:root { --bg: #fff; --ink: #0a0a0b; --ink-2: #6e6e73; color-scheme: light dark; }
@media (prefers-color-scheme: dark) { :root { --bg: #000; --ink: #fff; --ink-2: #98989d; } }
* { box-sizing: border-box; }
body { margin: 0; min-height: 100vh; display: grid; place-items: center; padding: 24px 16px; background: var(--bg); color: var(--ink);
  font: 16px/1.5 -apple-system, BlinkMacSystemFont, "SF Pro Text", "Inter", "Segoe UI", Roboto, sans-serif; -webkit-font-smoothing: antialiased; }
main { max-width: 440px; text-align: center; }
.mark { width: 64px; height: 64px; border-radius: 16px; margin: 0 auto 20px; background: var(--ink); color: var(--bg); display: grid; place-items: center; font-size: 30px; font-weight: 700; }
h1 { font-size: 34px; letter-spacing: -0.03em; margin: 0 0 8px; }
p { color: var(--ink-2); margin: 0 0 28px; }
nav { display: flex; gap: 20px; justify-content: center; flex-wrap: wrap; }
a { color: var(--ink); font-weight: 500; text-underline-offset: 3px; }