diff --git a/frontend/src/features/chat/components/ChatMessage.tsx b/frontend/src/features/chat/components/ChatMessage.tsx
index 3141b53..0f57969 100644
--- a/frontend/src/features/chat/components/ChatMessage.tsx
+++ b/frontend/src/features/chat/components/ChatMessage.tsx
@@ -22,7 +22,7 @@ export function ChatMessage() {
           스크롤 시 여백도 함께 밀려 올라가도록 스크롤 컨테이너 안쪽에 둔다 */}
       <div
         ref={scrollRef}
-        className="chat-scroll h-full overflow-y-auto flex flex-col pt-4 lg:pt-[64px] pb-6 px-4 sm:px-6 min-[1180px]:pl-[80px] min-[1180px]:pr-[72px] min-[1350px]:pl-[140px] min-[1350px]:pr-[126px]"
+        className="chat-scroll h-full overflow-y-auto flex flex-col pt-0 lg:pt-[64px] pb-6 px-4 sm:px-6 min-[1180px]:pl-[80px] min-[1180px]:pr-[72px] min-[1350px]:pl-[140px] min-[1350px]:pr-[126px]"
       >
         <ChatList scrollRef={scrollRef} />
       </div>
diff --git a/frontend/src/features/chat/components/RemainingTime.tsx b/frontend/src/features/chat/components/RemainingTime.tsx
index b507076..4f4355f 100644
--- a/frontend/src/features/chat/components/RemainingTime.tsx
+++ b/frontend/src/features/chat/components/RemainingTime.tsx
@@ -20,12 +20,23 @@ export function RemainingTime() {
   return (
     <span
       className={cn(
-        'inline-flex items-center gap-1.5 rounded-full px-3 py-1 text-xs font-bold whitespace-nowrap tabular-nums',
+        // min-w-0 + truncate: 헤더가 좁아도 잘려나가지 않고 말줄임으로 접힌다.
+        'inline-flex min-w-0 shrink items-center gap-1.5 rounded-full px-3 py-1 text-xs font-bold tabular-nums',
         ended ? 'bg-neutral-20 text-neutral-60' : 'bg-brand-light text-brand-600',
       )}
     >
-      <Clock className="size-3.5" />
-      협상 마감 {remaining}
+      <Clock className="size-3.5 shrink-0" />
+      <span className="truncate">
+        {ended ? (
+          // 종료 시엔 어느 폭에서도 긴 문장('종료되었습니다.')을 쓰지 않는다 — 헤더에서 잘리던 원인.
+          '마감 종료'
+        ) : (
+          <>
+            <span className="hidden sm:inline">협상 마감 </span>
+            {remaining}
+          </>
+        )}
+      </span>
     </span>
   )
 }
diff --git a/frontend/src/layouts/MainHeaderBar.tsx b/frontend/src/layouts/MainHeaderBar.tsx
index e7b1e1b..d47b808 100644
--- a/frontend/src/layouts/MainHeaderBar.tsx
+++ b/frontend/src/layouts/MainHeaderBar.tsx
@@ -1,9 +1,11 @@
 import { type ReactNode } from 'react'
 import { cn } from '@/lib'
 
-// safe-t: 노치 기기에서 헤더가 상태바 밑으로 파고들지 않도록 안전영역만큼 키운다(h-[56px] 은 콘텐츠 높이).
+// safe-t: 노치 기기에서 헤더가 상태바 밑으로 파고들지 않도록 안전영역만큼 키운다.
+// box-content 금지 — w-full + px-* 와 겹치면 폭이 "부모100% + 좌우패딩"이 되어 오른쪽이 잘린다.
+// 대신 border-box(기본) 유지하고 min-h 로 56px + 안전영역을 확보한다.
 const HEADER_BASE =
-  'flex w-full h-[56px] box-content safe-t items-center bg-white text-foreground border-b border-border'
+  'flex w-full min-h-[calc(56px+env(safe-area-inset-top))] safe-t items-center bg-white text-foreground border-b border-border'
 
