diff --git a/client/app.go b/client/app.go
index 7399751..773d125 100644
--- a/client/app.go
+++ b/client/app.go
@@ -975,18 +975,21 @@ func (a *App) connectWS() {
 			case "chat:message":
 				senderRole, _ := msg.Data["senderRole"].(string)
 				if senderRole == "staff" {
+					from := "Giảng viên"
+					if n, ok := msg.Data["staffName"].(string); ok && n != "" {
+						from = n
+					}
+					preview := ""
+					if b, ok := msg.Data["body"].(string); ok {
+						preview = b
+					}
 					if staffVal, ok := msg.Data["staffId"].(float64); ok {
 						a.mu.Lock()
 						a.replyStaffID = uint(staffVal)
 						a.chatUnread++
-						unread := a.chatUnread
 						a.mu.Unlock()
-						runtime.EventsEmit(a.ctx, "chat:notify", map[string]any{
-							"unread":  unread,
-							"preview": msg.Data["body"],
-							"from":    msg.Data["staffName"],
-						})
 					}
+					a.alertChatIncoming(from, preview)
 				}
 				runtime.EventsEmit(a.ctx, "chat:message", msg.Data)
 			}
@@ -1059,6 +1062,32 @@ func (a *App) stopScreenshotStream() {
 	log.Println("[WS] Screenshot screen-streaming stopped.")
 }
 
+func (a *App) alertChatIncoming(from, preview string) {
+	if preview == "" {
+		preview = "Bạn có tin nhắn mới"
+	}
+	if len(preview) > 120 {
+		preview = preview[:120] + "…"
+	}
+	winapi.PlayNotifySound()
+	winapi.ActivateAppWindow("Simple Care")
+	runtime.WindowUnminimise(a.ctx)
+	runtime.WindowShow(a.ctx)
+	a.mu.Lock()
+	unread := a.chatUnread
+	staffID := a.replyStaffID
+	a.mu.Unlock()
+	runtime.EventsEmit(a.ctx, "chat:notify", map[string]any{
+		"unread":  unread,
+		"preview": preview,
+		"from":    from,
+		"staffId": staffID,
+	})
+}
+
+// UnlockChatAudio — gọi từ UI sau lần click đầu để mở khóa Web Audio (dự phòng)
+func (a *App) UnlockChatAudio() {}
+
 func (a *App) GetChatUnread() int {
 	a.mu.Lock()
 	defer a.mu.Unlock()
diff --git a/client/frontend/src/app.css b/client/frontend/src/app.css
index 1e30cf4..7295705 100644
--- a/client/frontend/src/app.css
+++ b/client/frontend/src/app.css
@@ -490,127 +490,148 @@ body {
   white-space: nowrap;
 }
 
-/* Student chat messenger */
+/* Student chat — modal 2 panel giống web */
 .student-chat-dock {
   position: fixed;
-  right: 12px;
-  bottom: 12px;
-  z-index: 1000;
+  right: 16px;
+  bottom: 16px;
+  z-index: 2000;
+  pointer-events: none;
 }
 
-.student-chat-toast {
-  position: absolute;
-  right: 0;
-  bottom: 64px;
-  width: 260px;
-  padding: 0.65rem 0.75rem;
-  border-radius: 10px;
-  background: #1e293b;
-  color: #fff;
-  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.28);
-  font-size: 0.78rem;
-  display: flex;
-  flex-direction: column;
-  gap: 0.2rem;
+.student-chat-dock > * {
+  pointer-events: auto;
 }
 
 .student-chat-fab {
   position: relative;
-  width: 48px;
-  height: 48px;
+  width: 50px;
+  height: 50px;
   border-radius: 50%;
   border: none;
   background: var(--accent);
   color: #fff;
   font-size: 1.15rem;
   cursor: pointer;
-  box-shadow: 0 6px 18px rgba(0, 0, 0, 0.25);
+  box-shadow: 0 6px 20px rgba(0, 0, 0, 0.28);
+}
+
+.student-chat-fab.is-hidden {
+  display: none;
+}
+
+.student-chat-fab--pulse {
+  animation: chat-fab-pulse 0.6s ease 2;
+}
+
+@keyframes chat-fab-pulse {
+  0%, 100% { transform: scale(1); }
+  50% { transform: scale(1.1); box-shadow: 0 0 0 8px rgba(187, 33, 38, 0.25); }
 }
 
