:root {
  --bg: #f3f5f7;
  --surface: rgba(255, 255, 255, 0.68);
  --surface-strong: rgba(255, 255, 255, 0.9);
  --text: #12161a;
  --muted: #5b6470;
  --line: rgba(18, 22, 26, 0.12);
  --accent: #2b5cff;
  --accent-soft: #90afff;
  --radius-xl: 28px;
  --radius-lg: 20px;
  --radius-md: 14px;
  --shadow-lg: 0 30px 80px rgba(20, 26, 35, 0.15);
  --shadow-md: 0 16px 42px rgba(20, 26, 35, 0.12);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  min-height: 100vh;
  color: var(--text);
  background: linear-gradient(170deg, #f8fafc 0%, #edf2f8 48%, #e7edf6 100%);
  font-family: "SF Pro Display", "Avenir Next", "PingFang SC", "Hiragino Sans GB",
    "Noto Sans CJK SC", sans-serif;
  line-height: 1.55;
}

.ambient {
  position: fixed;
  border-radius: 999px;
  filter: blur(70px);
  pointer-events: none;
  z-index: 0;
  opacity: 0.45;
}

.ambient-a {
  width: 42vw;
  height: 42vw;
  top: -12vw;
  left: -6vw;
  background: radial-gradient(circle, #8db1ff 0%, #d7e3ff 55%, transparent 70%);
}

.ambient-b {
  width: 38vw;
  height: 38vw;
  bottom: -10vw;
  right: -8vw;
  background: radial-gradient(circle, #9bd5d2 0%, #d7f0ef 50%, transparent 72%);
}

.topbar,
main,
.footer,
.lightbox {
  position: relative;
  z-index: 1;
}

.topbar {
  width: min(1180px, calc(100% - 2.2rem));
  margin: 1.1rem auto 0;
  padding: 0.7rem 1rem 0.7rem 0.9rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-radius: 999px;
  border: 1px solid rgba(255, 255, 255, 0.5);
  backdrop-filter: blur(16px);
  background: rgba(247, 251, 255, 0.55);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 0.7rem;
  color: var(--text);
  text-decoration: none;
  font-weight: 600;
}

.brand-mark {
  width: 2.1rem;
  height: 2.1rem;
  display: grid;
  place-items: center;
  border-radius: 999px;
  color: #fff;
  font-size: 0.88rem;
  background: linear-gradient(135deg, #111927, #2f4366);
}

.brand-text {
  letter-spacing: 0.02em;
  font-size: 0.95rem;
}

.nav {
  display: inline-flex;
  gap: 1rem;
}

.nav a {
  color: var(--muted);
  text-decoration: none;
  font-size: 0.9rem;
  transition: color 0.25s ease;
}

.nav a:hover {
  color: var(--text);
}

main {
  width: min(1180px, calc(100% - 2.2rem));
  margin: 1.25rem auto 0;
}

.hero {
  display: grid;
  gap: 1.35rem;
  grid-template-columns: 1.08fr 0.92fr;
}

.hero-copy,
.hero-media,
.section,
.about {
  border: 1px solid rgba(255, 255, 255, 0.56);
  background: var(--surface);
  border-radius: var(--radius-xl);
  backdrop-filter: blur(14px);
  box-shadow: var(--shadow-md);
}

.hero-copy {
  padding: clamp(1.5rem, 3.3vw, 2.8rem);
}

.eyebrow {
  margin: 0;
  font-size: 0.76rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: #4a5870;
  font-weight: 600;
}

h1,
h2 {
  margin: 0;
  font-family: "Iowan Old Style", "Songti SC", "STSong", serif;
  letter-spacing: -0.01em;
  line-height: 1.12;
}

h1 {
  margin-top: 0.7rem;
  font-size: clamp(2.1rem, 4.6vw, 4.1rem);
  max-width: 16ch;
}

.hero-desc {
  color: var(--muted);
  margin: 1rem 0 1.2rem;
  max-width: 50ch;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.8rem;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.68rem 1.15rem;
  border-radius: 999px;
  text-decoration: none;
  font-size: 0.9rem;
  font-weight: 600;
  transition: transform 0.2s ease, box-shadow 0.2s ease, background 0.2s ease;
}

