diff --git a/apps/web/src/components/chat/Chat.tsx b/apps/web/src/components/chat/Chat.tsx
index 8462989..4168c42 100644
--- a/apps/web/src/components/chat/Chat.tsx
+++ b/apps/web/src/components/chat/Chat.tsx
@@ -342,6 +342,31 @@ export const Chat = forwardRef<ChatRef, ChatProps>(function Chat(
       )}
 
       {/* Input Area */}
+      {!user && (
+        <div className="mx-4 mb-2 lg:mx-auto lg:max-w-4xl lg:px-8">
+          <div
+            className="flex items-center justify-center gap-2 rounded-lg border px-4 py-3 text-center"
+            style={{
+              backgroundColor: "rgb(var(--surface-1))",
+              borderColor: "rgb(var(--border-default))",
+            }}
+          >
+            <svg
+              className="h-4 w-4"
+              style={{ color: "rgb(var(--text-secondary))" }}
+              fill="none"
+              viewBox="0 0 24 24"
+              stroke="currentColor"
+              strokeWidth={2}
+            >
+              <path d="M15 7a2 2 0 012 2m4 0a6 6 0 01-7.743 5.743L11 17H9v2H7v2H4a1 1 0 01-1-1v-2.586a1 1 0 01.293-.707l5.964-5.964A6 6 0 1121 9z" />
+            </svg>
+            <span className="text-sm" style={{ color: "rgb(var(--text-secondary))" }}>
+              Sign in to chat with Jarvis
+            </span>
+          </div>
+        </div>
+      )}
       <div
         className="sticky bottom-0 border-t"
         style={{
@@ -352,7 +377,7 @@ export const Chat = forwardRef<ChatRef, ChatProps>(function Chat(
         <div className="mx-auto max-w-4xl px-4 py-4 lg:px-8">
           <ChatInput
             onSend={handleSendMessage}
-            disabled={isChatLoading}
+            disabled={isChatLoading || !user}
             inputRef={inputRef}
             isStreaming={isStreaming}
             onStopStreaming={abortStream}
diff --git a/apps/web/src/components/chat/ChatOverlay.tsx b/apps/web/src/components/chat/ChatOverlay.tsx
index cd7cdaa..9a920da 100644
--- a/apps/web/src/components/chat/ChatOverlay.tsx
+++ b/apps/web/src/components/chat/ChatOverlay.tsx
@@ -55,8 +55,8 @@ export function ChatOverlay(): React.JSX.Element {
         onClick={open}
         className="fixed bottom-6 right-6 z-50 flex h-14 w-14 items-center justify-center rounded-full shadow-lg transition-all hover:scale-110 focus:outline-none focus:ring-2 focus:ring-offset-2 lg:bottom-8 lg:right-8"
         style={{
-          backgroundColor: "rgb(var(--accent-primary))",
-          color: "rgb(var(--text-on-accent))",
+          backgroundColor: "var(--accent-primary, #10b981)",
+          color: "var(--text-on-accent, #ffffff)",
         }}
         aria-label="Open chat"
         title="Open Jarvis chat (Cmd+Shift+J)"
@@ -78,18 +78,18 @@ export function ChatOverlay(): React.JSX.Element {
   if (isMinimized) {
     return (
       <div
-        className="fixed bottom-0 right-0 z-40 w-full sm:w-96"
+        className="fixed bottom-0 right-0 z-40 w-full shadow-2xl sm:w-96"
         style={{
-          backgroundColor: "rgb(var(--surface-0))",
-          borderColor: "rgb(var(--border-default))",
+          backgroundColor: "var(--surface-0, #ffffff)",
+          borderColor: "var(--border-default, #e5e7eb)",
         }}
       >
         <button
           onClick={expand}
           className="flex w-full items-center justify-between border-t px-4 py-3 text-left transition-colors hover:bg-black/5 focus:outline-none focus:ring-2 focus:ring-inset"
           style={{
-            borderColor: "rgb(var(--border-default))",
-            backgroundColor: "rgb(var(--surface-0))",
+            borderColor: "var(--border-default, #e5e7eb)",
+            backgroundColor: "var(--surface-0, #ffffff)",
           }}
           aria-label="Expand chat"
         >
@@ -135,10 +135,10 @@ export function ChatOverlay(): React.JSX.Element {
 
       {/* Chat Panel */}
       <div
-        className="fixed inset-y-0 right-0 z-40 flex w-full flex-col border-l sm:w-96 lg:inset-y-16"
+        className="fixed inset-y-0 right-0 z-40 flex w-full flex-col border-l shadow-2xl sm:w-96 lg:inset-y-16"
         style={{
-          backgroundColor: "rgb(var(--surface-0))",
-          borderColor: "rgb(var(--border-default))",
+          backgroundColor: "var(--surface-0, #ffffff)",
+          borderColor: "var(--border-default, #e5e7eb)",
         }}
       >
         {/* Header */}
diff --git a/apps/web/src/hooks/useChat.ts b/apps/web/src/hooks/useChat.ts
index b98ab03..4d25250 100644
--- a/apps/web/src/hooks/useChat.ts
+++ b/apps/web/src/hooks/useChat.ts
@@ -4,12 +4,7 @@
  */
 
 import { useState, useCallback, useRef } from "react";
-import {
-  sendChatMessage,
-  streamChatMessage,
-  streamGuestChat,
-  type ChatMessage as ApiChatMessage,
-} from "@/lib/api/chat";
+import { streamChatMessage, type ChatMessage as ApiChatMessage } from "@/lib/api/chat";
 import { createConversation, updateConversation, getIdea, type Idea } from "@/lib/api/ideas";
 import { safeJsonParse, isMessageArray } from "@/lib/utils/safe-json";
 