 .student-chat-badge {
   position: absolute;
-  top: -2px;
-  right: -2px;
-  min-width: 16px;
-  height: 16px;
-  padding: 0 4px;
-  border-radius: 8px;
+  top: -3px;
+  right: -3px;
+  min-width: 18px;
+  height: 18px;
+  padding: 0 5px;
+  border-radius: 9px;
   background: #ef4444;
   color: #fff;
   font-size: 0.62rem;
   font-weight: 700;
-  line-height: 16px;
+  line-height: 18px;
 }
 
-.student-chat-messenger {
+.student-chat-modal {
+  display: none;
   position: absolute;
   right: 0;
-  bottom: 58px;
-  width: min(520px, calc(100vw - 24px));
-  height: min(400px, calc(100vh - 80px));
+  bottom: 60px;
+  width: min(560px, calc(100vw - 32px));
+  height: min(440px, calc(100vh - 100px));
   background: var(--bg-card);
   border: 1px solid var(--border-color);
   border-radius: 12px;
-  box-shadow: 0 12px 36px rgba(0, 0, 0, 0.3);
-  display: flex;
+  box-shadow: 0 16px 48px rgba(0, 0, 0, 0.38);
   flex-direction: column;
   overflow: hidden;
 }
 
-.student-chat-messenger-head {
+.student-chat-modal.is-open {
+  display: flex;
+}
+
+.student-chat-modal-head {
   display: flex;
-  justify-content: space-between;
   align-items: center;
-  padding: 0.55rem 0.7rem;
+  justify-content: space-between;
+  padding: 0.65rem 0.85rem;
   border-bottom: 1px solid var(--border-color);
-  font-size: 0.82rem;
   flex-shrink: 0;
+  font-size: 0.88rem;
 }
 
 .student-chat-close {
   border: none;
-  background: none;
+  background: transparent;
   color: var(--text-muted);
-  font-size: 1.1rem;
+  width: 30px;
+  height: 30px;
+  border-radius: 6px;
   cursor: pointer;
+  font-size: 1.25rem;
+  line-height: 1;
 }
 
-.student-chat-messenger-body {
-  display: flex;
+.student-chat-close:hover {
+  background: rgba(187, 33, 38, 0.12);
+  color: var(--accent);
+}
+
+.student-chat-modal-body {
   flex: 1;
   min-height: 0;
+  display: flex;
+  overflow: hidden;
 }
 
 .student-chat-sidebar {
-  width: 150px;
+  width: 200px;
   flex-shrink: 0;
   border-right: 1px solid var(--border-color);
   overflow-y: auto;
-  background: rgba(255, 255, 255, 0.02);
-  display: flex;
-  flex-direction: column;
+  overscroll-behavior: contain;
+  background: rgba(0, 0, 0, 0.06);
 }
 
-.student-chat-conv-btn {
+.student-chat-conv-row {
   width: 100%;
   text-align: left;
   border: none;
   background: transparent;
-  padding: 0.55rem 0.5rem;
+  padding: 0.7rem 0.75rem;
   cursor: pointer;
   border-bottom: 1px solid var(--border-color);
   color: var(--text-primary);
 }
 
-.student-chat-conv-btn.active {
+.student-chat-conv-row:hover {
+  background: rgba(255, 255, 255, 0.04);
+}
+
+.student-chat-conv-row.active {
   background: rgba(187, 33, 38, 0.12);
-  border-left: 2px solid var(--accent);
+  border-left: 3px solid var(--accent);
 }
 
 .student-chat-conv-name {
   display: flex;
   justify-content: space-between;
-  font-size: 0.72rem;
+  align-items: center;
+  gap: 0.35rem;
+  font-size: 0.78rem;
   font-weight: 600;
 }
 
@@ -621,29 +642,32 @@ body {
   border-radius: 8px;
   padding: 0 5px;
   font-size: 0.6rem;
+  font-weight: 700;
+  flex-shrink: 0;
 }
 
