diff --git a/frontend/src/app/workspace/agents/[agent_name]/chats/[thread_id]/page.tsx b/frontend/src/app/workspace/agents/[agent_name]/chats/[thread_id]/page.tsx
index 9b9cb59f..b7ed7305 100644
--- a/frontend/src/app/workspace/agents/[agent_name]/chats/[thread_id]/page.tsx
+++ b/frontend/src/app/workspace/agents/[agent_name]/chats/[thread_id]/page.tsx
@@ -166,7 +166,6 @@ export default function AgentChatPage() {
                   threadId={threadId}
                   autoFocus={isNewThread}
                   showWelcomeStyle={isNewThread}
-                  hasSubmitted={!isNewThread}
                   status={
                     thread.error
                       ? "error"
diff --git a/frontend/src/app/workspace/chats/[thread_id]/page.tsx b/frontend/src/app/workspace/chats/[thread_id]/page.tsx
index ad95d9f2..82d7f2cb 100644
--- a/frontend/src/app/workspace/chats/[thread_id]/page.tsx
+++ b/frontend/src/app/workspace/chats/[thread_id]/page.tsx
@@ -233,7 +233,6 @@ export default function ChatPage() {
     [thread.values.artifacts],
   );
 
-  const [hasSubmitted, setHasSubmitted] = useState(false);
   const [historyCutoff, setHistoryCutoff] = useState<number | null>(null);
 
   useEffect(() => {
@@ -241,7 +240,6 @@ export default function ChatPage() {
       setHistoryCutoff(null);
       return;
     }
-    if (hasSubmitted) return;
     // Welcome 态下、未提交前，把当前已有消息都当作“历史”切掉。
     // 这样即使历史消息是后续异步补齐，也不会重新露出。
     setHistoryCutoff((prev) => {
@@ -250,7 +248,6 @@ export default function ChatPage() {
       return next > prev ? next : prev;
     });
   }, [
-    hasSubmitted,
     historyCutoff,
     shouldRenderHistory,
     thread.isThreadLoading,
@@ -322,7 +319,6 @@ export default function ChatPage() {
       if (isNewThread && safeThreadId && !isThreadInitReady) {
         return;
       }
-      setHasSubmitted(true);
       if (safeThreadId && (isNewThread || showWelcomeStyle)) {
         router.replace(`/workspace/chats/${safeThreadId}?is_chatting=true`);
       }
@@ -343,22 +339,6 @@ export default function ChatPage() {
     await thread.stop();
   }, [thread]);
 
