diff --git a/src/components/chat/GlobalChatbox.tsx b/src/components/chat/GlobalChatbox.tsx
index 0ac1d9d..35aebc0 100644
--- a/src/components/chat/GlobalChatbox.tsx
+++ b/src/components/chat/GlobalChatbox.tsx
@@ -25,6 +25,7 @@ import SendRounded from "@mui/icons-material/SendRounded";
 import StopRounded from "@mui/icons-material/StopRounded";
 import AutoAwesome from "@mui/icons-material/AutoAwesome"; // Sparkle icon for AI
 import PersonRounded from "@mui/icons-material/PersonRounded";
+import ErrorOutlineRounded from "@mui/icons-material/ErrorOutlineRounded";
 
 // Logic
 import { streamCopilotChat } from "@/lib/chatStream";
@@ -34,6 +35,7 @@ type Message = {
   id: string;
   role: "user" | "assistant";
   content: string;
+  isError?: boolean;
 };
 
 type Props = {
@@ -43,6 +45,12 @@ type Props = {
 
 // Utils
 const createId = () => `${Date.now()}-${Math.random().toString(36).slice(2, 8)}`;
+const CHAT_STORAGE_KEY = "tjwater_copilot_chat_state_v1";
+
+type PersistedChatState = {
+  messages: Message[];
+  conversationId?: string;
+};
 
 // --- Components ---
 
@@ -114,6 +122,7 @@ export const GlobalChatbox: React.FC<Props> = ({ open, onClose }) => {
   const abortRef = useRef<AbortController | null>(null);
   const bottomRef = useRef<HTMLDivElement>(null);
   const inputRef = useRef<HTMLInputElement | null>(null);
+  const hasHydratedRef = useRef(false);
   const theme = useTheme();
 
   const canSend = useMemo(() => input.trim().length > 0 && !isStreaming, [input, isStreaming]);
@@ -131,6 +140,40 @@ export const GlobalChatbox: React.FC<Props> = ({ open, onClose }) => {
     return () => window.clearTimeout(timer);
   }, [open]);
 
+  useEffect(() => {
+    try {
+      const storedRaw = window.localStorage.getItem(CHAT_STORAGE_KEY);
+      if (!storedRaw) {
+        hasHydratedRef.current = true;
+        return;
+      }
+      const parsed = JSON.parse(storedRaw) as PersistedChatState;
+      if (!Array.isArray(parsed.messages)) {
+        console.error("[GlobalChatbox] Invalid persisted messages format.");
+        window.localStorage.removeItem(CHAT_STORAGE_KEY);
+        hasHydratedRef.current = true;
+        return;
+      }
+      setMessages(parsed.messages);
+      setConversationId(parsed.conversationId);
+    } catch (error) {
+      console.error("[GlobalChatbox] Failed to read persisted chat state:", error);
+      window.localStorage.removeItem(CHAT_STORAGE_KEY);
+    } finally {
+      hasHydratedRef.current = true;
+    }
+  }, []);
+
+  useEffect(() => {
+    if (!hasHydratedRef.current) return;
+    const state: PersistedChatState = { messages, conversationId };
+    try {
+      window.localStorage.setItem(CHAT_STORAGE_KEY, JSON.stringify(state));
+    } catch (error) {
+      console.error("[GlobalChatbox] Failed to persist chat state:", error);
+    }
+  }, [messages, conversationId]);
+
   const handleSend = async () => {
     const prompt = input.trim();
     if (!prompt || isStreaming) return;
@@ -159,7 +202,9 @@ export const GlobalChatbox: React.FC<Props> = ({ open, onClose }) => {
             if (!conversationId && event.conversationId) setConversationId(event.conversationId);
             setMessages((prev) =>
               prev.map((m) =>
-                m.id === assistantId ? { ...m, content: m.content + event.content } : m
+                m.id === assistantId
+                  ? { ...m, content: m.content + event.content, isError: false }
+                  : m
               )
             );
           } else if (event.type === "done") {
@@ -169,7 +214,11 @@ export const GlobalChatbox: React.FC<Props> = ({ open, onClose }) => {
             setMessages((prev) =>
               prev.map((m) =>
                 m.id === assistantId
-                  ? { ...m, content: m.content || `错误：${event.message}` }
+                  ? {
+                      ...m,
+                      content: m.content || `⚠️ **错误：** ${event.message}`,
+                      isError: true,
+                    }
                   : m
               )
             );
@@ -180,7 +229,11 @@ export const GlobalChatbox: React.FC<Props> = ({ open, onClose }) => {
     } catch (error) {
       if (abortRef.current?.signal.aborted) return;
       setMessages((prev) =>
-        prev.map((m) => (m.id === assistantId ? { ...m, content: `错误：${String(error)}` } : m))
+        prev.map((m) =>
+          m.id === assistantId
+            ? { ...m, content: `⚠️ **错误：** ${String(error)}`, isError: true }
+            : m
+        )
       );
       setIsStreaming(false);
     } finally {
@@ -330,6 +383,7 @@ export const GlobalChatbox: React.FC<Props> = ({ open, onClose }) => {
 