 .student-chat-conv-preview {
   display: block;
-  font-size: 0.65rem;
+  font-size: 0.7rem;
   color: var(--text-muted);
+  margin-top: 0.2rem;
   white-space: nowrap;
   overflow: hidden;
   text-overflow: ellipsis;
-  margin-top: 0.15rem;
 }
 
 .student-chat-thread {
   flex: 1;
+  min-width: 0;
   display: flex;
   flex-direction: column;
-  min-width: 0;
+  overflow: hidden;
 }
 
 .student-chat-thread-head {
-  padding: 0.45rem 0.65rem;
+  padding: 0.55rem 0.75rem;
   border-bottom: 1px solid var(--border-color);
-  font-size: 0.75rem;
+  font-size: 0.8rem;
   font-weight: 600;
   flex-shrink: 0;
 }
@@ -651,43 +675,38 @@ body {
 .student-chat-messages {
   flex: 1;
   overflow-y: auto;
-  padding: 0.55rem;
+  overscroll-behavior: contain;
+  padding: 0.65rem 0.75rem;
   display: flex;
   flex-direction: column;
   gap: 0.4rem;
-  background: rgba(0, 0, 0, 0.12);
+  background: rgba(0, 0, 0, 0.06);
 }
 
 .student-chat-empty {
-  font-size: 0.72rem;
+  font-size: 0.78rem;
   color: var(--text-muted);
   text-align: center;
-  padding: 1rem 0.5rem;
+  padding: 1.5rem 0.75rem;
 }
 
 .student-chat-bubble {
-  max-width: 88%;
-  font-size: 0.76rem;
+  max-width: 82%;
+  font-size: 0.8rem;
 }
 
 .student-chat-bubble--staff { align-self: flex-start; }
 .student-chat-bubble--student { align-self: flex-end; }
 
-.student-chat-label {
-  font-size: 0.6rem;
-  color: var(--text-muted);
-  margin-bottom: 0.1rem;
-}
-
 .student-chat-body {
-  padding: 0.4rem 0.55rem;
-  border-radius: 10px;
-  line-height: 1.35;
+  padding: 0.45rem 0.6rem;
+  border-radius: 12px;
+  line-height: 1.4;
   word-break: break-word;
 }
 
 .student-chat-bubble--staff .student-chat-body {
-  background: rgba(255, 255, 255, 0.06);
+  background: rgba(255, 255, 255, 0.08);
   border: 1px solid var(--border-color);
 }
 
@@ -697,33 +716,31 @@ body {
 }
 
 .student-chat-time {
-  font-size: 0.58rem;
+  font-size: 0.6rem;
   color: var(--text-muted);
-  margin-top: 0.1rem;
+  margin-top: 0.12rem;
+  padding: 0 0.2rem;
 }
 
 .student-chat-compose {
   display: flex;
-  gap: 0.35rem;
-  padding: 0.45rem 0.55rem;
+  gap: 0.45rem;
+  padding: 0.55rem 0.7rem;
   border-top: 1px solid var(--border-color);
   flex-shrink: 0;
+  background: var(--bg-card);
 }
 
 .student-chat-compose input {
   flex: 1;
-  font-size: 0.74rem;
-  padding: 0.4rem 0.5rem;
+  font-size: 0.8rem;
+  padding: 0.5rem 0.6rem;
   border-radius: 8px;
   border: 1px solid var(--border-color);
   background: var(--bg-base);
   color: var(--text-primary);
 }
 
