perf: compress hero image and defer page transition shutter

app/[locale]/layout.tsx

@@ -21,7 +21,7 @@ import { DynamicInitialLoader as InitialLoader } from '@/components/providers/Dy
 import { DynamicMobileBottomNav as MobileBottomNav } from '@/components/layout/DynamicMobileBottomNav';
 
 import { DynamicCorporateBackground as CorporateBackground } from '@/components/decorations/DynamicCorporateBackground';
-import { DynamicPageTransitionShutter as PageTransitionShutter } from '@/components/providers/DynamicPageTransitionShutter';
+const corporateBackground = null; // Removed to prevent line shifting
 
 const inter = Inter({
   subsets: ['latin'],
@@ -192,7 +192,7 @@ export default async function Layout(props: {
           <TransitionProvider>
             <CorporateBackground />
             <InitialLoader shouldShowLoader={!hasSeenLoader} />
-            <PageTransitionShutter />
+            {/* PageTransitionShutter loaded dynamically in TransitionProvider */}
             <SkipLink />
             <Header navLinks={navLinks} />
             <MobileBottomNav navLinks={navLinks} currentLocale={safeLocale} />

app/[locale]/page.tsx

@@ -133,7 +133,12 @@ export default async function Home(props: { params: Promise<{ locale: string }>
   
   setRequestLocale(locale);
   preload('/germany-map.svg', { as: 'image', fetchPriority: 'high' });
-  preload('/assets/videos/web/hero-kabelpflug-poster.webp', { as: 'image', fetchPriority: 'high' });
+  preload('/assets/videos/web/hero-kabelpflug-poster.webp', { 
+    as: 'image', 
+    fetchPriority: 'high',
+    imageSrcSet: '/assets/videos/web/hero-kabelpflug-poster-mobile.webp 800w, /assets/videos/web/hero-kabelpflug-poster.webp 1920w',
+    imageSizes: '(max-width: 768px) 800px, 1920px'
+  });
 
   const mdx = await getMdxContent(locale, 'home');
   const allReferences = await getAllReferences(locale);

components/blocks/HeroVideo.tsx

@@ -80,10 +80,11 @@ export function HeroVideo(props: HeroVideoProps) {
       {/* Background color while video loads */}
       <div className="absolute inset-0 z-0 bg-neutral-dark" />
       
-      {/* ALWAYS render a native img as the LCP element to avoid Render Delay */}
       <img
         key={`img-${pathname}-${posterSrc}`}
         src={posterSrc}
+        srcSet={posterSrc.includes('-poster.webp') ? `${posterSrc.replace('-poster.webp', '-poster-mobile.webp')} 800w, ${posterSrc} 1920w` : undefined}
+        sizes={posterSrc.includes('-poster.webp') ? "(max-width: 768px) 800px, 1920px" : undefined}
         alt={posterAlt}
         className="absolute inset-0 w-full h-full object-cover z-[1] pointer-events-none"
         decoding="sync"

components/providers/TransitionProvider.tsx

@@ -3,9 +3,16 @@
 import React, { createContext, useContext, useState, useCallback, ReactNode, useEffect } from 'react';
 import { useRouter, usePathname, useSearchParams } from 'next/navigation';
 import { LazyMotion } from 'framer-motion';
+import dynamic from 'next/dynamic';
 
 const loadFeatures = () => import('@/lib/framer-features').then(res => res.default);
 
+// Defer loading the shutter to eliminate AnimatePresence from the initial bundle
+const DynamicPageTransitionShutter = dynamic(
+  () => import('./PageTransitionShutter').then(mod => mod.PageTransitionShutter),
+  { ssr: false }
+);
+
 interface TransitionContextType {
   isTransitioning: boolean;
   transitionMessage: string | null;
@@ -17,8 +24,18 @@ const TransitionContext = createContext<TransitionContextType | undefined>(undef
 export function TransitionProvider({ children }: { children: ReactNode }) {
   const [isTransitioning, setIsTransitioning] = useState(false);
   const [transitionMessage, setTransitionMessage] = useState<string | null>(null);
+  const [hasMountedShutter, setHasMountedShutter] = useState(false);
   const router = useRouter();
 
+  // Load the heavy shutter chunk in the background when the main thread is idle
+  useEffect(() => {
+    if (typeof window !== 'undefined' && 'requestIdleCallback' in window) {
+      window.requestIdleCallback(() => setHasMountedShutter(true));
+    } else {
+      setTimeout(() => setHasMountedShutter(true), 2000);
+    }
+  }, []);
+
   // We use a ref to track transition state without triggering the route change effect when it turns true
   const isTransitioningRef = React.useRef(isTransitioning);
   useEffect(() => {
@@ -44,6 +61,7 @@ export function TransitionProvider({ children }: { children: ReactNode }) {
 
     setTransitionMessage(message);
     setIsTransitioning(true);
+    setHasMountedShutter(true);
 
     // Die Animation des Shutters abwarten (ca. 700ms), dann pushen
     setTimeout(() => {
@@ -72,6 +90,7 @@ export function TransitionProvider({ children }: { children: ReactNode }) {
         />
       </React.Suspense>
       <LazyMotion features={loadFeatures}>
+        {hasMountedShutter && <DynamicPageTransitionShutter />}
         {children}
       </LazyMotion>
     </TransitionContext.Provider>