* { margin: 0; padding: 0; box-sizing: border-box; }
body {
  font-family: system-ui, -apple-system, "Segoe UI", "Microsoft YaHei", sans-serif;
  background: #0f172a; color: #e2e8f0; min-height: 100vh;
  display: flex; align-items: center; justify-content: center;
}
.hero { text-align: center; padding: 2rem; max-width: 640px; }
h1 { font-size: 2.6rem; font-weight: 700; letter-spacing: 0.02em; }
.tagline { margin-top: 0.9rem; font-size: 1.15rem; color: #94a3b8; }
.footer { margin-top: 2.4rem; font-size: 0.82rem; color: #475569; }