feat(404): restyle not-found for blacksite shell

app/not-found.tsx

@@ -4,14 +4,29 @@ export const metadata = { title: "Not Found" }
 
 export default function NotFound() {
   return (
-    <main className="min-h-screen flex items-center justify-center px-6">
+    <main className="flex min-h-screen items-center justify-center bg-blacksite-bg px-6 text-blacksite-text">
-      <div className="text-center">
+      <div className="w-full max-w-2xl border border-blacksite-line bg-blacksite-surface/60 p-8 shadow-2xl shadow-black/40 sm:p-12">
-        <p className="font-mono text-sm text-ink-soft mb-4">404</p>
+        <p className="section-label mb-5">SIGNAL LOST /.404</p>
-        <h1 className="heading-xl text-ink mt-0 mb-4">Page not found</h1>
+        <h1 className="mb-5 font-display text-5xl font-semibold tracking-tight text-blacksite-text sm:text-7xl">
-        <p className="text-ink-soft mb-8">The page you{`'`}re looking for doesn{`'`}t exist.</p>
+          Route dissolved into static.
-        <Link href="/" className="inline-block rounded-lg bg-ink px-6 py-3 text-sm font-medium text-canvas hover:opacity-80 transition-opacity">
+        </h1>
-          Go home
+        <p className="mb-8 max-w-lg text-sm leading-6 text-blacksite-muted sm:text-base">
+          This coordinate is dark; return to base or scan the field notes.
+        </p>
+        <div className="flex flex-wrap gap-3">
+          <Link
+            href="/"
+            className="border border-signal-orange px-4 py-3 font-mono text-xs uppercase tracking-[0.16em] text-signal-orange transition-colors hover:bg-signal-orange hover:text-blacksite-bg focus-visible:bg-signal-orange focus-visible:text-blacksite-bg"
+          >
+            Return home
           </Link>
+          <Link
+            href="/blog/"
+            className="border border-blacksite-line px-4 py-3 font-mono text-xs uppercase tracking-[0.16em] text-blacksite-text transition-colors hover:border-signal-cyan hover:text-signal-cyan focus-visible:border-signal-cyan focus-visible:text-signal-cyan"
+          >
+            Field notes
+          </Link>
+        </div>
       </div>
     </main>
   )