:root {
  --bg: #101820;
  --bg-soft: #17242d;
  --panel: #f5f0e6;
  --panel-2: #fffaf1;
  --ink: #19222a;
  --muted: #64727d;
  --line: rgba(25, 34, 42, 0.14);
  --line-dark: rgba(255, 250, 241, 0.16);
  --accent: #d64f37;
  --accent-2: #19a0a8;
  --accent-3: #f0b24a;
  --dark-ink: #f7f3ea;
  --dark-muted: #b9c6cc;
  --shadow: 0 16px 42px rgba(0, 0, 0, 0.2);
  --shadow-lift: 0 22px 58px rgba(0, 0, 0, 0.28);
  --ease: cubic-bezier(0.2, 0.75, 0.25, 1);
  --container: 980px;
  --radius: 6px;
  --font-body: "Noto Sans SC", "Microsoft YaHei", "PingFang SC", Arial, sans-serif;
  --font-title: "Microsoft YaHei", "PingFang SC", Arial, sans-serif;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--ink);
  background:
    linear-gradient(90deg, rgba(255, 255, 255, 0.04) 1px, transparent 1px),
    linear-gradient(180deg, rgba(255, 255, 255, 0.035) 1px, transparent 1px),
    var(--bg);
  background-size: 32px 32px;
  font-family: var(--font-body);
  font-size: 14px;
  line-height: 1.62;
}

body::before {
  position: fixed;
  inset: 0;
  z-index: -1;
  pointer-events: none;
  content: "";
  background:
    linear-gradient(130deg, rgba(25, 160, 168, 0.18), transparent 36%),
    linear-gradient(310deg, rgba(214, 79, 55, 0.18), transparent 34%);
}

img {
  display: block;
  max-width: 100%;
  height: auto;
}

a {
  color: inherit;
  text-decoration: none;
}

button {
  font: inherit;
}

strong {
  font-weight: 800;
}

::selection {
  color: var(--bg);
  background: var(--accent-3);
}

.skip-link {
  position: fixed;
  top: 12px;
  left: 12px;
  z-index: 20;
  padding: 9px 12px;
  color: var(--bg);
  background: var(--accent-3);
  border-radius: 999px;
  transform: translateY(-140%);
  transition: transform 0.18s ease;
}

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

.shell {
  display: grid;
  grid-template-columns: 196px minmax(0, 1fr);
  min-height: 100vh;
}

.rail {
  position: sticky;
  top: 0;
  display: flex;
  flex-direction: column;
  gap: 18px;
  align-self: start;
  height: 100vh;
  padding: 22px 16px;
  color: var(--dark-ink);
  background: rgba(13, 22, 29, 0.92);
  border-right: 1px solid var(--line-dark);
  backdrop-filter: blur(16px);
}

.rail-brand {
  display: grid;
  gap: 8px;
  justify-items: start;
  font-family: var(--font-title);
  font-size: 1rem;
  font-weight: 900;
}

.rail-brand img {
  width: 46px;
  height: 46px;
  object-fit: cover;
  border: 2px solid rgba(255, 250, 241, 0.35);
  border-radius: 6px;
}

.rail-nav {
  display: grid;
  gap: 5px;
}

.rail-nav a {
  position: relative;
  overflow: hidden;
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 34px;
  padding: 6px 10px;
  color: var(--dark-muted);
  border: 1px solid transparent;
  border-radius: var(--radius);
  transition: color 0.22s var(--ease), background 0.22s var(--ease), border-color 0.22s var(--ease), transform 0.22s var(--ease);
}

.rail-nav a::before {
  position: absolute;
  inset: 0 auto 0 0;
  width: 3px;
  content: "";
  background: var(--accent-3);
  opacity: 0;
  transform: scaleY(0.35);
  transform-origin: center;
  transition: opacity 0.22s var(--ease), transform 0.22s var(--ease);
}