             {messages.map((message) => {
                 const isUser = message.role === "user";
+                const isErrorMessage = Boolean(message.isError);
                 return (
                 <motion.div
                     key={message.id}
@@ -347,54 +401,130 @@ export const GlobalChatbox: React.FC<Props> = ({ open, onClose }) => {
                     }}
                 >
                     {!isUser && (
-                         <Avatar sx={{ width: 28, height: 28, bgcolor: alpha(theme.palette.secondary.main, 0.1), mb: 0.5 }}>
-                            <AutoAwesome sx={{ fontSize: 16, color: "secondary.main" }} />
+                         <Avatar sx={{ width: 28, height: 28, bgcolor: isErrorMessage ? alpha(theme.palette.error.main, 0.12) : alpha(theme.palette.secondary.main, 0.1), mb: 0.5 }}>
+                            {isErrorMessage ? (
+                              <ErrorOutlineRounded sx={{ fontSize: 16, color: "error.main" }} />
+                            ) : (
+                              <AutoAwesome sx={{ fontSize: 16, color: "secondary.main" }} />
+                            )}
                         </Avatar>
                     )}
 
                     <Paper
-                        elevation={isUser ? 8 : 2}
+                        elevation={isUser ? 8 : isErrorMessage ? 1 : 2}
                         sx={{
                             p: 2.5,
                             borderRadius: 4,
                             borderBottomRightRadius: isUser ? 4 : 24,
                             borderBottomLeftRadius: !isUser ? 4 : 24,
-                            bgcolor: isUser ? "primary.main" : "#fff",
-                            color: isUser ? "#fff" : "text.primary",
-                            background: isUser ? `linear-gradient(135deg, ${theme.palette.primary.main}, ${theme.palette.primary.dark})` : undefined,
+                            bgcolor: isUser ? "primary.main" : isErrorMessage ? alpha(theme.palette.error.light, 0.18) : "#fff",
+                            color: isUser ? "#fff" : isErrorMessage ? "error.dark" : "text.primary",
+                            background: isUser
+                                ? `linear-gradient(135deg, ${theme.palette.primary.main}, ${theme.palette.primary.dark})`
+                                : isErrorMessage
+                                  ? `linear-gradient(135deg, ${alpha(theme.palette.error.light, 0.28)}, ${alpha(theme.palette.error.main, 0.12)})`
+                                  : undefined,
+                            border: isErrorMessage ? `1px solid ${alpha(theme.palette.error.main, 0.35)}` : "none",
                             boxShadow: isUser 
                                 ? `0 8px 24px -4px ${alpha(theme.palette.primary.main, 0.5)}` 
+                                : isErrorMessage
+                                  ? `0 4px 16px -4px ${alpha(theme.palette.error.main, 0.2)}`
                                 : `0 4px 16px -4px ${alpha("#000", 0.05)}`,
                             
