style(mobile): optimize mobile layout and component spacing

- Hide CorporateBackground on mobile to prevent content overlap
- Increase Header padding on mobile for better logo spacing
- Reduce top spacing in HeroSection on mobile
- Change SubCompanyTiles to horizontally scrollable row on mobile
- Add bottom padding to Footer to clear MobileBottomNav
- Reduce Footer Bento card padding for compact mobile view

components/decorations/CorporateBackground.tsx

@@ -78,7 +78,7 @@ export function CorporateBackground() {
   const y5 = useTransform(scrollYProgress, [0, 1], [0, -500]);
 
   return (
-    <div className="absolute inset-0 z-[50] overflow-hidden pointer-events-none" aria-hidden="true">
+    <div className="absolute inset-0 z-[50] overflow-hidden pointer-events-none hidden md:block" aria-hidden="true">
       {/* 1. Top Right - Medium, rotating moderately */}
       <motion.div 
         style={{