.rail-nav a::after {
  width: 8px;
  height: 8px;
  content: "";
  border-top: 2px solid currentColor;
  border-right: 2px solid currentColor;
  opacity: 0.45;
  transform: rotate(45deg);
}

.rail-nav a:hover,
.rail-nav a:focus-visible,
.rail-nav a.is-active {
  color: var(--dark-ink);
  background: rgba(255, 250, 241, 0.1);
  border-color: var(--line-dark);
  transform: translateX(3px);
  outline: none;
}

.rail-nav a:hover::before,
.rail-nav a:focus-visible::before,
.rail-nav a.is-active::before {
  opacity: 1;
  transform: scaleY(1);
}

.rail-download {
  position: relative;
  display: block;
  overflow: hidden;
  margin-top: auto;
  padding: 10px 12px;
  color: #111a20;
  background: var(--accent-3);
  border-radius: var(--radius);
  font-weight: 900;
  text-align: center;
  box-shadow: 0 14px 36px rgba(240, 178, 74, 0.2);
  transition: transform 0.22s var(--ease), box-shadow 0.22s var(--ease), filter 0.22s var(--ease);
}

.page {
  min-width: 0;
  padding: 18px clamp(14px, 3vw, 38px) 28px;
}

.masthead,
.overview-grid,
.route-panel,
.systems,
.manual,
.gallery,
.updates,
.faq,
.footer {
  width: min(var(--container), 100%);
  margin: 0 auto;
}

.masthead {
  display: grid;
  grid-template-columns: minmax(0, 0.9fr) minmax(260px, 0.65fr);
  gap: clamp(18px, 3vw, 38px);
  align-items: stretch;
  min-height: 0;
  padding: clamp(30px, 4.2vw, 54px) 0 clamp(26px, 3.6vw, 44px);
}

.masthead-copy {
  display: flex;
  flex-direction: column;
  justify-content: center;
  color: var(--dark-ink);
}

.label {
  margin: 0 0 8px;
  color: var(--accent-3);
  font-size: 0.7rem;
  font-weight: 900;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

h1,
h2,
h3,
p {
  margin-top: 0;
}

h1,
h2,
h3 {
  font-family: var(--font-title);
  line-height: 1.18;
  letter-spacing: 0;
}

h1 {
  margin-bottom: 14px;
  color: var(--accent-3);
  font-size: clamp(2.15rem, 4.8vw, 4.25rem);
  font-weight: 900;
}

h2 {
  margin-bottom: 12px;
  color: var(--accent);
  font-size: clamp(1.25rem, 2.35vw, 1.95rem);
  font-weight: 900;
}

h2 {
  position: relative;
}

.section-title h2::after,
.overview-card h2::after,
.systems-copy h2::after {
  display: block;
  width: 42px;
  height: 3px;
  margin-top: 10px;
  content: "";
  background: linear-gradient(90deg, var(--accent), var(--accent-3));
  border-radius: 999px;
  transform-origin: left;
  transition: width 0.26s var(--ease);
}

.route-panel:hover .section-title h2::after,
.manual:hover .section-title h2::after,
.gallery:hover .section-title h2::after,
.updates:hover .section-title h2::after,
.faq:hover .section-title h2::after,
.overview-card:hover h2::after,
.systems:hover .systems-copy h2::after {
  width: 72px;
}

.masthead h1 {
  color: var(--accent-3);
  text-shadow: 0 8px 28px rgba(240, 178, 74, 0.16);
}

.overview-card h2,
.route-panel h2,
.systems h2,
.manual h2,
.gallery h2,
.updates h2,
.faq h2 {
  color: var(--accent);
}

h3 {
  margin-bottom: 6px;
  font-size: 1.02rem;
  font-weight: 900;
}

.masthead-copy p:not(.label) {
  max-width: 560px;
  color: var(--dark-muted);
  font-size: clamp(0.92rem, 1.1vw, 1rem);
}

.actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 14px;
}

.button {
  position: relative;
  overflow: hidden;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 38px;
  padding: 8px 14px;
  border: 1px solid transparent;
  border-radius: var(--radius);
  font-weight: 900;
  transition: transform 0.22s var(--ease), box-shadow 0.22s var(--ease), background 0.22s var(--ease), border-color 0.22s var(--ease), color 0.22s var(--ease);
}

.button::after,
.rail-download::after {
  position: absolute;
  inset: 0;
  pointer-events: none;
  content: "";
  background: linear-gradient(110deg, transparent 0%, rgba(255, 255, 255, 0.28) 45%, transparent 70%);
  opacity: 0;
  transform: translateX(-120%);
  transition: opacity 0.22s var(--ease), transform 0.55s var(--ease);
}

.button:hover,
.button:focus-visible,
.rail-download:hover,
.rail-download:focus-visible,
.back-top:hover,
.back-top:focus-visible {
  transform: translateY(-3px);
  outline: none;
}

.button:hover::after,
.button:focus-visible::after,
.rail-download:hover::after,
.rail-download:focus-visible::after {
  opacity: 1;
  transform: translateX(120%);
}

.button.primary {
  color: #111a20;
  background: var(--accent-3);
  box-shadow: 0 16px 42px rgba(240, 178, 74, 0.2);
}

.button.primary:hover,
.button.primary:focus-visible,
.rail-download:hover,
.rail-download:focus-visible {
  filter: saturate(1.08) brightness(1.04);
  box-shadow: 0 18px 44px rgba(240, 178, 74, 0.3);
}

.button.secondary {
  color: var(--dark-ink);
  background: rgba(255, 250, 241, 0.08);
  border-color: var(--line-dark);
}

.button.secondary:hover,
.button.secondary:focus-visible {
  color: var(--accent-3);
  background: rgba(255, 250, 241, 0.13);
  border-color: rgba(240, 178, 74, 0.38);
}

.cover-board {
  position: relative;
  align-self: center;
  margin: 0;
  color: var(--dark-ink);
}

.cover-board img {
  width: 100%;
  aspect-ratio: 616 / 353;
  object-fit: cover;
  border: 1px solid var(--line-dark);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  transition: transform 0.35s var(--ease), filter 0.35s var(--ease), box-shadow 0.35s var(--ease);
}

.cover-board:hover img,
.cover-board:focus-within img {
  filter: saturate(1.08) contrast(1.04);
  transform: translateY(-4px) scale(1.01);
  box-shadow: var(--shadow-lift);
}

.cover-board figcaption {
  position: absolute;
  right: 12px;
  bottom: 12px;
  min-width: min(220px, calc(100% - 24px));
  padding: 10px 12px;
  background: rgba(13, 22, 29, 0.86);
  border: 1px solid var(--line-dark);
  border-radius: var(--radius);
  backdrop-filter: blur(14px);
}

.cover-board span {
  display: block;
  color: var(--accent-3);
  font-size: 0.75rem;
  font-weight: 900;
}

.cover-board strong {
  display: block;
  margin-top: 2px;
  font-size: 0.92rem;
}

.nav-toggle {
  display: none;
}

.overview-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 12px;
  margin-bottom: 20px;
}

.overview-card,
.route-panel,
.systems,
.manual,
.gallery,
.updates,
.faq,
.footer {
  position: relative;
  overflow: hidden;
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  transition: transform 0.25s var(--ease), border-color 0.25s var(--ease), box-shadow 0.25s var(--ease), background 0.25s var(--ease);
}

.overview-card::before,
.route-panel::before,
.systems::before,
.manual::before,
.gallery::before,
.updates::before,
.faq::before {
  position: absolute;
  inset: 0;
  pointer-events: none;
  content: "";
  background:
    linear-gradient(135deg, rgba(240, 178, 74, 0.16), transparent 28%),
    linear-gradient(315deg, rgba(25, 160, 168, 0.1), transparent 30%);
  opacity: 0;
  transition: opacity 0.25s var(--ease);
}