 const HEADER_ALIGN = {
   left: 'justify-start',
diff --git a/frontend/src/pages/ChatPage.tsx b/frontend/src/pages/ChatPage.tsx
index 5f6a1cd..a4c0a25 100644
--- a/frontend/src/pages/ChatPage.tsx
+++ b/frontend/src/pages/ChatPage.tsx
@@ -25,8 +25,9 @@ export function ChatPage() {
         sidebar={<Sidebar />}
         header={
           <MainHeaderBar className="px-4 sm:px-6 min-[1180px]:px-8">
-            <div className="flex w-full items-center justify-between gap-2">
-              <div className="flex min-w-0 items-center gap-2">
+            {/* min-w-0: flex 기본 min-width:auto 라 자식이 안 줄어들어 헤더 밖으로 넘치던 것 방지 */}
+            <div className="flex w-full min-w-0 items-center justify-between gap-2">
+              <div className="flex min-w-0 shrink items-center gap-2">
                 <BackToListButton />
                 <span className="hidden h-4 w-px bg-border lg:inline-block" />
                 <span className="hidden size-2 shrink-0 rounded-full bg-brand-600 animate-pulse lg:inline-block" />
@@ -34,7 +35,7 @@ export function ChatPage() {
                   실시간 구매 협상 채널
                 </span>
               </div>
-              <div className="flex items-center gap-1.5">
+              <div className="flex min-w-0 shrink items-center gap-1.5">
                 <PanelToggle icon={<Package className="size-4" />} label="상품" panel="product" />
                 <PanelToggle icon={<ClipboardList className="size-4" />} label="현황" panel="status" />
                 <RemainingTime />
@@ -92,7 +93,7 @@ function PanelToggle({
       type="button"
       onClick={() => open(panel)}
       className={cn(
-        'flex items-center gap-1 rounded-lg border border-border px-2 py-1.5 text-xs font-bold text-neutral-70 hover:bg-neutral-10 lg:hidden',
+        'flex shrink-0 items-center gap-1 rounded-lg border border-border px-2 py-1.5 text-xs font-bold text-neutral-70 hover:bg-neutral-10 lg:hidden',
         interactive,
       )}
     >
diff --git a/landing/app/components/sections/hero-neumorphic.tsx b/landing/app/components/sections/hero-neumorphic.tsx
index 648afae..8793f8f 100644
--- a/landing/app/components/sections/hero-neumorphic.tsx
+++ b/landing/app/components/sections/hero-neumorphic.tsx
@@ -57,8 +57,8 @@ export function HeroNeumorphic() {
             className="w-full flex justify-center"
           >
             <video
-              src="/gifs/negotiation_annotated.mp4"
-              poster="/gifs/negotiation_annotated.jpg"
+              src="/gifs/negotiation_annotated_3d.mp4?v=w3"
+              poster="/gifs/negotiation_annotated_3d.jpg?v=w3"
               autoPlay
               muted
               loop
diff --git a/landing/app/components/sections/how-it-works-demo.tsx b/landing/app/components/sections/how-it-works-demo.tsx
index 6810537..64dbbd2 100644
--- a/landing/app/components/sections/how-it-works-demo.tsx
+++ b/landing/app/components/sections/how-it-works-demo.tsx
@@ -241,8 +241,6 @@ const DEMO_TABS: DemoTab[] = [
     checks: ["1:1 비대면 협상 포털 제공", "불필요한 실랑이를 예방하여 파트너십 보호"],
     mockup: "phone",
     gif: "/gifs/negotiation.gif",
-    video: "/gifs/negotiation.mp4",
-    poster: "/gifs/negotiation.jpg",
     gifAlt: "AI 모바일 자동 협상 시연",
     fallback: {
       icon: Smartphone,
diff --git a/landing/app/components/ui/device-mockups.tsx b/landing/app/components/ui/device-mockups.tsx
index 3e3781e..cad6f64 100644
--- a/landing/app/components/ui/device-mockups.tsx
+++ b/landing/app/components/ui/device-mockups.tsx
@@ -23,11 +23,11 @@ function BrowserFrame({ url, children }: { url: string; children: React.ReactNod
 function PhoneFrame({ children }: { children: React.ReactNode }) {
   return (
     <div className="relative bg-black rounded-[48px] p-3 shadow-[0_20px_50px_rgba(0,0,0,0.15)] border-4 border-line-strong w-full max-w-[290px] aspect-[9/18] overflow-hidden flex flex-col">
-      <div className="absolute top-4 left-1/2 -translate-x-1/2 bg-black h-5 w-28 rounded-full z-20 flex items-center justify-around px-4">
-        <span className="w-1.5 h-1.5 rounded-full bg-[#1F2022]" />
-        <span className="w-10 h-1 bg-[#1F2022] rounded-full" />
+      {/* 노치는 화면 '안쪽'에 작은 아일랜드로 — 베젤과 붙으면 검은 덩어리처럼 보인다 */}
+      <div className="bg-white rounded-[36px] flex-1 overflow-hidden relative flex flex-col justify-center items-center">
+        <div className="absolute top-1 left-1/2 -translate-x-1/2 bg-black/70 h-0.5 w-3.5 rounded-full z-20" />
+        {children}
       </div>
-      <div className="bg-white rounded-[36px] flex-1 overflow-hidden relative flex flex-col justify-center items-center">{children}</div>
     </div>
   )
 }
diff --git a/landing/app/routes/home.tsx b/landing/app/routes/home.tsx
index 749f85c..1e45723 100644
--- a/landing/app/routes/home.tsx
+++ b/landing/app/routes/home.tsx
@@ -34,7 +34,7 @@ type HeroTheme = "neumorphic" | "glassmorphic" | "console";
 
 export default function Home() {
   // 히어로 디자인 비교용 — 스위처는 dev 에서만 노출, 배포본은 console(Live Console) 고정
-  const [heroTheme, setHeroTheme] = useState<HeroTheme>("console");
+  const [heroTheme, setHeroTheme] = useState<HeroTheme>("neumorphic");
 
   return (
     <div className="min-h-screen bg-white text-ink font-sans antialiased selection:bg-primary/10 selection:text-primary">
diff --git a/landing/public/gifs/negotiation_annotated_3d.jpg b/landing/public/gifs/negotiation_annotated_3d.jpg
index 54dfd87..6f0d01a 100644
Binary files a/landing/public/gifs/negotiation_annotated_3d.jpg and b/landing/public/gifs/negotiation_annotated_3d.jpg differ
diff --git a/landing/public/gifs/negotiation_annotated_3d.mp4 b/landing/public/gifs/negotiation_annotated_3d.mp4
index db711ee..d8598cd 100644
Binary files a/landing/public/gifs/negotiation_annotated_3d.mp4 and b/landing/public/gifs/negotiation_annotated_3d.mp4 differ