fix: Use standard Tailwind classes instead of arbitrary values

- max-w-[640px] → max-w-2xl (672px)
- mt-[100px] → mt-24 (96px)

Standard classes are more performant in Tailwind v4

client/src/pages/DeployPage.tsx

@@ -124,8 +124,8 @@ export default function DeployPage() {
 
       <LanguageSelector currentLang={lang} onLangChange={setLang} />
 
-      <div className="relative z-10 w-full max-w-[640px] p-4 md:p-8">
+      <div className="relative z-10 w-full max-w-2xl p-4 md:p-8">
-        <header className="text-center mb-12 mt-[100px] md:mt-0">
+        <header className="text-center mb-12 mt-24 md:mt-0">
           <motion.h1
             initial={{ opacity: 0, y: -20 }}
             animate={{ opacity: 1, y: 0 }}