:root {
  color-scheme: dark;
  --bg: #070b0e;
  --card: #11181d;
  --text: #f4f7f8;
  --muted: #a3b0b8;
  --accent: #5eead4;
  --border: rgba(255, 255, 255, 0.12);
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  background: radial-gradient(circle at 15% 0%, #122831 0, var(--bg) 46rem);
  color: var(--text);
  font: 16px/1.75 -apple-system, BlinkMacSystemFont, "SF Pro Text", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
}
main {
  width: min(880px, calc(100% - 40px));
  margin: 0 auto;
  padding: 56px 0 80px;
}
.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 28px;
  color: var(--accent);
  font-weight: 700;
  letter-spacing: 0.02em;
  text-decoration: none;
}
.mark {
  display: inline-grid;
  place-items: center;
  width: 42px;
  height: 42px;
  border: 1px solid var(--border);
  border-radius: 14px;
  background: var(--card);
  font-size: 20px;
}
h1 {
  margin: 0 0 8px;
  font-size: clamp(28px, 5vw, 44px);
  line-height: 1.2;
  letter-spacing: -0.02em;
}
.subtitle { margin: 0 0 32px; color: var(--muted); }
h2 {
  margin: 30px 0 8px;
  font-size: 20px;
  line-height: 1.35;
}
p, li { color: #d9e2e6; }
ul { padding-left: 1.3rem; }
a { color: var(--accent); }
.card {
  margin-top: 18px;
  padding: 22px;
  border: 1px solid var(--border);
  border-radius: 22px;
  background: linear-gradient(180deg, rgba(255,255,255,0.04), rgba(255,255,255,0.015));
}
.nav {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin: 22px 0 0;
}
.nav a, .button {
  display: inline-block;
  padding: 10px 16px;
  border: 1px solid var(--border);
  border-radius: 999px;
  color: var(--text);
  text-decoration: none;
  background: rgba(255,255,255,0.045);
}
.nav a:hover, .button:hover { border-color: var(--accent); }
.meta { color: var(--muted); font-size: 14px; }
.notice {
  border-left: 3px solid var(--accent);
  padding: 10px 0 10px 16px;
  color: var(--muted);
}
footer {
  margin-top: 44px;
  padding-top: 22px;
  border-top: 1px solid var(--border);
  color: var(--muted);
  font-size: 14px;
}
@media (max-width: 540px) {
  main { padding-top: 32px; }
  .card { padding: 18px; }
}