feat(ui): add premium BenefitGrid to karriere page

Former-commit-id: b832e30800338c59f7d55e56a0bf30dd8b9b63aa

components/layout/Header.tsx

@@ -23,9 +23,14 @@ export function Header({ navLinks }: HeaderProps) {
   const [forceSolid, setForceSolid] = React.useState(false);
   const pathname = usePathname() || '/';
 
-  // Scroll bound shine effect
+  // Scroll bound shine effect (continuous looping as user scrolls)
   const { scrollY } = useScroll();
-  const shineX = useTransform(scrollY, [20, 600], ['-150%', '150%']);
+  const shineX = useTransform(scrollY, (y) => {
+    const adjustedY = Math.max(0, y - 20); // Start after the solid mode kicks in
+    const range = 800; // 1 full sweep per 800px scrolled
+    const progress = (adjustedY % range) / range;
+    return `${-150 + progress * 300}%`;
+  });
 
   // Determine current locale from pathname
   const currentLocale = pathname.startsWith('/en') ? 'en' : 'de';