:root {
  --ink: #172033;
  --muted: #637083;
  --paper: #f8f9fb;
  --surface: #ffffff;
  --line: #dfe5ed;
  --blue: #1767d2;
  --blue-deep: #0d3d82;
  --blue-soft: #eaf3ff;
  --green: #16785a;
  --shadow: 0 24px 70px rgba(25, 45, 77, 0.1);
  --radius: 22px;
  --content: 1120px;
}

* {
  box-sizing: border-box;
}

html {
  color-scheme: light;
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--ink);
  background:
    radial-gradient(circle at 88% 4%, rgba(23, 103, 210, 0.12), transparent 28rem),
    linear-gradient(rgba(23, 103, 210, 0.028) 1px, transparent 1px),
    linear-gradient(90deg, rgba(23, 103, 210, 0.028) 1px, transparent 1px),
    var(--paper);
  background-size: auto, 32px 32px, 32px 32px, auto;
  font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", sans-serif;
  font-size: 16px;
  line-height: 1.8;
  -webkit-font-smoothing: antialiased;
}

a {
  color: var(--blue);
  text-underline-offset: 0.2em;
  text-decoration-thickness: 1px;
}

a:hover {
  color: var(--blue-deep);
}

a:focus-visible {
  outline: 3px solid rgba(23, 103, 210, 0.32);
  outline-offset: 4px;
  border-radius: 4px;
}

.skip-link {
  position: fixed;
  z-index: 20;
  top: 12px;
  left: 12px;
  padding: 9px 14px;
  color: #fff;
  background: var(--ink);
  border-radius: 9px;
  transform: translateY(-160%);
}

.skip-link:focus {
  transform: translateY(0);
}

.site-header {
  position: relative;
  z-index: 5;
  border-bottom: 1px solid rgba(23, 32, 51, 0.1);
  background: rgba(248, 249, 251, 0.88);
  backdrop-filter: blur(18px);
}

.header-inner {
  width: min(calc(100% - 36px), var(--content));
  min-height: 78px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 28px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  color: var(--ink);
  text-decoration: none;
  font-weight: 760;
  letter-spacing: -0.02em;
}

.brand-mark {
  width: 39px;
  height: 39px;
  display: grid;
  place-items: center;
  color: #fff;
  background: var(--blue);
  border-radius: 12px;
  box-shadow: 0 10px 22px rgba(23, 103, 210, 0.24);
  font-family: ui-serif, "Songti SC", serif;
  font-size: 22px;
}

.site-nav {
  display: flex;
  align-items: center;
  gap: 8px;
  overflow-x: auto;
  scrollbar-width: none;
}

.site-nav a {
  flex: 0 0 auto;
  padding: 7px 11px;
  color: var(--muted);
  border-radius: 9px;
  font-size: 14px;
  text-decoration: none;
}

.site-nav a:hover,
.site-nav a[aria-current="page"] {
  color: var(--blue-deep);
  background: var(--blue-soft);
}

.hero {
  width: min(calc(100% - 36px), var(--content));
  margin: 0 auto;
  padding: 74px 0 46px;
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(280px, 0.58fr);
  gap: 48px;
  align-items: end;
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin: 0 0 18px;
  color: var(--blue-deep);
  font-size: 13px;
  font-weight: 750;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.eyebrow::before {
  content: "";
  width: 28px;
  height: 2px;
  background: var(--blue);
}

h1,
h2,
h3 {
  font-family: ui-serif, "Songti SC", "STSong", serif;
  text-wrap: balance;
}

h1 {
  max-width: 780px;
  margin: 0;
  font-size: clamp(42px, 6.8vw, 78px);
  line-height: 1.06;
  letter-spacing: -0.055em;
}

.hero-copy {
  max-width: 720px;
  margin: 24px 0 0;
  color: var(--muted);
  font-size: clamp(17px, 2vw, 20px);
  line-height: 1.75;
}

.version-card {
  padding: 25px;
  background: var(--ink);
  color: #fff;
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

.version-card span {
  display: block;
  color: #afc2dc;
  font-size: 12px;
  letter-spacing: 0.08em;
}

.version-card strong {
  display: block;
  margin: 5px 0 15px;
  font-size: 18px;
}

.version-card p {
  margin: 0;
  color: #d9e4f2;
  font-size: 14px;
  line-height: 1.65;
}

.trust-strip {
  width: min(calc(100% - 36px), var(--content));
  margin: 0 auto 54px;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  overflow: hidden;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 18px;
  box-shadow: 0 12px 40px rgba(25, 45, 77, 0.06);
}

.trust-item {
  min-height: 108px;
  padding: 21px 24px;
  display: flex;
  align-items: center;
  gap: 14px;
}

.trust-item + .trust-item {
  border-left: 1px solid var(--line);
}

.trust-number {
  flex: 0 0 auto;
  width: 34px;
  height: 34px;
  display: grid;
  place-items: center;
  color: var(--blue-deep);
  background: var(--blue-soft);
  border-radius: 50%;
  font-weight: 800;
}

.trust-item strong,
.trust-item small {
  display: block;
}

.trust-item small {
  margin-top: 2px;
  color: var(--muted);
  line-height: 1.45;
}

.document-layout {
  width: min(calc(100% - 36px), var(--content));
  margin: 0 auto 92px;
  display: grid;
  grid-template-columns: 230px minmax(0, 1fr);
  gap: 38px;
  align-items: start;
}

