feat: enhance Replay mode

web/src/app/_components/messages-block.tsx

@@ -1,7 +1,8 @@
 // Copyright (c) 2025 Bytedance Ltd. and/or its affiliates
 // SPDX-License-Identifier: MIT
 
-import { FastForward } from "lucide-react";
+import { motion } from "framer-motion";
+import { FastForward, Play } from "lucide-react";
 import { useCallback, useRef, useState } from "react";
 
 import { Button } from "~/components/ui/button";
@@ -21,11 +22,13 @@ import { ConversationStarter } from "./conversation-starter";
 import { InputBox } from "./input-box";
 import { MessageListView } from "./message-list-view";
 import { RainbowText } from "./rainbow-text";
+import { Welcome } from "./welcome";
 
 export function MessagesBlock({ className }: { className?: string }) {
   const messageCount = useStore((state) => state.messageIds.length);
   const responding = useStore((state) => state.responding);
   const { isReplay } = useReplay();
+  const [replayStarted, setReplayStarted] = useState(false);
   const abortControllerRef = useRef<AbortController | null>(null);
   const [feedback, setFeedback] = useState<{ option: Option } | null>(null);
   const handleSend = useCallback(
@@ -61,6 +64,10 @@ export function MessagesBlock({ className }: { className?: string }) {
   const handleRemoveFeedback = useCallback(() => {
     setFeedback(null);
   }, [setFeedback]);
+  const handleStartReplay = useCallback(() => {
+    setReplayStarted(true);
+    void sendMessage();
+  }, [setReplayStarted]);
   const [fastForwarding, setFastForwarding] = useState(false);
   const handleFastForwardReplay = useCallback(() => {
     setFastForwarding(!fastForwarding);
@@ -91,17 +98,42 @@ export function MessagesBlock({ className }: { className?: string }) {
           />
         </div>
       ) : (
-        <div className="flex h-42 w-full items-center justify-center">
+        <>
-          <Card className="w-full">
+          <div
+            className={cn(
+              "fixed bottom-[calc(50vh+80px)] left-0 transition-all duration-500 ease-out",
+              replayStarted && "pointer-events-none scale-150 opacity-0",
+            )}
+          >
+            <Welcome />
+          </div>
+          <motion.div
+            className="h-42 w-full items-center justify-center transition-all duration-300"
+            initial={{ opacity: 0, y: 200 }}
+            animate={{ opacity: 1, y: 0 }}
+            transition={{ duration: 0.3 }}
+          >
+            <Card
+              className={cn(
+                "w-full transition-all duration-300",
+                !replayStarted && "translate-y-[-40vh]",
+              )}
+            >
               <div className="flex items-center justify-between">
                 <div className="flex-grow">
                   <CardHeader>
                     <CardTitle>
-                    <RainbowText animated={responding}>Replay Mode</RainbowText>
+                      <RainbowText animated={responding}>
+                        Replay Mode
+                      </RainbowText>
                     </CardTitle>
                     <CardDescription>
                       <RainbowText animated={responding}>
-                      DeerFlow is now replaying the conversation...
+                        {responding
+                          ? "DeerFlow is now replaying the conversation..."
+                          : replayStarted
+                            ? "The replay has been stopped."
+                            : `You're now in DeerFlow's replay mode. Click the start button on the right to replay.`}
                       </RainbowText>
                     </CardDescription>
                   </CardHeader>
@@ -113,14 +145,21 @@ export function MessagesBlock({ className }: { className?: string }) {
                       variant={fastForwarding ? "default" : "outline"}
                       onClick={handleFastForwardReplay}
                     >
-                    Fast Forward
                       <FastForward size={16} />
+                      Fast Forward
+                    </Button>
+                  )}
+                  {!replayStarted && (
+                    <Button onClick={handleStartReplay}>
+                      <Play size={16} />
+                      Start
                     </Button>
                   )}
                 </div>
               </div>
             </Card>
-        </div>
+          </motion.div>
+        </>
       )}
     </div>
   );

