diff --git a/frontend/src/components/meeting/MeetingToolbar.vue b/frontend/src/components/meeting/MeetingToolbar.vue
index 9337b97..03a6fe0 100644
--- a/frontend/src/components/meeting/MeetingToolbar.vue
+++ b/frontend/src/components/meeting/MeetingToolbar.vue
@@ -123,6 +123,11 @@ const emitIf = (name) => {
   background: rgba(17, 24, 39, 0.88);
   backdrop-filter: blur(16px);
   border-top: 1rpx solid rgba(255, 255, 255, 0.08);
+  /* flex-shrink:0 保证 body 内容高度过大时不会把 toolbar 挤出视口；
+     position:relative + z-index 提升按钮点击层级，避免 ChatPanel 遮挡 */
+  flex-shrink: 0;
+  position: relative;
+  z-index: 15;
 }
 
 .btn {
diff --git a/frontend/src/pages/meeting/preview.vue b/frontend/src/pages/meeting/preview.vue
index a0dfd0d..f1b953e 100644
--- a/frontend/src/pages/meeting/preview.vue
+++ b/frontend/src/pages/meeting/preview.vue
@@ -197,8 +197,8 @@ const startPreview = async () => {
     const constraints = {
       audio: selectedAudioId.value ? { deviceId: { exact: selectedAudioId.value } } : true,
       video: selectedVideoId.value
-        ? { deviceId: { exact: selectedVideoId.value }, width: 640, height: 480 }
-        : { width: 640, height: 480 }
+        ? { deviceId: { exact: selectedVideoId.value }, width: { ideal: 1280 }, height: { ideal: 720 }, frameRate: { ideal: 24, max: 30 } }
+        : { width: { ideal: 1280 }, height: { ideal: 720 }, frameRate: { ideal: 24, max: 30 } }
     }
     previewStream = await navigator.mediaDevices.getUserMedia(constraints)
     hasPermission.value = true
diff --git a/frontend/src/pages/meeting/room.vue b/frontend/src/pages/meeting/room.vue
index b93e42f..bd5cf7d 100644
--- a/frontend/src/pages/meeting/room.vue
+++ b/frontend/src/pages/meeting/room.vue
@@ -379,6 +379,11 @@ const onCamToggle = async () => {
 const openInvite = () => { inviteVisible.value = true }
 const openMembers = () => { memberVisible.value = true }
 const openChat = () => {
+  // 点击工具栏聊天按钮时进行切换：已打开 → 关闭；未打开 → 打开并标记已读
+  if (chatVisible.value) {
+    chatVisible.value = false
+    return
+  }
   chatVisible.value = true
   meetingStore.markChatsRead()
 }
@@ -555,6 +560,7 @@ onUnload(() => {
   background: linear-gradient(to bottom, rgba(0, 0, 0, 0.55), rgba(0, 0, 0, 0));
   position: relative;
   z-index: 5;
+  flex-shrink: 0;
 }
 
 .top-left {
diff --git a/frontend/src/store/meeting.js b/frontend/src/store/meeting.js
index 8399baf..00ec01f 100644
--- a/frontend/src/store/meeting.js
+++ b/frontend/src/store/meeting.js
@@ -648,9 +648,11 @@ export const useMeetingStore = defineStore('meeting', () => {
   const startLocalVideo = async (deviceId) => {
     if (!_engine) throw new Error('未连接')
     if (localProducers.video) return
+    // 与预览页保持一致的 HD 分辨率（ideal 1280x720，允许浏览器在设备不支持时降级）
     const videoConstraints = {
-      width: 640,
-      height: 480,
+      width: { ideal: 1280 },
+      height: { ideal: 720 },
+      frameRate: { ideal: 24, max: 30 },
       ...(deviceId ? { deviceId: { exact: deviceId } } : {})
     }
     const stream = await navigator.mediaDevices.getUserMedia({ video: videoConstraints })