.toc {
  position: sticky;
  top: 26px;
  padding: 18px;
  background: rgba(255, 255, 255, 0.82);
  border: 1px solid var(--line);
  border-radius: 16px;
  backdrop-filter: blur(12px);
}

.toc strong {
  display: block;
  margin-bottom: 10px;
  font-size: 13px;
  letter-spacing: 0.08em;
}

.toc a {
  display: block;
  min-height: 40px;
  padding: 8px;
  color: var(--muted);
  border-radius: 7px;
  font-size: 13px;
  line-height: 1.45;
  text-decoration: none;
}

.toc a:hover {
  color: var(--blue-deep);
  background: var(--blue-soft);
}

.document {
  min-width: 0;
  padding: clamp(26px, 5vw, 62px);
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 28px;
  box-shadow: var(--shadow);
}

.document section {
  scroll-margin-top: 24px;
}

.document section + section {
  margin-top: 48px;
  padding-top: 44px;
  border-top: 1px solid var(--line);
}

.document h2 {
  margin: 0 0 19px;
  font-size: clamp(25px, 3.5vw, 34px);
  line-height: 1.3;
  letter-spacing: -0.025em;
}

.document p {
  margin: 0 0 14px;
  color: #354155;
}

.document p:last-child {
  margin-bottom: 0;
}

.identity-box,
.callout {
  margin: 22px 0;
  padding: 20px 22px;
  background: var(--blue-soft);
  border-left: 4px solid var(--blue);
  border-radius: 4px 14px 14px 4px;
}

.identity-box dl {
  margin: 0;
  display: grid;
  grid-template-columns: 110px minmax(0, 1fr);
  gap: 7px 16px;
}

.identity-box dt {
  color: var(--muted);
}

.identity-box dd {
  margin: 0;
  font-weight: 700;
  overflow-wrap: anywhere;
}

.link-list {
  margin: 18px 0 0;
  padding: 0;
  list-style: none;
}

.link-list li + li {
  margin-top: 8px;
}

.link-list a::after {
  content: " ↗";
  font-size: 0.8em;
}

.document p > a,
.link-list a {
  min-height: 44px;
  display: inline-flex;
  align-items: center;
}

.doc-cards {
  width: min(calc(100% - 36px), var(--content));
  margin: 0 auto 90px;
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 18px;
}

.doc-card {
  min-height: 220px;
  padding: 28px;
  display: flex;
  flex-direction: column;
  color: var(--ink);
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 20px;
  text-decoration: none;
  transition: transform 180ms ease, box-shadow 180ms ease, border-color 180ms ease;
}

.doc-card:hover {
  color: var(--ink);
  border-color: rgba(23, 103, 210, 0.38);
  box-shadow: 0 16px 40px rgba(25, 45, 77, 0.09);
  transform: translateY(-3px);
}

.doc-card small {
  color: var(--blue);
  font-weight: 750;
}

.doc-card h2 {
  margin: 18px 0 8px;
  font-size: 29px;
}

.doc-card p {
  margin: 0;
  color: var(--muted);
}

.doc-card span {
  margin-top: auto;
  padding-top: 22px;
  color: var(--blue-deep);
  font-weight: 700;
}

.site-footer {
  border-top: 1px solid var(--line);
  background: #f1f4f8;
}

.footer-inner {
  width: min(calc(100% - 36px), var(--content));
  min-height: 160px;
  margin: 0 auto;
  padding: 34px 0;
  display: flex;
  justify-content: space-between;
  gap: 30px;
  align-items: center;
}

.footer-inner p {
  margin: 4px 0;
  color: var(--muted);
  font-size: 14px;
}

.privacy-seal {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 8px 12px;
  color: var(--green);
  background: #eaf8f2;
  border: 1px solid #c8ebde;
  border-radius: 999px;
  font-size: 13px;
  font-weight: 750;
}

@media (max-width: 820px) {
  .header-inner {
    padding: 14px 0;
    align-items: flex-start;
    flex-direction: column;
    gap: 12px;
  }

  .site-nav {
    width: 100%;
  }

  .hero {
    padding-top: 52px;
    grid-template-columns: 1fr;
    gap: 28px;
  }

  .trust-strip,
  .doc-cards {
    grid-template-columns: 1fr;
  }

  .trust-item + .trust-item {
    border-top: 1px solid var(--line);
    border-left: 0;
  }

  .document-layout {
    grid-template-columns: 1fr;
  }

  .toc {
    position: static;
  }

  .footer-inner {
    align-items: flex-start;
    flex-direction: column;
  }
}

@media (max-width: 520px) {
  body {
    font-size: 15px;
  }

  .hero {
    padding-top: 42px;
  }

  .document {
    border-radius: 20px;
  }

  .identity-box dl {
    grid-template-columns: 1fr;
    gap: 1px;
  }

  .identity-box dd + dt {
    margin-top: 9px;
  }
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  .doc-card {
    transition: none;
  }
}

@media print {
  body {
    background: #fff;
  }

  .site-header,
  .toc,
  .trust-strip,
  .site-footer {
    display: none;
  }

  .hero,
  .document-layout {
    width: 100%;
    display: block;
  }

  .hero {
    padding: 0 0 24px;
  }

  .version-card {
    margin-top: 20px;
    color: #000;
    background: #fff;
    border: 1px solid #bbb;
    box-shadow: none;
  }

  .version-card span,
  .version-card p {
    color: #333;
  }

  .document {
    padding: 0;
    border: 0;
    box-shadow: none;
  }
}