web/src/app/app.tsx

@@ -0,0 +1,73 @@
+// Copyright (c) 2025 Bytedance Ltd. and/or its affiliates
+// SPDX-License-Identifier: MIT
+
+"use client";
+
+import { GithubOutlined } from "@ant-design/icons";
+import Link from "next/link";
+import { useMemo } from "react";
+
+import { Button } from "~/components/ui/button";
+import { useReplay } from "~/core/replay";
+import { useStore } from "~/core/store";
+import { cn } from "~/lib/utils";
+
+import { Logo } from "./_components/logo";
+import { MessagesBlock } from "./_components/messages-block";
+import { ResearchBlock } from "./_components/research-block";
+import { ThemeToggle } from "./_components/theme-toggle";
+import { Tooltip } from "./_components/tooltip";
+import { SettingsDialog } from "./_settings/dialogs/settings-dialog";
+
+export default function App() {
+  const { isReplay } = useReplay();
+  const openResearchId = useStore((state) => state.openResearchId);
+  const doubleColumnMode = useMemo(
+    () => openResearchId !== null,
+    [openResearchId],
+  );
+  return (
+    <div className="flex h-full w-full justify-center">
+      <header className="fixed top-0 left-0 flex h-12 w-full w-screen items-center justify-between px-4">
+        <Logo />
+        <div className="flex items-center">
+          <Tooltip title="Visit DeerFlow on GitHub">
+            <Button variant="ghost" size="icon" asChild>
+              <Link
+                href="https://github.com/bytedance/deer-flow"
+                target="_blank"
+              >
+                <GithubOutlined />
+              </Link>
+            </Button>
+          </Tooltip>
+          <ThemeToggle />
+          {!isReplay && <SettingsDialog />}
+        </div>
+      </header>
+      <div
+        className={cn(
+          "flex h-full w-full justify-center px-4 pt-12 pb-4",
+          doubleColumnMode && "gap-8",
+        )}
+      >
+        <MessagesBlock
+          className={cn(
+            "shrink-0 transition-all duration-300 ease-out",
+            !doubleColumnMode &&
+              `w-[768px] translate-x-[min(calc((100vw-538px)*0.75/2),960px/2)]`,
+            doubleColumnMode && `w-[538px]`,
+          )}
+        />
+        <ResearchBlock
+          className={cn(
+            "w-[min(calc((100vw-538px)*0.75),960px)] pb-4 transition-all duration-300 ease-out",
+            !doubleColumnMode && "scale-0",
+            doubleColumnMode && "",
+          )}
+          researchId={openResearchId}
+        />
+      </div>
+    </div>
+  );
+}

web/src/app/page.tsx

@@ -3,76 +3,15 @@
 
 "use client";
 
-import { GithubOutlined } from "@ant-design/icons";
+import dynamic from "next/dynamic";
-import Link from "next/link";
+import { Suspense } from "react";
-import { useEffect, useMemo } from "react";
 
-import { Button } from "~/components/ui/button";
+const App = dynamic(() => import("./app"), { ssr: false });
-import { useReplay } from "~/core/replay";
-import { sendMessage, useStore } from "~/core/store";
-import { cn } from "~/lib/utils";
-
-import { Logo } from "./_components/logo";
-import { MessagesBlock } from "./_components/messages-block";
-import { ResearchBlock } from "./_components/research-block";
-import { ThemeToggle } from "./_components/theme-toggle";
-import { Tooltip } from "./_components/tooltip";
-import { SettingsDialog } from "./_settings/dialogs/settings-dialog";
 
 export default function HomePage() {
-  const { isReplay } = useReplay();
-  const openResearchId = useStore((state) => state.openResearchId);
-  const doubleColumnMode = useMemo(
-    () => openResearchId !== null,
-    [openResearchId],
-  );
-  useEffect(() => {
-    if (isReplay) {
-      void sendMessage();
-    }
-  }, [isReplay]);
   return (
-    <div className="flex h-full w-full justify-center">
+    <Suspense fallback={<div>Loading DeerFlow...</div>}>
-      <header className="fixed top-0 left-0 flex h-12 w-full w-screen items-center justify-between px-4">
+      <App />
-        <Logo />
+    </Suspense>
-        <div className="flex items-center">
-          <Tooltip title="Visit DeerFlow on GitHub">
-            <Button variant="ghost" size="icon" asChild>
-              <Link
-                href="https://github.com/bytedance/deer-flow"
-                target="_blank"
-              >
-                <GithubOutlined />
-              </Link>
-            </Button>
-          </Tooltip>
-          <ThemeToggle />
-          {!isReplay && <SettingsDialog />}
-        </div>
-      </header>
-      <div
-        className={cn(
-          "flex h-full w-full justify-center px-4 pt-12 pb-4",
-          doubleColumnMode && "gap-8",
-        )}
-      >
-        <MessagesBlock
-          className={cn(
-            "shrink-0 transition-all duration-300 ease-out",
-            !doubleColumnMode &&
-              `w-[768px] translate-x-[min(calc((100vw-538px)*0.75/2),960px/2)]`,
-            doubleColumnMode && `w-[538px]`,
-          )}
-        />
-        <ResearchBlock
-          className={cn(
-            "w-[min(calc((100vw-538px)*0.75),960px)] pb-4 transition-all duration-300 ease-out",
-            !doubleColumnMode && "scale-0",
-            doubleColumnMode && "",
-          )}
-          researchId={openResearchId}
-        />
-      </div>
-    </div>
   );
 }