:root {
  --brand: #273746;
  --learning: #1769e0;
  --gold: #b58a32;
  --canvas: #f6f8fc;
  --surface: #ffffff;
  --text: #17202a;
  --muted: #6f7a86;
  --line: rgba(39, 55, 70, 0.12);
  --shadow: 0 24px 70px rgba(39, 55, 70, 0.12);
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  color: var(--text);
  background: var(--canvas);
  font-family: -apple-system, BlinkMacSystemFont, "SF Pro Text", "PingFang SC", "Microsoft YaHei", sans-serif;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}
a { color: var(--learning); }
.shell { width: min(1080px, calc(100% - 40px)); margin: 0 auto; }
.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  background: rgba(246, 248, 252, 0.88);
  border-bottom: 1px solid var(--line);
  backdrop-filter: blur(18px);
}
.nav { min-height: 72px; display: flex; align-items: center; justify-content: space-between; gap: 24px; }
.brand { display: inline-flex; align-items: center; gap: 13px; color: var(--brand); text-decoration: none; font-weight: 700; }
.wordmark { width: 46px; height: 28px; color: var(--brand); }
.nav-links { display: flex; align-items: center; gap: 22px; font-size: 14px; }
.nav-links a { color: var(--muted); text-decoration: none; }
.nav-links a:hover { color: var(--brand); }
.hero { padding: 96px 0 76px; display: grid; grid-template-columns: 1.1fr 0.9fr; align-items: center; gap: 64px; }
.eyebrow { color: var(--gold); font-size: 13px; font-weight: 800; letter-spacing: 0.16em; text-transform: uppercase; }
h1, h2, h3 { color: var(--brand); line-height: 1.2; }
h1 { margin: 16px 0 20px; font-size: clamp(42px, 7vw, 74px); letter-spacing: -0.04em; }
h2 { margin: 0 0 18px; font-size: clamp(28px, 4vw, 42px); letter-spacing: -0.025em; }
h3 { margin: 0 0 8px; font-size: 20px; }
p { margin: 0 0 16px; }
.lead { max-width: 650px; color: var(--muted); font-size: 19px; }
.hero-card {
  min-height: 420px;
  display: grid;
  place-items: center;
  position: relative;
  overflow: hidden;
  border-radius: 42px;
  color: white;
  background: var(--brand);
  box-shadow: var(--shadow);
}
.hero-card::before, .hero-card::after { content: ""; position: absolute; border-radius: 999px; filter: blur(1px); }
.hero-card::before { width: 280px; height: 280px; top: -95px; right: -95px; background: rgba(23, 105, 224, 0.85); }
.hero-card::after { width: 230px; height: 230px; bottom: -105px; left: -70px; background: rgba(181, 138, 50, 0.56); }
.hero-logo { position: relative; z-index: 1; width: min(58%, 270px); color: white; filter: brightness(0) invert(1); }
.section { padding: 76px 0; }
.section-copy { max-width: 720px; color: var(--muted); }
.grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; margin-top: 34px; }
.card { padding: 28px; border: 1px solid var(--line); border-radius: 24px; background: var(--surface); }
.card p { color: var(--muted); }
.document {
  width: min(820px, calc(100% - 40px));
  margin: 64px auto;
  padding: clamp(28px, 6vw, 68px);
  border: 1px solid var(--line);
  border-radius: 30px;
  background: var(--surface);
  box-shadow: 0 18px 54px rgba(39, 55, 70, 0.08);
}
.document h1 { font-size: clamp(34px, 6vw, 54px); }
.document h2 { margin-top: 42px; font-size: 25px; }
.document h3 { margin-top: 28px; }
.document p, .document li { color: #44515d; }
.document li + li { margin-top: 8px; }
.updated { color: var(--muted); font-size: 14px; }
.faq { margin-top: 32px; }
.faq details { padding: 20px 0; border-top: 1px solid var(--line); }
.faq details:last-child { border-bottom: 1px solid var(--line); }
.faq summary { color: var(--brand); cursor: pointer; font-weight: 700; }
.faq details p { margin: 12px 0 0; }
.notice { margin-top: 30px; padding: 20px 22px; border-left: 4px solid var(--gold); border-radius: 12px; background: rgba(181, 138, 50, 0.08); }
.site-footer { padding: 34px 0 50px; color: var(--muted); border-top: 1px solid var(--line); font-size: 14px; }
.footer-row { display: flex; align-items: center; justify-content: space-between; gap: 20px; }
.footer-links { display: flex; gap: 18px; }
.footer-links a { color: var(--muted); text-decoration: none; }
@media (max-width: 760px) {
  .nav { align-items: flex-start; padding: 18px 0; }
  .nav-links { flex-wrap: wrap; justify-content: flex-end; gap: 8px 14px; }
  .hero { grid-template-columns: 1fr; padding-top: 58px; gap: 38px; }
  .hero-card { min-height: 330px; }
  .grid { grid-template-columns: 1fr; }
  .footer-row { align-items: flex-start; flex-direction: column; }
}