-.student-chat-compose input:disabled {
-  opacity: 0.5;
-}
-
 .shifts-wrap {
   flex: 1;
   min-height: 0;
diff --git a/client/frontend/src/main.js b/client/frontend/src/main.js
index 0a69052..8f64d28 100644
--- a/client/frontend/src/main.js
+++ b/client/frontend/src/main.js
@@ -27,34 +27,8 @@ let chatOpen = false;
 let chatMessages = [];
 let chatConversations = [];
 let activeStaffId = 0;
-let chatAudioCtx = null;
-
-function playChatSound() {
-  try {
-    const Ctx = window.AudioContext || window.webkitAudioContext;
-    if (!chatAudioCtx) chatAudioCtx = new Ctx();
-    const ctx = chatAudioCtx;
-    if (ctx.state === 'suspended') ctx.resume();
-    const tone = (freq, start, dur) => {
-      const osc = ctx.createOscillator();
-      const gain = ctx.createGain();
-      osc.type = 'sine';
-      osc.frequency.value = freq;
-      gain.gain.setValueAtTime(0.0001, start);
-      gain.gain.exponentialRampToValueAtTime(0.15, start + 0.02);
-      gain.gain.exponentialRampToValueAtTime(0.0001, start + dur);
-      osc.connect(gain);
-      gain.connect(ctx.destination);
-      osc.start(start);
-      osc.stop(start + dur + 0.02);
-    };
-    const t = ctx.currentTime;
-    tone(880, t, 0.12);
-    tone(1174, t + 0.14, 0.14);
-  } catch {
-    /* ignore */
-  }
-}
+let lastRenderedMsgCount = 0;
+let bannerStaffId = 0;
 
 // Quản lý webcam
 let webcamStream = null;
@@ -82,15 +56,14 @@ function init() {
   window.runtime.EventsOn('chat:message', (data) => {
     updateChatBadge();
     loadChatConversations().catch(console.error);
-    if (chatOpen && activeStaffId) loadChatMessages(activeStaffId).catch(console.error);
-    if (data?.senderRole === 'staff') {
-      playChatSound();
+    if (chatOpen && activeStaffId) {
+      loadChatMessages(activeStaffId, true).catch(console.error);
     }
   });
   window.runtime.EventsOn('chat:notify', (data) => {
     updateChatBadge();
-    showChatToast(data);
-    playChatSound();
+    if (data?.staffId) bannerStaffId = Number(data.staffId);
+    pulseChatFab();
   });
   checkLogin();
 }
@@ -310,71 +283,85 @@ function ensureChatWidget() {
   wrap.id = 'student-chat-widget';
   wrap.className = 'student-chat-dock';
   wrap.innerHTML = `
-    <div class="student-chat-toast" id="student-chat-toast" hidden></div>
     <button type="button" class="student-chat-fab" id="student-chat-fab" title="Tin nhắn">
       💬<span class="student-chat-badge" id="student-chat-badge" hidden>0</span>
     </button>
-    <div class="student-chat-messenger" id="student-chat-messenger" hidden>
-      <header class="student-chat-messenger-head">
+    <div class="student-chat-modal" id="student-chat-modal">
+      <header class="student-chat-modal-head">
         <strong>Tin nhắn</strong>
-        <button type="button" class="student-chat-close" id="student-chat-close">×</button>
+        <button type="button" class="student-chat-close" id="student-chat-close" aria-label="Đóng">×</button>
       </header>
-      <div class="student-chat-messenger-body">
-        <aside class="student-chat-sidebar" id="student-chat-conv-list"></aside>
+      <div class="student-chat-modal-body">
+        <aside class="student-chat-sidebar" id="student-chat-sidebar"></aside>
         <section class="student-chat-thread">
           <div class="student-chat-thread-head" id="student-chat-thread-head">Chọn hội thoại</div>
-          <div class="student-chat-messages" id="student-chat-messages"></div>
+          <div class="student-chat-messages" id="student-chat-messages">
+            <div class="student-chat-empty">Chọn giảng viên bên trái để xem tin nhắn</div>
+          </div>
           <div class="student-chat-compose">
-            <input id="student-chat-input" placeholder="Nhập tin nhắn..." disabled />
-            <button type="button" class="btn btn-primary btn-sm" id="student-chat-send" disabled>Gửi</button>
+            <input id="student-chat-input" placeholder="Nhập tin nhắn..." />
+            <button type="button" class="btn btn-primary btn-sm" id="student-chat-send">Gửi</button>
           </div>
         </section>
       </div>
     </div>
   `;
   document.body.appendChild(wrap);
-  document.getElementById('student-chat-fab').addEventListener('click', toggleChat);
-  document.getElementById('student-chat-close').addEventListener('click', () => setChatOpen(false));
+
+  document.getElementById('student-chat-fab').addEventListener('click', () => setChatOpen(true));
+  document.getElementById('student-chat-close').addEventListener('click', (e) => {
+    e.preventDefault();
+    e.stopPropagation();
+    setChatOpen(false);
+  });
   document.getElementById('student-chat-send').addEventListener('click', sendStudentChat);
   document.getElementById('student-chat-input').addEventListener('keydown', (e) => {
     if (e.key === 'Enter') { e.preventDefault(); sendStudentChat(); }
   });
 }
 