                             // Markdown Styles
-                            "& p": { m: 0, lineHeight: 1.6 },
+                            "& p": {
+                                m: 0,
+                                lineHeight: 1.75,
+                                whiteSpace: "pre-wrap",
+                                color: isUser ? alpha("#fff", 0.96) : isErrorMessage ? theme.palette.error.dark : theme.palette.text.primary,
+                            },
+                            "& h1, & h2, & h3, & h4, & h5, & h6": {
+                                mt: 0.6,
+                                mb: 0.6,
+                                lineHeight: 1.35,
+                                fontWeight: 700,
+                                color: isUser ? "#fff" : isErrorMessage ? theme.palette.error.dark : theme.palette.text.primary,
+                            },
+                            "& h1": { fontSize: "1.2rem" },
+                            "& h2": { fontSize: "1.12rem" },
+                            "& h3": { fontSize: "1.04rem" },
+                            "& a": {
+                                color: isUser ? "#E3F2FD" : isErrorMessage ? theme.palette.error.main : theme.palette.primary.dark,
+                                textDecoration: "underline",
+                                wordBreak: "break-all",
+                                textUnderlineOffset: "2px",
+                                "&:hover": {
+                                  color: isUser ? "#fff" : isErrorMessage ? theme.palette.error.dark : theme.palette.primary.main,
+                                },
+                            },
                             "& code": {
                                 fontFamily: "monospace",
-                                bgcolor: isUser ? "rgba(255,255,255,0.2)" : alpha(theme.palette.grey[100], 0.8),
+                                bgcolor: isUser
+                                  ? "rgba(255,255,255,0.2)"
+                                  : isErrorMessage
+                                    ? alpha(theme.palette.error.main, 0.08)
+                                    : alpha(theme.palette.grey[100], 0.95),
+                                color: isUser ? "#fff" : isErrorMessage ? theme.palette.error.dark : alpha(theme.palette.text.primary, 0.95),
                                 px: 0.8,
                                 py: 0.2,
                                 borderRadius: 1,
                                 fontSize: "0.85em",
-                                border: isUser ? "none" : `1px solid ${alpha(theme.palette.divider, 0.1)}`,
+                                border: isUser
+                                  ? "none"
+                                  : isErrorMessage
+                                    ? `1px solid ${alpha(theme.palette.error.main, 0.25)}`
+                                    : `1px solid ${alpha(theme.palette.divider, 0.35)}`,
                             },
                             "& pre": {
-                                bgcolor: isUser ? "rgba(0,0,0,0.25)" : "#222",
-                                color: "#f8f8f2",
+                                bgcolor: isUser
+                                  ? "rgba(11, 18, 32, 0.56)"
+                                  : isErrorMessage
+                                    ? alpha(theme.palette.error.main, 0.08)
+                                    : "#0F172A",
+                                color: isUser
+                                  ? "#F8FAFC"
+                                  : isErrorMessage
+                                    ? theme.palette.error.dark
+                                    : "#E2E8F0",
                                 p: 2,
                                 borderRadius: 3,
                                 overflowX: "auto",
                                 my: 1.5,
-                                fontSize: "0.85em",
-                                border: "1px solid rgba(255,255,255,0.1)",
+                                fontSize: "0.88em",
+                                border: isErrorMessage
+                                  ? `1px solid ${alpha(theme.palette.error.main, 0.3)}`
+                                  : `1px solid ${isUser ? alpha("#fff", 0.12) : alpha("#94A3B8", 0.35)}`,
+                            },
+                            "& pre code": {
+                                bgcolor: "transparent",
+                                border: "none",
+                                px: 0,
+                                py: 0,
+                                color: "inherit",
                             },
                             "& ul, & ol": { pl: 2.5, my: 1 },
+                            "& li": {
+                                my: 0.35,
+                                lineHeight: 1.65,
+                            },
+                            "& blockquote": {
+                                m: 0,
+                                my: 1,
+                                pl: 1.5,
+                                borderLeft: `3px solid ${isErrorMessage ? alpha(theme.palette.error.main, 0.5) : alpha(theme.palette.divider, 0.5)}`,
+                                color: isUser ? alpha("#fff", 0.9) : isErrorMessage ? theme.palette.error.dark : "text.secondary",
+                                bgcolor: isUser
+                                  ? alpha("#fff", 0.08)
+                                  : isErrorMessage
+                                    ? alpha(theme.palette.error.main, 0.06)
+                                    : alpha(theme.palette.grey[100], 0.7),
+                                borderRadius: 1,
+                                py: 0.5,
+                                pr: 1,
+                            },
                         }}
                     >
-                        {isUser ? (
-                            <Typography variant="body2" fontSize="0.95rem" sx={{ whiteSpace: "pre-wrap" }}>{message.content}</Typography>
-                        ) : (
-                            <ReactMarkdown>{message.content || "..."}</ReactMarkdown>
-                        )}
+                        <ReactMarkdown>{message.content || "..."}</ReactMarkdown>
                     </Paper>
                 </motion.div>
                 );