:root { color-scheme: light; --ink:#0b1220; --muted:#64748b; --primary:#2563eb; --line:rgba(15,23,42,.10); }
  * { box-sizing:border-box; }
  body { margin:0; font-family:Inter, "Noto Sans SC", "PingFang SC", "Microsoft YaHei", Arial, sans-serif; color:var(--ink); background:#f8fbff; line-height:1.75; }
  .wrap { width:min(920px, calc(100% - 40px)); margin:0 auto; padding:48px 0 72px; }
  .nav { display:flex; justify-content:space-between; align-items:center; gap:20px; margin-bottom:56px; }
  .brand { display:flex; align-items:center; gap:10px; color:var(--ink); text-decoration:none; font-weight:800; }
  .brand img { width:32px; height:32px; }
  .back { color:var(--primary); text-decoration:none; font-weight:700; }
  main { padding:42px; border:1px solid var(--line); border-radius:22px; background:#fff; box-shadow:0 24px 70px rgba(37,99,235,.08); }
  h1 { margin:0 0 18px; font-size:clamp(32px, 5vw, 48px); line-height:1.12; letter-spacing:-.04em; }
  h2 { margin:34px 0 10px; font-size:22px; }
  p, li { color:var(--muted); }
  a { color:var(--primary); }
  @media (max-width:640px) { main { padding:28px 22px; } .nav { align-items:flex-start; flex-direction:column; } }