@@ -219,8 +214,6 @@ export function useChat(options: UseChatOptions = {}): UseChatReturn {
       const controller = new AbortController();
       abortControllerRef.current = controller;
 
-      let streamingSucceeded = false;
-
       try {
         await new Promise<void>((resolve, reject) => {
           let hasReceivedData = false;
@@ -248,7 +241,6 @@ export function useChat(options: UseChatOptions = {}): UseChatReturn {
               });
             },
             () => {
-              streamingSucceeded = true;
               setIsStreaming(false);
               abortControllerRef.current = null;
               resolve();
@@ -279,140 +271,26 @@ export function useChat(options: UseChatOptions = {}): UseChatReturn {
           return;
         }
 
-        // Streaming failed - check if auth error, try guest mode
-        const isAuthError =
-          err instanceof Error &&
-          (err.message.includes("403") ||
-            err.message.includes("401") ||
-            err.message.includes("auth") ||
-            err.message.includes("Forbidden"));
+        // Streaming failed — show error (no guest fallback, auth required)
+        console.warn("Streaming failed", {
+          error: err instanceof Error ? err : new Error(String(err)),
+        });
 
-        if (isAuthError) {
-          console.warn("Auth failed, trying guest chat mode");
+        setMessages((prev) => {
+          const withoutPlaceholder = prev.filter((m) => m.id !== assistantMessageId);
+          messagesRef.current = withoutPlaceholder;
+          return withoutPlaceholder;
+        });
+        setIsStreaming(false);
+        setIsLoading(false);
 
-          // Try guest chat streaming
-          try {
-            await new Promise<void>((guestResolve, guestReject) => {
-              let hasReceivedData = false;
-
-              streamGuestChat(
-                request,
-                (chunk: string) => {
-                  if (!hasReceivedData) {
-                    hasReceivedData = true;
-                    setIsLoading(false);
-                    setIsStreaming(true);
-                    setMessages((prev) => {
-                      const updated = [...prev, { ...placeholderMessage }];
-                      messagesRef.current = updated;
-                      return updated;
-                    });
-                  }
-
-                  setMessages((prev) => {
-                    const updated = prev.map((msg) =>
-                      msg.id === assistantMessageId ? { ...msg, content: msg.content + chunk } : msg
-                    );
-                    messagesRef.current = updated;
-                    return updated;
-                  });
-                },
-                () => {
-                  streamingSucceeded = true;
-                  setIsStreaming(false);
-                  guestResolve();
-                },
-                (guestErr: Error) => {
-                  guestReject(guestErr);
-                },
-                controller.signal
-              );
-            });
-          } catch (guestErr: unknown) {
-            // Guest also failed
-            setMessages((prev) => {
-              const withoutPlaceholder = prev.filter((m) => m.id !== assistantMessageId);
-              messagesRef.current = withoutPlaceholder;
-              return withoutPlaceholder;
-            });
-            const errorMsg = guestErr instanceof Error ? guestErr.message : "Chat unavailable";
-            setError(`Unable to connect to chat: ${errorMsg}`);
-            setIsLoading(false);
-            return;
-          }
-        } else {
-          // Streaming failed — fall back to non-streaming
-          console.warn("Streaming failed, falling back to non-streaming", {
-            error: err instanceof Error ? err : new Error(String(err)),
-          });
-
-          setMessages((prev) => {
-            const withoutPlaceholder = prev.filter((m) => m.id !== assistantMessageId);
-            messagesRef.current = withoutPlaceholder;
-            return withoutPlaceholder;
-          });
-          setIsStreaming(false);
-
-          try {
-            const response = await sendChatMessage(request);
-
-            const assistantMessage: Message = {
-              id: `assistant-${Date.now().toString()}`,
-              role: "assistant",
-              content: response.message.content,
-              createdAt: new Date().toISOString(),
-              model: response.model,
-              promptTokens: response.promptEvalCount ?? 0,
-              completionTokens: response.evalCount ?? 0,
-              totalTokens: (response.promptEvalCount ?? 0) + (response.evalCount ?? 0),
-            };
-
-            setMessages((prev) => {
-              const updated = [...prev, assistantMessage];
-              messagesRef.current = updated;
-              return updated;
-            });
-
-            streamingSucceeded = true;
-          } catch (fallbackErr: unknown) {
-            const errorMsg =
-              fallbackErr instanceof Error ? fallbackErr.message : "Failed to send message";
-            setError("Unable to send message. Please try again.");
-            onError?.(fallbackErr instanceof Error ? fallbackErr : new Error(errorMsg));
-            console.error("Failed to send chat message", {
-              error: fallbackErr,
-              errorType: "LLM_ERROR",
-              conversationId: conversationIdRef.current,
-              messageLength: content.length,
-              messagePreview: content.substring(0, 50),
-              model,
-              messageCount: messagesRef.current.length,
-              timestamp: new Date().toISOString(),
-            });
-
-            const errorMessage: Message = {
-              id: `error-${String(Date.now())}`,
-              role: "assistant",
-              content: "Something went wrong. Please try again.",
-              createdAt: new Date().toISOString(),
-            };
-            setMessages((prev) => {
-              const updated = [...prev, errorMessage];
-              messagesRef.current = updated;
-              return updated;
-            });
-            setIsLoading(false);
-            return;
-          }
-        }
+        const errorMsg = err instanceof Error ? err.message : "Chat unavailable";
+        setError(`Chat error: ${errorMsg}`);
+        return;
       }
 
       setIsLoading(false);
 
-      if (!streamingSucceeded) {
-        return;
-      }
-
       const finalMessages = messagesRef.current;
 
       const isFirstMessage =