:root {
  color-scheme: dark;
  --bg: #0b1014;
  --surface: #10171c;
  --surface-soft: #0e1418;
  --line: #2b3941;
  --line-strong: #4a5b65;
  --text: #eff5f7;
  --muted: #aab8bf;
  --quiet: #7f8e96;
  --cyan: #52c7d0;
  --cyan-soft: #19383e;
  --focus: #a5eef3;
  font-family: "Microsoft YaHei UI", "Microsoft YaHei", system-ui, sans-serif;
  font-synthesis: none;
  text-rendering: optimizeLegibility;
}

* { box-sizing: border-box; }
html { min-width: 320px; background: var(--bg); }
body {
  min-width: 320px;
  min-height: 100vh;
  margin: 0;
  color: var(--text);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
}
a { color: inherit; }
a:focus-visible {
  outline: 2px solid var(--focus);
  outline-offset: 4px;
}

.site-shell {
  width: min(1080px, calc(100% - 48px));
  min-height: 100vh;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
}

.site-header {
  min-height: 78px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  border-bottom: 1px solid var(--line);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  min-height: 48px;
  text-decoration: none;
}

.brand-mark {
  width: 30px;
  height: 30px;
  display: grid;
  place-items: center;
  border: 1px solid var(--cyan);
  color: var(--cyan);
  font-weight: 800;
  font-size: 15px;
  letter-spacing: .05em;
}

.brand-copy { display: grid; gap: 3px; }
.brand-copy strong { font-size: 15px; line-height: 1.1; }
.brand-copy small,
.header-note,
.route-label,
.section-index,
dt {
  color: var(--muted);
  font-size: 11px;
}
.header-note { white-space: nowrap; }

.opening {
  display: grid;
  grid-template-columns: minmax(0, 1.32fr) minmax(310px, .68fr);
  gap: clamp(48px, 8vw, 112px);
  padding: 88px 0 86px;
  border-bottom: 1px solid var(--line);
}

.opening-copy { min-width: 0; }
.route-label {
  margin: 0 0 18px;
  color: var(--cyan);
  font-weight: 700;
  letter-spacing: .16em;
}

h1, h2, p { margin-top: 0; }
h1 {
  max-width: 650px;
  margin-bottom: 24px;
  font-size: 50px;
  line-height: 1.16;
  letter-spacing: -.025em;
  font-weight: 760;
}
.lead {
  max-width: 610px;
  margin-bottom: 30px;
  color: var(--muted);
  font-size: 17px;
  line-height: 1.75;
}
.opening-actions {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 18px;
}
.primary-action,
.text-action {
  min-height: 48px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 12px;
  text-decoration: none;
  font-weight: 700;
}
.primary-action {
  padding: 0 17px;
  color: #071013;
  background: var(--cyan);
}
.primary-action:hover { background: #8be2e7; }
.text-action {
  color: var(--muted);
  border-bottom: 1px solid var(--line-strong);
}
.text-action:hover { color: var(--text); border-bottom-color: var(--cyan); }

.boundary-panel {
  align-self: start;
  min-width: 0;
  padding: 18px 0 0;
  border-top: 2px solid var(--cyan);
}
.panel-heading {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 19px;
}
.panel-rule { width: 22px; height: 1px; background: var(--cyan); }
.panel-heading h2 { margin: 0; font-size: 15px; }
.boundary-list { margin: 0; }
.boundary-list > div {
  display: grid;
  grid-template-columns: 74px minmax(0, 1fr);
  gap: 18px;
  padding: 14px 0;
  border-bottom: 1px solid var(--line);
}
.boundary-list > div:first-child { border-top: 1px solid var(--line); }
dt { line-height: 1.45; }
dd {
  margin: 0;
  color: var(--text);
  font-size: 14px;
  line-height: 1.5;
}

.info-section {
  display: grid;
  grid-template-columns: 230px minmax(0, 1fr);
  gap: 42px;
  padding: 32px 0 34px;
  border-bottom: 1px solid var(--line);
}
.section-heading {
  display: flex;
  align-items: baseline;
  gap: 16px;
}
.section-index {
  color: var(--cyan);
  font-variant-numeric: tabular-nums;
}
.section-heading h2 {
  margin: 0;
  font-size: 19px;
  line-height: 1.35;
}
.section-content {
  max-width: 720px;
  color: var(--muted);
  font-size: 15px;
  line-height: 1.8;
}
.section-content p { margin: 0; }
.split-content {
  display: grid;
  grid-template-columns: minmax(0, 1.05fr) minmax(210px, .95fr);
  gap: 38px;
}
.quiet-copy { color: var(--quiet); }
.plain-list {
  display: grid;
  gap: 12px;
  margin: 0;
  padding: 0;
  list-style: none;
}
.plain-list li {
  display: grid;
  grid-template-columns: 18px minmax(0, 1fr);
  gap: 8px;
}
.plain-list li > span:first-child { color: var(--cyan); }

.site-footer {
  min-height: 84px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  color: var(--quiet);
  font-size: 11px;
}

@media (max-width: 760px) {
  .site-shell { width: min(100% - 28px, 560px); }
  .site-header { min-height: 66px; }
  .header-note { display: none; }
  .opening {
    display: block;
    padding: 54px 0 48px;
  }
  h1 { margin-bottom: 19px; font-size: 36px; line-height: 1.2; }
  .lead { margin-bottom: 24px; font-size: 15px; line-height: 1.7; }
  .opening-actions { gap: 14px; }
  .primary-action { width: 100%; }
  .text-action { min-height: 42px; }
  .boundary-panel { margin-top: 48px; padding-top: 14px; }
  .boundary-list > div { grid-template-columns: 70px minmax(0, 1fr); gap: 14px; padding: 12px 0; }
  .info-section {
    display: block;
    padding: 25px 0 27px;
  }
  .section-heading { margin-bottom: 15px; }
  .section-content { font-size: 14px; line-height: 1.75; }
  .split-content { display: block; }
  .split-content p + p { margin-top: 14px; }
  .site-footer { min-height: 76px; align-items: flex-start; flex-direction: column; gap: 6px; padding: 21px 0; }
}

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