-function showChatToast(data) {
-  const toast = document.getElementById('student-chat-toast');
-  if (!toast) return;
-  const from = data?.from || 'Giảng viên';
-  const preview = data?.preview || 'Bạn có tin nhắn mới';
-  toast.innerHTML = `<strong>${escapeHtml(from)}</strong><span>${escapeHtml(preview)}</span>`;
-  toast.hidden = false;
-  clearTimeout(showChatToast._t);
-  showChatToast._t = setTimeout(() => { toast.hidden = true; }, 5000);
+function pulseChatFab() {
+  const fab = document.getElementById('student-chat-fab');
+  if (!fab) return;
+  fab.classList.remove('student-chat-fab--pulse');
+  void fab.offsetWidth;
+  fab.classList.add('student-chat-fab--pulse');
 }
 
 function setChatOpen(open) {
   chatOpen = open;
-  const panel = document.getElementById('student-chat-messenger');
-  if (panel) panel.hidden = !open;
+  const modal = document.getElementById('student-chat-modal');
+  const fab = document.getElementById('student-chat-fab');
+  if (modal) modal.classList.toggle('is-open', open);
+  if (fab) fab.classList.toggle('is-hidden', open);
   if (open) {
-    loadChatConversations().catch(console.error);
-    if (activeStaffId) loadChatMessages(activeStaffId).catch(console.error);
+    loadChatConversations().then(() => {
+      const sid = bannerStaffId || activeStaffId || Number(chatConversations[0]?.staffId || 0);
+      if (sid) selectStaffChat(sid);
+    }).catch(console.error);
   }
 }
 
-function toggleChat() {
-  setChatOpen(!chatOpen);
+function selectStaffChat(staffId) {
+  if (!staffId) return;
+  activeStaffId = staffId;
+  const conv = chatConversations.find((c) => Number(c.staffId) === staffId);
+  const head = document.getElementById('student-chat-thread-head');
+  if (head) head.textContent = conv?.staffName || conv?.staffEmail || 'Giảng viên';
+  renderChatConversations();
+  loadChatMessages(staffId).catch(console.error);
 }
 
 async function loadChatConversations() {
   const rows = await window.go.main.App.GetChatConversations();
   chatConversations = Array.isArray(rows) ? rows : [];
-  renderChatConversations();
+  if (chatOpen) renderChatConversations();
   updateChatBadge();
+  return chatConversations;
 }
 
 function renderChatConversations() {
-  const list = document.getElementById('student-chat-conv-list');
+  const list = document.getElementById('student-chat-sidebar');
   if (!list) return;
   if (!chatConversations.length) {
     list.innerHTML = '<div class="student-chat-empty">Chưa có tin nhắn</div>';
@@ -385,55 +372,47 @@ function renderChatConversations() {
     const unread = Number(c.unread || 0);
     const active = sid === activeStaffId ? ' active' : '';
     const name = escapeHtml(c.staffName || c.staffEmail || 'Giảng viên');
-    const preview = escapeHtml(c.lastMessage || '');
-    return `<button type="button" class="student-chat-conv-btn${active}" data-staff-id="${sid}">
+    const preview = escapeHtml(c.lastMessage || '—');
+    return `<button type="button" class="student-chat-conv-row${active}" data-staff-id="${sid}">
       <span class="student-chat-conv-name">${name}${unread > 0 ? `<em class="student-chat-conv-unread">${unread}</em>` : ''}</span>
       <span class="student-chat-conv-preview">${preview}</span>
     </button>`;
   }).join('');
-  list.querySelectorAll('.student-chat-conv-btn').forEach((btn) => {
-    btn.addEventListener('click', () => {
-      const sid = Number(btn.getAttribute('data-staff-id'));
-      pickStaffChat(sid);
-    });
+  list.querySelectorAll('.student-chat-conv-row').forEach((btn) => {
+    btn.addEventListener('click', () => selectStaffChat(Number(btn.getAttribute('data-staff-id'))));
   });
 }
 
