feat: polish motion with stronger easing, press feedback and reduced motion (#73)

- Override Tailwind ease-out/ease-in-out with stronger curves, add ease-drawer
- hoverOnlyWhenSupported so hover styles never stick on touch devices
- Replace transition-all with explicit properties across the public UI
- Press feedback via active:scale-[0.97] instead of hover:scale-105
- Global prefers-reduced-motion handling (CSS + MotionConfig reducedMotion="user")
- Mobile menu is a real drawer: stays mounted, inert when closed, Escape closes
- Progress and music bars animate scaleX/scaleY instead of width/height
- Fix undefined animate-spin-slow, contain hero CTA shine with overflow-hidden

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

app/components/Header.tsx

@@ -29,7 +29,7 @@ const Header = () => {
           {/* Logo Pill */}
           <Link
             href={`/${locale}`}
-            className="w-10 h-10 flex items-center justify-center rounded-full bg-stone-900 dark:bg-stone-50 text-white dark:text-stone-900 transition-transform hover:scale-105 active:scale-95 shadow-lg"
+            className="w-10 h-10 flex items-center justify-center rounded-full bg-stone-900 dark:bg-stone-50 text-white dark:text-stone-900 transition-transform duration-150 ease-out active:scale-[0.97] shadow-lg"
           >
             <span className="font-black text-xs tracking-tighter">dk0</span>
           </Link>
@@ -40,7 +40,7 @@ const Header = () => {
               <Link
                 key={item.name}
                 href={item.href}
-                className="px-5 py-2 text-[10px] font-black uppercase tracking-[0.2em] text-stone-500 hover:text-stone-900 dark:hover:text-stone-100 rounded-full transition-all"
+                className="px-5 py-2 text-[10px] font-black uppercase tracking-[0.2em] text-stone-500 hover:text-stone-900 dark:hover:text-stone-100 rounded-full transition-colors"
               >
                 {item.name}
               </Link>
@@ -62,7 +62,7 @@ const Header = () => {
             {/* Mobile Menu Toggle */}
             <button
               onClick={() => setIsOpen(!isOpen)}
-              className="w-8 h-8 flex md:hidden items-center justify-center text-stone-600 dark:text-stone-400 hover:bg-white dark:hover:bg-stone-800 rounded-full transition-colors shadow-sm"
+              className="w-8 h-8 flex md:hidden items-center justify-center text-stone-600 dark:text-stone-400 hover:bg-white dark:hover:bg-stone-800 rounded-full transition-[background-color,transform] duration-150 ease-out active:scale-[0.97] shadow-sm"
             >
               {isOpen ? <X size={14} /> : <Menu size={14} />}
             </button>
@@ -72,10 +72,10 @@ const Header = () => {
 
       {/* Mobile Menu Overlay */}
       <div
-        className={`fixed top-24 left-6 right-6 z-40 bg-white/90 dark:bg-stone-900/95 backdrop-blur-3xl border border-white/40 dark:border-white/10 rounded-[2.5rem] shadow-2xl p-6 md:hidden overflow-hidden transition-all duration-200 ${
+        className={`fixed top-24 left-6 right-6 z-40 bg-white/90 dark:bg-stone-900/95 backdrop-blur-3xl border border-white/40 dark:border-white/10 rounded-[2.5rem] shadow-2xl p-6 md:hidden overflow-hidden origin-top transition-[opacity,transform] duration-200 ease-out ${
           isOpen
-            ? "opacity-100 translate-y-0 pointer-events-auto"
-            : "opacity-0 -translate-y-2 pointer-events-none"
+            ? "opacity-100 translate-y-0 scale-100 pointer-events-auto"
+            : "opacity-0 -translate-y-2 scale-[0.97] pointer-events-none"
         }`}
       >
         <div className="flex flex-col gap-3">