.overview-card:hover,
.route-panel:hover,
.systems:hover,
.manual:hover,
.gallery:hover,
.updates:hover,
.faq:hover {
  border-color: rgba(214, 79, 55, 0.28);
  box-shadow: var(--shadow-lift);
  transform: translateY(-3px);
}

.overview-card:hover::before,
.route-panel:hover::before,
.systems:hover::before,
.manual:hover::before,
.gallery:hover::before,
.updates:hover::before,
.faq:hover::before {
  opacity: 1;
}

.overview-card {
  min-height: 188px;
  padding: 18px;
}

.card-mark {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 24px;
  margin-bottom: 20px;
  color: var(--bg);
  background: var(--accent-3);
  border-radius: 4px;
  font-size: 0.72rem;
  font-weight: 900;
  transition: transform 0.24s var(--ease), box-shadow 0.24s var(--ease);
}

.overview-card:hover .card-mark {
  box-shadow: 0 10px 22px rgba(240, 178, 74, 0.26);
  transform: translateY(-2px) rotate(-2deg);
}

.overview-card p,
.section-title p,
.systems-copy p,
.manual-page p,
.manual-page li,
.timeline p,
.faq p,
.footer p,
.route-list p {
  color: var(--muted);
}

.route-panel,
.manual,
.gallery,
.updates,
.faq {
  margin-top: 20px;
  padding: clamp(18px, 3vw, 32px);
}

.section-title {
  display: grid;
  max-width: 650px;
  margin-bottom: 18px;
}

.route-list {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 1px;
  margin: 0;
  padding: 0;
  list-style: none;
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: var(--radius);
}

.route-list li {
  position: relative;
  padding: 16px;
  background: var(--panel-2);
  transition: background 0.22s var(--ease), transform 0.22s var(--ease);
}

.route-list li:hover {
  z-index: 1;
  background: #fffdf7;
  transform: translateY(-2px);
}

.route-list span,
.timeline time {
  display: inline-flex;
  margin-bottom: 8px;
  color: var(--accent);
  font-size: 0.68rem;
  font-weight: 900;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.systems {
  display: grid;
  grid-template-columns: minmax(260px, 0.78fr) minmax(0, 1fr);
  gap: clamp(14px, 3vw, 30px);
  align-items: center;
  margin-top: 20px;
  padding: clamp(14px, 2.4vw, 24px);
}

.systems-media img {
  width: 100%;
  aspect-ratio: 600 / 342;
  object-fit: cover;
  border-radius: var(--radius);
  transition: transform 0.32s var(--ease), filter 0.32s var(--ease);
}

.systems:hover .systems-media img {
  filter: saturate(1.06) contrast(1.04);
  transform: scale(1.015);
}

.system-stack {
  display: grid;
  gap: 8px;
}

.system-stack article {
  padding: 12px 0 10px;
  border-top: 1px solid var(--line);
}

.system-stack article:first-child {
  border-top: 0;
}

.manual-layout {
  display: grid;
  grid-template-columns: 150px minmax(0, 1fr);
  gap: 16px;
  align-items: start;
}

.manual-tabs {
  position: sticky;
  top: 18px;
  display: grid;
  gap: 6px;
}

.manual-tabs a {
  padding: 8px 10px;
  color: var(--muted);
  background: var(--panel-2);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  font-weight: 800;
  transition: transform 0.2s var(--ease), color 0.2s var(--ease), border-color 0.2s var(--ease), background 0.2s var(--ease);
}

.manual-tabs a:hover,
.manual-tabs a:focus-visible,
.manual-tabs a.is-active {
  color: var(--ink);
  background: #fffdf7;
  border-color: rgba(214, 79, 55, 0.42);
  transform: translateX(3px);
  outline: none;
}

