:root {
  color-scheme: light dark;
  --bg: #ffffff;
  --fg: #1a1a1a;
  --muted: #6b7280;
  --accent: #2563eb;
}
@media (prefers-color-scheme: dark) {
  :root { --bg: #0b0d12; --fg: #f3f4f6; --muted: #9ca3af; --accent: #60a5fa; }
}
* { box-sizing: border-box; }
html, body { height: 100%; margin: 0; }
body {
  background: var(--bg);
  color: var(--fg);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  display: flex;
  align-items: center;
  justify-content: center;
}
.hero { text-align: center; padding: 2rem; }
.hero h1 {
  font-size: clamp(2.5rem, 8vw, 5rem);
  margin: 0 0 0.5rem;
  letter-spacing: -0.02em;
}
.tagline { font-size: 1.1rem; margin: 0 0 1.5rem; }
.meta { font-size: 0.85rem; color: var(--muted); margin: 0; }