-async function pickStaffChat(staffId) {
-  activeStaffId = staffId;
-  const head = document.getElementById('student-chat-thread-head');
-  const conv = chatConversations.find((c) => Number(c.staffId) === staffId);
-  if (head) head.textContent = conv?.staffName || conv?.staffEmail || 'Giảng viên';
-  const input = document.getElementById('student-chat-input');
-  const sendBtn = document.getElementById('student-chat-send');
-  if (input) input.disabled = !staffId;
-  if (sendBtn) sendBtn.disabled = !staffId;
-  renderChatConversations();
-  if (staffId) await loadChatMessages(staffId);
-}
-
-async function loadChatMessages(staffId) {
+async function loadChatMessages(staffId, silent = false) {
   const msgs = await window.go.main.App.GetChatMessages(staffId);
   chatMessages = Array.isArray(msgs) ? msgs : [];
-  renderChatMessages();
+  renderChatMessages(silent);
   updateChatBadge();
-  loadChatConversations().catch(console.error);
+  if (!silent) loadChatConversations().catch(console.error);
 }
 
-function renderChatMessages() {
+function renderChatMessages(silent = false) {
   const box = document.getElementById('student-chat-messages');
   if (!box) return;
+  const wasAtBottom = box.scrollHeight - box.scrollTop - box.clientHeight < 48;
   if (!chatMessages.length) {
     box.innerHTML = '<div class="student-chat-empty">Chưa có tin nhắn</div>';
+    lastRenderedMsgCount = 0;
     return;
   }
+  if (chatMessages.length === lastRenderedMsgCount && silent) return;
+  lastRenderedMsgCount = chatMessages.length;
   box.innerHTML = chatMessages.map((m) => {
     const role = m.senderRole === 'student' ? 'student' : 'staff';
     const time = m.createdAt ? new Date(m.createdAt).toLocaleTimeString('vi-VN', { hour: '2-digit', minute: '2-digit' }) : '';
-    const label = role === 'staff' ? (m.staffName || 'Giảng viên') : 'Bạn';
-    return `<div class="student-chat-bubble student-chat-bubble--${role}"><div class="student-chat-label">${label}</div><div class="student-chat-body">${escapeHtml(m.body || '')}</div><div class="student-chat-time">${time}</div></div>`;
+    return `<div class="student-chat-bubble student-chat-bubble--${role}">
+      <div class="student-chat-body">${escapeHtml(m.body || '')}</div>
+      <div class="student-chat-time">${time}</div>
+    </div>`;
   }).join('');
-  box.scrollTop = box.scrollHeight;
+  if (!silent || wasAtBottom) {
+    requestAnimationFrame(() => { box.scrollTop = box.scrollHeight; });
+  }
 }
 
 function escapeHtml(s) {
diff --git a/client/frontend/wailsjs/go/main/App.d.ts b/client/frontend/wailsjs/go/main/App.d.ts
index da304b0..59d3f96 100644
--- a/client/frontend/wailsjs/go/main/App.d.ts
+++ b/client/frontend/wailsjs/go/main/App.d.ts
@@ -22,3 +22,5 @@ export function NavigateToLogin():Promise<void>;
 export function SendChatMessage(arg1:string):Promise<void>;
 