-  const resetNewSessionState = useCallback(() => {
-    setIsNewThread(true);
-    setHasSubmitted(false);
-    setHistoryCutoff(null);
-    setArtifacts([]);
-    deselectArtifact();
-    setArtifactsOpen(false);
-    setArtifactsFullscreen(false);
-  }, [
-    deselectArtifact,
-    setArtifacts,
-    setArtifactsFullscreen,
-    setArtifactsOpen,
-    setIsNewThread,
-  ]);
-
   return (
     <ThreadContext.Provider value={{ threadId, thread }}>
       <div
@@ -379,7 +359,7 @@ export default function ChatPage() {
               <header
                 className={cn(
                   "bg-background absolute top-0 right-0 left-0 z-30 mx-4 grid h-[58px] shrink-0 grid-cols-3 items-center border-b transition-all duration-300 ease-in-out",
-                  showWelcomeStyle && !hasSubmitted ? "hidden" : "",
+                  showWelcomeStyle ? "hidden" : "",
                 )}
               >
                 <div className="flex items-center justify-start overflow-hidden text-sm font-medium">
@@ -466,16 +446,14 @@ export default function ChatPage() {
               <main
                 className={cn(
                   "flex min-h-0 max-w-full grow flex-col",
-                  showWelcomeStyle && !hasSubmitted
-                    ? "bg-ws-surface-base"
-                    : "bg-background",
+                  showWelcomeStyle ? "bg-ws-surface-base" : "bg-background",
                 )}
               >
                 <div className="flex size-full justify-center">
                   <MessageList
                     className={cn(
                       "size-full",
-                      (!showWelcomeStyle || hasSubmitted) && "pt-[58px]",
+                      !showWelcomeStyle && "pt-[58px]",
                     )}
                     threadId={threadId}
                     thread={thread}
@@ -508,7 +486,7 @@ export default function ChatPage() {
             <div
               className={cn(
                 "h-full w-full transition-transform duration-300 ease-in-out",
-                showWelcomeStyle && !hasSubmitted ? "translate-x-0" : "",
+                showWelcomeStyle ? "translate-x-0" : "",
                 artifactPanelOpen ? "translate-x-0" : "translate-x-full",
               )}
             >
@@ -570,9 +548,7 @@ export default function ChatPage() {
           <div
             className={cn(
               "pointer-events-auto relative w-full max-w-[720px]",
-              showWelcomeStyle &&
-                !hasSubmitted &&
-                "-translate-y-[calc(50vh-96px)]",
+              showWelcomeStyle && "-translate-y-[calc(50vh-96px)]",
             )}
           >
             {!(showWelcomeStyle && thread.isThreadLoading) ? (
@@ -581,7 +557,6 @@ export default function ChatPage() {
                   className={cn("w-full rounded-[20px] bg-ws-surface-elevated")}
                   threadId={threadId}
                   showWelcomeStyle={showWelcomeStyle}
-                  hasSubmitted={hasSubmitted}
                   autoFocus={showWelcomeStyle}
                   status={
                     thread.error
@@ -593,9 +568,7 @@ export default function ChatPage() {
                   context={settings.context}
                   extraHeader={
                     <div className="flex flex-col gap-4">
-                      {showWelcomeStyle && !hasSubmitted && (
-                        <Welcome mode={settings.context.mode} />
-                      )}
+                      {showWelcomeStyle && <Welcome mode={settings.context.mode} />}
                     </div>
                   }
                   disabled={
diff --git a/frontend/src/components/workspace/input-box.tsx b/frontend/src/components/workspace/input-box.tsx
index 49ebc4f5..85d2ddb1 100644
--- a/frontend/src/components/workspace/input-box.tsx
+++ b/frontend/src/components/workspace/input-box.tsx
@@ -219,7 +219,6 @@ export function InputBox({
   context,
   extraHeader,
   showWelcomeStyle,
-  hasSubmitted,
   initialValue,
   onContextChange,
   onSubmit,
@@ -238,7 +237,6 @@ export function InputBox({
   };
   extraHeader?: React.ReactNode;
   showWelcomeStyle: boolean;
-  hasSubmitted?: boolean;
   initialValue?: string;
   onContextChange?: (
     context: Omit<
@@ -294,14 +292,13 @@ export function InputBox({
   const [isInputToolsTourReady, setIsInputToolsTourReady] = useState(false);
   const { data: referenceFilesData } = useReferenceFiles(threadIdFromProps);
 
-  // isNewThread 时禁用收缩，始终保持展开（除非已提交消息）
-  const effectiveIsFocused =
-    ((showWelcomeStyle ?? false) && !hasSubmitted) || isFocused;
+  // Welcome 态下禁用收缩，始终保持展开
+  const effectiveIsFocused = (showWelcomeStyle ?? false) || isFocused;
   const shouldShowSuggestionList =
-    showWelcomeStyle && !hasSubmitted && searchParams.get("mode") !== "skill";
+    showWelcomeStyle && searchParams.get("mode") !== "skill";
 
   useEffect(() => {
-    if (!showWelcomeStyle || hasSubmitted) {
+    if (!showWelcomeStyle) {
       setIsInputToolsTourReady(false);
       return;
     }
@@ -318,14 +315,13 @@ export function InputBox({
     return () => window.cancelAnimationFrame(frameId);
   }, [
     showWelcomeStyle,
-    hasSubmitted,
     shouldShowSuggestionList,
     iframeSkill.isBootstrapping,
     iframeSkill.selectedSkills.length,
   ]);
 
   useEffect(() => {
-    if (!showWelcomeStyle || hasSubmitted || !isInputToolsTourReady) {
+    if (!showWelcomeStyle || !isInputToolsTourReady) {
       setIsInputToolsTourOpen(false);
       return;
     }
@@ -337,7 +333,7 @@ export function InputBox({
     if (!hasSeenTourForCurrentThread) {
       setIsInputToolsTourOpen(true);
     }
-  }, [showWelcomeStyle, hasSubmitted, isInputToolsTourReady, threadId]);
+  }, [showWelcomeStyle, isInputToolsTourReady, threadId]);
 
   const finishInputToolsTour = useCallback(() => {
     const seenState = parseInputToolsTourSeenState(
@@ -817,7 +813,6 @@ export function InputBox({
           "border-0 rounded-[20px] backdrop-blur-sm",
           "transition-[height] duration-300 ease-out shadow-none ",
           !showWelcomeStyle && "h-[200px] shadow-[0_0_20px_0_rgba(0,0,0,0.10)]",
-          hasSubmitted && "shadow-[0_0_20px_0_rgba(0,0,0,0.10)]!",
           effectiveIsFocused ? "h-[200px]" : "h-[80px]",
         )}
         disabled={isInputDisabled}