frontend/src/App.css

@@ -265,6 +265,11 @@ body {
   margin-bottom: 4px;
 }
 
+.video-placeholder__hint {
+  font-size: 0.72rem;
+  opacity: 0.6;
+}
+
 .video-indicator {
   position: absolute;
   bottom: 16px;
@@ -488,6 +493,32 @@ body {
   gap: 12px;
 }
 
+.chat-panel__welcome {
+  display: flex;
+  flex-direction: column;
+  align-items: center;
+  justify-content: center;
+  flex: 1;
+  gap: 12px;
+  color: var(--color-text-muted);
+  font-size: 0.85rem;
+  padding: 40px 0;
+}
+
+.chat-panel__welcome-icon {
+  font-size: 2.4rem;
+  opacity: 0.12;
+  margin-bottom: 4px;
+}
+
+.chat-panel__welcome-hint {
+  font-size: 0.75rem;
+  opacity: 0.6;
+  max-width: 240px;
+  text-align: center;
+  line-height: 1.5;
+}
+
 .chat-panel--empty {
   display: flex;
   flex-direction: column;

frontend/src/App.tsx

@@ -173,6 +173,16 @@ function App() {
                 <span>点击下方按钮开始对话</span>
               </div>
             )}
+            {isConnected && !isCameraOn && (
+              <div className="video-placeholder">
+                <svg className="video-placeholder__icon" width="48" height="48" viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="1.2" strokeLinecap="round" strokeLinejoin="round">
+                  <path d="M23 19a2 2 0 0 1-2 2H3a2 2 0 0 1-2-2V8a2 2 0 0 1 2-2h4l2-3h6l2 3h4a2 2 0 0 1 2 2z" />
+                  <circle cx="12" cy="13" r="4" />
+                </svg>
+                <span>摄像头未开启</span>
+                <span className="video-placeholder__hint">可在右侧聊天框打字对话</span>
+              </div>
+            )}
           </div>
 
           {/* 视频下方控制栏 */}

frontend/src/components/ChatPanel/index.tsx

@@ -51,22 +51,13 @@ export function ChatPanel({ messages, currentReply, connectionStatus, onSendText
     setInputText("");
   };
 
-  // 空状态
-  if (messages.length === 0 && !currentReply) {
-    if (!isConnected) {
-      return (
-        <div className="chat-panel chat-panel--empty">
-          <span className="chat-panel--empty-icon">💬</span>
-          <p>点击下方按钮开始对话</p>
-          <span className="chat-panel--empty-hint">连接后可通过摄像头和麦克风与 AI 交互</span>
-        </div>
-      );
-    }
+  // 未连接时的空状态
+  if (!isConnected) {
     return (
       <div className="chat-panel chat-panel--empty">
-        <span className="chat-panel--empty-icon">🎙️</span>
-        <p>对着摄像头说话即可</p>
-        <span className="chat-panel--empty-hint">AI 会自动识别你的语音并分析画面</span>
+        <span className="chat-panel--empty-icon">💬</span>
+        <p>点击下方按钮开始对话</p>
+        <span className="chat-panel--empty-hint">连接后可打字或语音与 AI 交互</span>
       </div>
     );
   }
@@ -74,6 +65,15 @@ export function ChatPanel({ messages, currentReply, connectionStatus, onSendText
   return (
     <div className="chat-panel">
       <div className="chat-panel__messages" ref={containerRef}>
+        {/* 空状态提示 */}
+        {messages.length === 0 && !currentReply && (
+          <div className="chat-panel__welcome">
+            <span className="chat-panel__welcome-icon">💬</span>
+            <p>在下方输入文字开始对话</p>
+            <span className="chat-panel__welcome-hint">也可以开启麦克风用语音对话</span>
+          </div>
+        )}
+
         {messages.map((msg, index) => (
           <div key={index} className={`chat-message chat-message--${msg.role}`}>
             <div className="chat-message__role">
@@ -104,8 +104,8 @@ export function ChatPanel({ messages, currentReply, connectionStatus, onSendText
         <div ref={bottomRef} />
       </div>
 
-      {/* 文本输入框 */}
-      {isConnected && onSendText && (
+      {/* 文本输入框 - 连接后始终显示 */}
+      {onSendText && (
         <form className="chat-input" onSubmit={handleSubmit}>
           <input
             type="text"

frontend/src/hooks/useVisionSession.ts

@@ -284,21 +284,26 @@ export function useVisionSession() {
 
   /** 启动会话 */
   const startSession = useCallback(async () => {
-    // 1. 获取摄像头和麦克风
-    await startCamera();
-    setIsCameraOn(true);
-    const micStream = await startMic();
-    if (!micStream) {
-      showToast("无法获取麦克风权限", "error");
-      return;
-    }
-    setIsMicOn(true);
-
-    // 2. 连接 WebSocket
+    // 1. 连接 WebSocket（必须）
     connect();
 
-    // 3. 启动 VAD（传入麦克风 stream）
-    await startVAD(micStream);
+    // 2. 尝试获取摄像头（可选）
+    try {
+      await startCamera();
+      setIsCameraOn(true);
+    } catch {
+      console.warn("[Session] 无法获取摄像头权限，将以纯文本模式运行");
+    }
+
+    // 3. 尝试获取麦克风（可选）
+    const micStream = await startMic();
+    if (micStream) {
+      setIsMicOn(true);
+      // 4. 启动 VAD（仅在麦克风可用时）
+      await startVAD(micStream);
+    } else {
+      console.warn("[Session] 无法获取麦克风权限，将以文本输入模式运行");
+    }
   }, [startCamera, startMic, connect, startVAD]);
 
   /** 结束会话 */