style: narrow content column to max-w-3xl for centered layout

src/app/layout.tsx

@@ -39,7 +39,7 @@ export default function RootLayout({
       >
         <ThemeProvider>
           <Nav />
-          <main className="max-w-5xl mx-auto px-6 py-14">
+          <main className="max-w-3xl mx-auto px-6 py-14">
             {children}
           </main>
           <Footer />

src/components/Footer.tsx

@@ -1,7 +1,7 @@
 export default function Footer() {
   return (
     <footer className="border-t border-[var(--color-border)] py-5 mt-8">
-      <div className="max-w-5xl mx-auto px-6 flex items-center justify-between">
+      <div className="max-w-3xl mx-auto px-6 flex items-center justify-between">
         <span className="font-mono text-xs text-[var(--color-text-dim)]">
           &copy; {new Date().getFullYear()} Tyler Koenig
         </span>

src/components/Nav.tsx

@@ -13,7 +13,7 @@ export default function Nav() {
   const pathname = usePathname();
   return (
     <header className="sticky top-0 z-50 bg-[var(--color-surface)] border-b border-[var(--color-border)]">
-      <nav className="max-w-5xl mx-auto px-6 h-11 flex items-center justify-between">
+      <nav className="max-w-3xl mx-auto px-6 h-11 flex items-center justify-between">
         <Link
           href="/"
           className="font-mono text-sm font-bold text-[var(--color-text)] tracking-widest hover:text-[var(--color-text-label)]"