:root {
  color-scheme: dark;
  --bg: #07101d;
  --bg-alt: #0b1628;
  --panel: rgba(12, 20, 36, 0.88);
  --panel-strong: rgba(15, 24, 44, 0.98);
  --line: rgba(161, 184, 255, 0.16);
  --text: #eef3ff;
  --muted: #a6b3cb;
  --accent: #6ba4ff;
  --accent-2: #79e0ff;
  --shadow: 0 24px 60px rgba(0, 0, 0, 0.34);
  --radius: 24px;
  --radius-lg: 32px;
  --container: 1200px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  min-width: 320px;
  color: var(--text);
  background:
    radial-gradient(circle at top left, rgba(107, 164, 255, 0.18), transparent 30%),
    radial-gradient(circle at top right, rgba(121, 224, 255, 0.08), transparent 24%),
    linear-gradient(180deg, #07101d 0%, #09111f 100%);
  font-family: "Noto Sans SC", "PingFang SC", "Microsoft YaHei", "Segoe UI", sans-serif;
  line-height: 1.7;
}

a { color: inherit; }
img {
  max-width: 100%;
  height: auto;
  display: block;
}
h1, h2, h3, p, span {
  word-break: normal;
  overflow-wrap: normal;
}
h1, h2, h3, p { margin-top: 0; }

.page { min-height: 100vh; }
.container {
  max-width: var(--container);
  margin-left: auto;
  margin-right: auto;
  padding-left: 24px;
  padding-right: 24px;
}

.topbar {
  position: sticky;
  top: 0;
  z-index: 30;
  background: rgba(5, 9, 18, 0.94);
  backdrop-filter: blur(18px);
  border-bottom: 1px solid var(--line);
}
.topbar__inner {
  min-height: 86px;
  display: grid;
  grid-template-columns: auto 1fr auto;
  gap: 18px;
  align-items: center;
}
.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
}
.brand__mark {
  width: 48px;
  height: 48px;
  object-fit: contain;
  flex: 0 0 auto;
}
.brand__text { display: flex; flex-direction: column; gap: 2px; }
.brand__name { font-size: 17px; font-weight: 800; line-height: 1.1; }
.brand__sub { font-size: 12px; color: var(--muted); line-height: 1.1; }

.nav, .topbar__actions, .hero-actions, .card-links, .hero-tags, .mini-rail {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}
.nav {
  justify-content: center;
  align-items: center;
  min-width: 0;
}
.nav a, .btn, .text-link {
  text-decoration: none;
  border: 1px solid transparent;
}
.nav a {
  min-height: 40px;
  display: inline-flex;
  align-items: center;
  padding: 0 14px;
  border-radius: 999px;
  color: var(--muted);
  background: rgba(255,255,255,0.04);
}
.nav a.is-active,
.nav a:hover {
  color: var(--text);
  border-color: rgba(255,255,255,0.12);
  background: rgba(107, 164, 255, 0.14);
}
.btn {
  min-height: 44px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0 18px;
  border-radius: 999px;
  font-weight: 700;
  transition: transform .18s ease, background .18s ease, border-color .18s ease;
}
.btn:hover { transform: translateY(-1px); }
.btn--primary {
  color: #07101d;
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
}
.btn--ghost {
  color: var(--text);
  background: rgba(255,255,255,0.05);
  border-color: var(--line);
}

section { padding: 28px 0; }
.hero { padding-top: 26px; }
.hero-grid {
  display: grid;
  grid-template-columns: minmax(600px, 1.04fr) minmax(320px, .96fr);
  gap: 28px;
  align-items: center;
}
.hero-copy, .section-head > div, .requirements-copy, .content-copy {
  min-width: 600px;
}
.eyebrow {
  margin-bottom: 10px;
  font-size: 12px;
  font-weight: 800;
  letter-spacing: .08em;
  text-transform: uppercase;
  color: var(--accent-2);
}
h1 {
  font-size: clamp(34px, 4vw, 56px);
  line-height: 1.14;
  letter-spacing: -0.02em;
}
h2 {
  font-size: clamp(24px, 2.6vw, 36px);
  line-height: 1.18;
}
h3 { font-size: 20px; line-height: 1.25; }
.lead, .section-lead, .content-copy p, .footer-brand p, .problem-item span, .route-step p, .version-item span, .note-card span {
  color: var(--muted);
}
.lead { font-size: 18px; max-width: 56ch; }

.hero-notes, .platform-grid, .route-grid, .mini-rail {
  display: grid;
  gap: 14px;
}
.hero-notes { grid-template-columns: repeat(3, minmax(0, 1fr)); margin-top: 22px; }
.note-card, .platform-card, .route-step, .problem-item, .rail-card, .footer-links > div, .table-wrap, .content-media, .hero-media {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}
.note-card, .platform-card, .route-step, .problem-item, .rail-card {
  padding: 16px;
}
.note-card strong, .platform-card h3, .route-step strong, .problem-item strong, .rail-card strong {
  display: block;
  margin-bottom: 6px;
}
.note-card span, .platform-card p, .route-step p, .problem-item span, .rail-card span {
  font-size: 15px;
}