 export function SendWebcamFrame(arg1:string):Promise<void>;
+
+export function UnlockChatAudio():Promise<void>;
diff --git a/client/frontend/wailsjs/go/main/App.js b/client/frontend/wailsjs/go/main/App.js
index a576798..9febf7c 100644
--- a/client/frontend/wailsjs/go/main/App.js
+++ b/client/frontend/wailsjs/go/main/App.js
@@ -45,3 +45,7 @@ export function SendChatMessage(arg1) {
 export function SendWebcamFrame(arg1) {
   return window['go']['main']['App']['SendWebcamFrame'](arg1);
 }
+
+export function UnlockChatAudio() {
+  return window['go']['main']['App']['UnlockChatAudio']();
+}
diff --git a/client/internal/winapi/window_windows.go b/client/internal/winapi/window_windows.go
new file mode 100644
index 0000000..7afca2e
--- /dev/null
+++ b/client/internal/winapi/window_windows.go
@@ -0,0 +1,91 @@
+//go:build windows
+
+package winapi
+
+import (
+	"strings"
+	"syscall"
+	"time"
+	"unsafe"
+)
+
+var (
+	user32Window              = syscall.NewLazyDLL("user32.dll")
+	procFindWindowW           = user32Window.NewProc("FindWindowW")
+	procEnumWindows           = user32Window.NewProc("EnumWindows")
+	procGetWindowTextW        = user32Window.NewProc("GetWindowTextW")
+	procIsWindowVisible       = user32Window.NewProc("IsWindowVisible")
+	procShowWindow            = user32Window.NewProc("ShowWindow")
+	procSetForegroundWindow   = user32Window.NewProc("SetForegroundWindow")
+	procFlashWindowEx         = user32Window.NewProc("FlashWindowEx")
+	procMessageBeep           = user32Window.NewProc("MessageBeep")
+)
+
+const (
+	swRestore = 9
+)
+
+type flashwinfo struct {
+	cbSize    uint32
+	hwnd      uintptr
+	dwFlags   uint32
+	uCount    uint32
+	dwTimeout uint32
+}
+
+// ActivateAppWindow — đưa cửa sổ app lên trước + nhấp nháy taskbar
+func ActivateAppWindow(titleHint string) {
+	hwnd := findWindowByTitleContains(titleHint)
+	if hwnd == 0 {
+		return
+	}
+	_, _, _ = procShowWindow.Call(hwnd, swRestore)
+	_, _, _ = procSetForegroundWindow.Call(hwnd)
+	var fi flashwinfo
+	fi.cbSize = uint32(unsafe.Sizeof(fi))
+	fi.hwnd = hwnd
+	fi.dwFlags = 0x0000000E // FLASHW_ALL | FLASHW_TIMERNOFG
+	fi.uCount = 4
+	fi.dwTimeout = 0
+	_, _, _ = procFlashWindowEx.Call(uintptr(unsafe.Pointer(&fi)))
+}
+
+// PlayNotifySound — beep hệ thống Windows (không phụ thuộc autoplay trình duyệt)
+func PlayNotifySound() {
+	_, _, _ = procMessageBeep.Call(0x00000040) // MB_ICONASTERISK
+	time.Sleep(120 * time.Millisecond)
+	_, _, _ = procMessageBeep.Call(0xFFFFFFFF) // MB_OK
+}
+
+var enumTargetTitle string
+var enumFoundHwnd uintptr
+
+var enumWindowsCallback = syscall.NewCallback(func(hwnd uintptr, lParam uintptr) uintptr {
+	ret, _, _ := procIsWindowVisible.Call(hwnd)
+	if ret == 0 {
+		return 1
+	}
+	buf := make([]uint16, 256)
+	_, _, _ = procGetWindowTextW.Call(hwnd, uintptr(unsafe.Pointer(&buf[0])), 256)
+	title := syscall.UTF16ToString(buf)
+	if title != "" && strings.Contains(strings.ToLower(title), strings.ToLower(enumTargetTitle)) {
+		enumFoundHwnd = hwnd
+		return 0
+	}
+	return 1
+})
+
+func findWindowByTitleContains(hint string) uintptr {
+	if hint == "" {
+		return 0
+	}
+	titlePtr, _ := syscall.UTF16PtrFromString(hint)
+	hwnd, _, _ := procFindWindowW.Call(0, uintptr(unsafe.Pointer(titlePtr)))
+	if hwnd != 0 {
+		return hwnd
+	}
+	enumTargetTitle = hint
+	enumFoundHwnd = 0
+	_, _, _ = procEnumWindows.Call(enumWindowsCallback, 0)
+	return enumFoundHwnd
+}