.manual-pages {
  display: grid;
  gap: 10px;
}

.manual-page {
  position: relative;
  padding: clamp(14px, 2.2vw, 20px);
  background: var(--panel-2);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  transition: transform 0.22s var(--ease), border-color 0.22s var(--ease), box-shadow 0.22s var(--ease), background 0.22s var(--ease);
}

.manual-page:hover {
  background: #fffdf7;
  border-color: rgba(25, 160, 168, 0.34);
  box-shadow: 0 12px 30px rgba(16, 24, 32, 0.1);
  transform: translateX(3px);
}

.manual-page ul {
  display: grid;
  gap: 5px;
  margin: 10px 0 0;
  padding-left: 18px;
}

.gallery-strip {
  display: grid;
  grid-template-columns: 1.15fr 1fr 0.85fr;
  gap: 10px;
}

.gallery-strip figure {
  position: relative;
  min-height: 190px;
  margin: 0;
  overflow: hidden;
  background: #111a20;
  border-radius: var(--radius);
  box-shadow: 0 12px 28px rgba(16, 24, 32, 0.14);
  transition: transform 0.28s var(--ease), box-shadow 0.28s var(--ease);
}

.gallery-strip img {
  width: 100%;
  height: 100%;
  min-height: 190px;
  object-fit: cover;
  transition: transform 0.28s ease;
}

.gallery-strip figure:hover {
  box-shadow: 0 18px 42px rgba(16, 24, 32, 0.25);
  transform: translateY(-4px);
}

.gallery-strip figure:hover img {
  transform: scale(1.06);
}

.gallery-strip figcaption {
  position: absolute;
  left: 10px;
  bottom: 10px;
  padding: 5px 8px;
  color: var(--dark-ink);
  background: rgba(13, 22, 29, 0.78);
  border: 1px solid var(--line-dark);
  border-radius: 5px;
  font-size: 0.78rem;
  font-weight: 800;
}

.timeline {
  display: grid;
  gap: 9px;
}

.timeline article {
  position: relative;
  padding: 14px 14px 14px 24px;
  background: var(--panel-2);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  transition: transform 0.22s var(--ease), border-color 0.22s var(--ease), background 0.22s var(--ease), box-shadow 0.22s var(--ease);
}

.timeline article:hover {
  background: #fffdf7;
  border-color: rgba(214, 79, 55, 0.3);
  box-shadow: 0 12px 30px rgba(16, 24, 32, 0.1);
  transform: translateX(4px);
}

.timeline article::before {
  position: absolute;
  top: 19px;
  left: 10px;
  width: 6px;
  height: 6px;
  content: "";
  background: var(--accent-2);
  border-radius: 999px;
}

.faq-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 9px;
}

.faq details {
  padding: 12px 14px;
  background: var(--panel-2);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  transition: background 0.22s var(--ease), border-color 0.22s var(--ease), box-shadow 0.22s var(--ease), transform 0.22s var(--ease);
}

.faq details:hover,
.faq details[open] {
  background: #fffdf7;
  border-color: rgba(240, 178, 74, 0.42);
  box-shadow: 0 10px 28px rgba(16, 24, 32, 0.09);
  transform: translateY(-2px);
}

.faq summary {
  cursor: pointer;
  font-weight: 900;
  transition: color 0.2s var(--ease);
}

.faq details:hover summary,
.faq details[open] summary {
  color: var(--accent);
}

.faq summary::marker {
  color: var(--accent);
}

.faq p {
  margin: 8px 0 0;
}

.footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 14px;
  margin-top: 20px;
  padding: 18px;
  color: var(--dark-ink);
  background: rgba(13, 22, 29, 0.9);
  border-color: var(--line-dark);
}

