             }
         }
 
+        private static async Task<bool> TryIsSystemMediaSessionPlayingAsync()
+        {
+            try
+            {
+                GlobalSystemMediaTransportControlsSessionManager manager = await GlobalSystemMediaTransportControlsSessionManager.RequestAsync();
+
+                GlobalSystemMediaTransportControlsSession? current = manager.GetCurrentSession();
+                if (IsPlaying(current))
+                {
+                    return true;
+                }
+
+                foreach (GlobalSystemMediaTransportControlsSession session in manager.GetSessions())
+                {
+                    if (IsPlaying(session))
+                    {
+                        return true;
+                    }
+                }
+
+                return false;
+            }
+            catch
+            {
+                return false;
+            }
+        }
+
+        private static bool IsPlaying(GlobalSystemMediaTransportControlsSession? session)
+        {
+            if (session is null)
+            {
+                return false;
+            }
+
+            try
+            {
+                GlobalSystemMediaTransportControlsSessionPlaybackInfo? info = session.GetPlaybackInfo();
+                return info is not null && info.PlaybackStatus == GlobalSystemMediaTransportControlsSessionPlaybackStatus.Playing;
+            }
+            catch
+            {
+                return false;
+            }
+        }
+
+        private static bool RunOnStaThread(Func<bool> action)
+        {
+            bool result = false;
+            Exception? error = null;
+
+            Thread thread = new Thread(() =>
+            {
+                try
+                {
+                    result = action();
+                }
+                catch (Exception ex)
+                {
+                    error = ex;
+                }
+            });
+
+            thread.IsBackground = true;
+            thread.SetApartmentState(ApartmentState.STA);
+            thread.Start();
+            thread.Join();
+
+            if (error is not null)
+            {
+                return false;
+            }
+
+            return result;
+        }
+
         private static readonly Guid CLSID_MMDeviceEnumerator = new Guid("BCDE0395-E52F-467C-8E3D-C4579291692E");
 
         private enum EDataFlow
@@ -244,8 +340,15 @@ namespace TimerApp
         [InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
         private interface IAudioSessionControl
         {
-            int NotImpl1();
             int GetState(out AudioSessionState state);
+            int NotImpl1();
+            int NotImpl2();
+            int NotImpl3();
+            int NotImpl4();
+            int NotImpl5();
+            int NotImpl6();
+            int NotImpl7();
+            int NotImpl8();
         }
 
         [ComImport]
diff --git a/README.md b/README.md
index 7e66804..8491a8b 100644
--- a/README.md
+++ b/README.md
@@ -36,6 +36,17 @@
 - 休息倒计时以“秒级稳定推进”为目标
   - 设计目的：让休息提示的倒计时更平滑、更可预期
 
+## 媒体播放检测（视频/音频）
+
+- 目标：当你在“播放视频/音频”时，倾向不推进工作计时，避免把被动观看算作连续高强度工作
+- 判定策略（由强到弱）：
+  - 系统媒体会话（SMTC/GSMTC）：当播放器/浏览器接入系统媒体控制时，可直接识别“播放/暂停”
+  - 音频会话峰值兜底：当系统媒体会话不可用时，通过默认音频设备的会话峰值判断是否正在输出声音
+- 响应延迟：
+  - 计时器自身按 1 秒节拍检查一次
+  - 媒体状态会做短缓存刷新：播放中约 0.5 秒刷新、未播放约 1.2 秒刷新
+  - 实际体验通常是“暂停后约 1 秒左右恢复计时”
+
 ## 休息提醒（强提示的边界）
 
 - 休息阶段会出现遮罩式提醒，核心是“让你意识到现在该休息了”
@@ -81,3 +92,29 @@
 
 - 将“工作/休息时长、空闲判定阈值、主题偏好”等作为可持久化设置，保证重启后仍保持用户习惯
 - 同时考虑“安装使用”和“解压即用”的便携形态：便携形态下更倾向把设置跟随程序一起携带，便于拷贝迁移
+
+## 系统要求
+
+- Windows 10 2004（版本号 19041）及以上：媒体播放检测依赖系统媒体会话相关 API
+
+## 编译与发布
+
+- 开发环境要求
+  - Windows（WinForms 桌面程序）
+  - .NET SDK 9（项目目标框架：net9.0-windows10.0.19041.0）
+- 本地编译
+  - Debug：
+    - `dotnet build`
+  - Release：
+    - `dotnet build -c Release`
+- 本地运行
+  - `dotnet run`
+- 便携版打包（生成 dist zip）
+  - PowerShell：
+    - `.\scripts\publish-portable.ps1`
+    - 自包含（目标机无需安装 .NET Desktop Runtime）：
+      - `.\scripts\publish-portable.ps1 -SelfContained $true`
+    - 指定架构（示例：x64）：
+      - `.\scripts\publish-portable.ps1 -Rid win-x64`
+  - CMD：
+    - `.\scripts\publish-portable.cmd`
diff --git a/TimerApp.csproj b/TimerApp.csproj
index a3de757..44f119f 100644
--- a/TimerApp.csproj
+++ b/TimerApp.csproj
@@ -2,7 +2,7 @@
 
   <PropertyGroup>
     <OutputType>WinExe</OutputType>
-    <TargetFramework>net9.0-windows</TargetFramework>
+    <TargetFramework>net9.0-windows10.0.19041.0</TargetFramework>
     <Nullable>enable</Nullable>
     <UseWindowsForms>true</UseWindowsForms>
     <ImplicitUsings>enable</ImplicitUsings>