.hero-media {
  position: relative;
  overflow: hidden;
  padding: 16px;
}
.hero-media img {
  width: 100%;
  max-height: 520px;
  object-fit: cover;
  border-radius: 24px;
}
.hero-overlay {
  position: absolute;
  left: 26px;
  right: 26px;
  bottom: 24px;
  padding: 16px 18px;
  border-radius: 20px;
  background: linear-gradient(180deg, rgba(6, 10, 22, 0.02), rgba(6, 10, 22, 0.74));
}
.hero-tags .tag {
  display: inline-flex;
  align-items: center;
  padding: 7px 12px;
  border-radius: 999px;
  background: rgba(255,255,255,0.08);
  color: var(--text);
  border: 1px solid rgba(255,255,255,0.08);
}

.section-head {
  display: flex;
  justify-content: space-between;
  gap: 18px;
  align-items: flex-end;
  margin-bottom: 18px;
}
.section-head > div { flex: 0 1 auto; }
.section-lead { max-width: 40ch; margin: 0; }

.platform-grid {
  grid-template-columns: repeat(4, minmax(0, 1fr));
}
.platform-card {
  min-height: 220px;
  display: flex;
  flex-direction: column;
  gap: 12px;
}
.platform-kicker {
  font-size: 12px;
  font-weight: 800;
  letter-spacing: .06em;
  color: var(--accent-2);
}
.text-link {
  color: var(--text);
  display: inline-flex;
  gap: 6px;
  align-items: center;
}
.text-link::after {
  content: "→";
  color: var(--accent-2);
}
.card-links {
  margin-top: auto;
}

.content-split {
  display: grid;
  grid-template-columns: minmax(0, .96fr) minmax(600px, 1.04fr);
  gap: 28px;
  align-items: center;
}
.content-split--reverse {
  grid-template-columns: minmax(600px, 1.04fr) minmax(0, .96fr);
}
.content-media {
  overflow: hidden;
  padding: 16px;
}
.hero-media img {
  width: 100%;
  max-height: 520px;
  object-fit: cover;
  border-radius: 24px;
}
.content-media img {
  width: 100%;
  max-height: 420px;
  object-fit: cover;
  border-radius: 20px;
}
.version-list, .problem-list {
  display: grid;
  gap: 12px;
  margin: 22px 0;
}
.version-item, .problem-item {
  padding: 16px 18px;
  border-radius: 18px;
  background: rgba(255,255,255,0.03);
  border: 1px solid var(--line);
}

.route-grid {
  grid-template-columns: repeat(4, minmax(0, 1fr));
}
.route-step {
  position: relative;
  overflow: hidden;
}
.route-num {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 38px;
  height: 38px;
  margin-bottom: 14px;
  border-radius: 12px;
  color: #09111f;
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  font-weight: 800;
}

.requirements-block {
  display: grid;
  grid-template-columns: minmax(320px, .86fr) minmax(0, 1.14fr);
  gap: 24px;
  align-items: start;
}
.table-wrap {
  overflow: hidden;
}
table {
  width: 100%;
  border-collapse: collapse;
}
th, td {
  padding: 16px 18px;
  text-align: left;
  border-bottom: 1px solid rgba(255,255,255,0.08);
  vertical-align: top;
}
th {
  font-size: 14px;
  color: var(--muted);
  background: rgba(255,255,255,0.03);
}

.footer {
  margin-top: 28px;
  border-top: 1px solid var(--line);
  background: rgba(7, 13, 24, 0.96);
}
.footer-grid {
  display: grid;
  grid-template-columns: minmax(0, .9fr) minmax(0, 1.1fr);
  gap: 24px;
  padding: 26px 24px 30px;
}
.footer-brand {
  padding-right: 14px;
}
.footer-links {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 12px;
  align-items: start;
}
.footer-links > div {
  padding: 18px;
  min-width: 0;
}
.footer-links strong {
  display: block;
  margin-bottom: 12px;
}
.footer-links a {
  display: block;
  color: var(--muted);
  text-decoration: none;
  margin-top: 8px;
}
.footer-links a:hover { color: var(--text); }

@media (max-width: 1100px) {
  .topbar__inner,
  .hero-grid,
  .content-split,
  .requirements-block,
  .footer-grid {
    grid-template-columns: 1fr;
  }

  .platform-grid,
  .route-grid,
  .hero-notes {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .hero-copy,
  .section-head > div,
  .requirements-copy,
  .content-copy {
    min-width: 0;
  }

  .nav {
    justify-content: flex-start;
  }
}

@media (max-width: 760px) {
  .container {
    padding-left: 20px;
    padding-right: 20px;
  }

  .platform-grid,
  .route-grid,
  .hero-notes,
  .footer-links {
    grid-template-columns: 1fr;
  }

  .section-head {
    flex-direction: column;
    align-items: flex-start;
  }

  .topbar__inner {
    min-height: auto;
    padding: 14px 0;
  }

  .nav a,
  .btn {
    width: 100%;
  }

  .hero-actions, .card-links {
    width: 100%;
  }
}