.footer strong {
  display: block;
  margin-bottom: 6px;
}

.footer p {
  margin: 0;
  color: var(--dark-muted);
}

.back-top {
  flex: 0 0 auto;
  min-height: 36px;
  padding: 7px 12px;
  color: var(--bg);
  cursor: pointer;
  background: var(--accent-3);
  border: 0;
  border-radius: var(--radius);
  font-weight: 900;
  transition: transform 0.22s var(--ease), box-shadow 0.22s var(--ease), filter 0.22s var(--ease);
}

.back-top:hover,
.back-top:focus-visible {
  filter: saturate(1.08) brightness(1.04);
  box-shadow: 0 14px 34px rgba(240, 178, 74, 0.24);
}

.reveal {
  opacity: 0;
  transform: translateY(16px);
  transition: opacity 0.42s ease, transform 0.42s ease;
}

.overview-card.reveal,
.manual-page.reveal,
.gallery-strip figure.reveal,
.timeline article.reveal,
.faq details.reveal {
  transition:
    opacity 0.42s ease,
    transform 0.42s ease,
    border-color 0.25s var(--ease),
    box-shadow 0.25s var(--ease),
    background 0.25s var(--ease),
    filter 0.25s var(--ease);
}

.reveal.is-visible,
.js-ready .reveal:first-child {
  opacity: 1;
  transform: translateY(0);
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    scroll-behavior: auto !important;
    transition-duration: 0.01ms !important;
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
  }

  .reveal {
    opacity: 1;
    transform: none;
  }
}

@media (max-width: 1120px) {
  .shell {
    grid-template-columns: 1fr;
  }

  .rail {
    position: fixed;
    inset: 0 auto 0 0;
    z-index: 15;
    width: min(300px, 84vw);
    padding-top: 76px;
    transform: translateX(-102%);
    transition: transform 0.22s ease;
  }

  .rail.is-open {
    transform: translateX(0);
  }

  .page {
    padding-top: 18px;
  }

  .nav-toggle {
    position: fixed;
    top: 14px;
    left: 14px;
    z-index: 18;
    display: grid;
    gap: 5px;
    align-content: center;
    width: 44px;
    height: 44px;
    padding: 10px;
    cursor: pointer;
    background: rgba(13, 22, 29, 0.9);
    border: 1px solid var(--line-dark);
    border-radius: var(--radius);
  }

  .nav-toggle span {
    display: block;
    height: 2px;
    background: var(--dark-ink);
    border-radius: 999px;
    transition: opacity 0.2s var(--ease), transform 0.2s var(--ease), background 0.2s var(--ease);
    transform-origin: center;
  }

  .nav-toggle.is-open {
    background: var(--accent-3);
    border-color: rgba(240, 178, 74, 0.7);
  }

  .nav-toggle.is-open span {
    background: var(--bg);
  }

  .nav-toggle.is-open span:nth-child(1) {
    transform: translateY(7px) rotate(45deg);
  }

  .nav-toggle.is-open span:nth-child(2) {
    opacity: 0;
    transform: scaleX(0);
  }

  .nav-toggle.is-open span:nth-child(3) {
    transform: translateY(-7px) rotate(-45deg);
  }

  .masthead {
    padding-top: 62px;
  }
}

@media (max-width: 860px) {
  body {
    font-size: 15px;
  }

  .masthead {
    grid-template-columns: 1fr;
    min-height: auto;
  }

  .overview-grid,
  .route-list,
  .systems,
  .manual-layout,
  .gallery-strip,
  .faq-grid {
    grid-template-columns: 1fr;
  }

  .manual-tabs {
    position: static;
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

@media (max-width: 540px) {
  .page {
    padding-inline: 14px;
  }

  h1 {
    font-size: 2.45rem;
  }

  .actions,
  .footer {
    align-items: stretch;
    flex-direction: column;
  }

  .button,
  .back-top {
    width: 100%;
  }

  .overview-card,
  .route-panel,
  .manual,
  .gallery,
  .updates,
  .faq,
  .footer {
    padding: 20px;
  }

  .manual-tabs {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}