.btn:hover {
  transform: translateY(-1px);
}

.btn-solid {
  color: #fff;
  background: linear-gradient(135deg, #1c2b4f, #324d88);
  box-shadow: 0 10px 25px rgba(27, 43, 79, 0.28);
}

.btn-ghost {
  color: var(--text);
  background: rgba(255, 255, 255, 0.74);
  border: 1px solid rgba(18, 22, 26, 0.08);
}

.stat-row {
  margin-top: 1.35rem;
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 0.8rem;
}

.stat {
  padding: 0.78rem 0.86rem;
  border-radius: var(--radius-md);
  border: 1px solid rgba(18, 22, 26, 0.08);
  background: rgba(255, 255, 255, 0.62);
}

.stat p {
  margin: 0;
  font-size: 1.25rem;
  font-weight: 700;
}

.stat span {
  font-size: 0.78rem;
  color: var(--muted);
}

.hero-media {
  overflow: hidden;
}

.hero-media img {
  display: block;
  width: 100%;
  height: 100%;
  min-height: 420px;
  object-fit: cover;
}

.section {
  margin-top: 1.35rem;
  padding: clamp(1.2rem, 2.8vw, 2.2rem);
}

.section-head p {
  margin: 0.8rem 0 0;
  color: var(--muted);
}

h2 {
  margin-top: 0.58rem;
  font-size: clamp(1.55rem, 3.2vw, 2.55rem);
}

.route-grid {
  margin-top: 1.2rem;
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 0.9rem;
}

.route-card {
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  overflow: hidden;
  background: var(--surface-strong);
  transition: transform 0.28s ease, box-shadow 0.28s ease;
}

.route-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
}

.route-card img {
  width: 100%;
  height: 170px;
  object-fit: cover;
  display: block;
}

.route-body {
  padding: 0.9rem;
}

.route-name {
  margin: 0;
  font-size: 1.08rem;
}

.route-meta {
  margin: 0.38rem 0;
  color: var(--muted);
  font-size: 0.85rem;
}

.route-highlight {
  margin: 0.1rem 0 0.8rem;
  font-size: 0.88rem;
}

.route-action {
  border: 1px solid rgba(27, 42, 74, 0.2);
  border-radius: 999px;
  color: #1b2a4a;
  background: rgba(245, 249, 255, 0.8);
  padding: 0.45rem 0.86rem;
  font-size: 0.78rem;
  font-weight: 600;
  cursor: pointer;
}

.filter-row {
  margin-top: 1.25rem;
  display: flex;
  gap: 0.65rem;
  flex-wrap: wrap;
}

.filter-btn {
  border: 1px solid rgba(18, 22, 26, 0.14);
  border-radius: 999px;
  padding: 0.45rem 0.9rem;
  font-size: 0.8rem;
  background: rgba(255, 255, 255, 0.72);
  color: var(--text);
  cursor: pointer;
  transition: background 0.2s ease, color 0.2s ease, border 0.2s ease;
}

.filter-btn.active {
  background: linear-gradient(135deg, #1b2a4a, #324d88);
  color: #fff;
  border-color: transparent;
}

.gallery-grid {
  margin-top: 1rem;
  columns: 4 240px;
  column-gap: 0.9rem;
}

.photo-card {
  margin: 0 0 0.9rem;
  break-inside: avoid;
  border-radius: var(--radius-md);
  overflow: hidden;
  background: var(--surface-strong);
  border: 1px solid var(--line);
  box-shadow: 0 8px 20px rgba(16, 22, 28, 0.1);
  cursor: zoom-in;
}

.photo-card img {
  width: 100%;
  display: block;
}

.photo-caption {
  padding: 0.55rem 0.7rem 0.65rem;
}

.photo-caption p {
  margin: 0;
  font-size: 0.76rem;
  color: #3f4b5d;
}

.about {
  margin-top: 1.35rem;
  padding: clamp(1.4rem, 2.9vw, 2.4rem);
}

.about p {
  margin: 0.9rem 0 0;
  color: var(--muted);
  max-width: 66ch;
}

.footer {
  padding: 2rem 1rem 2.4rem;
  text-align: center;
  color: #566276;
  font-size: 0.85rem;
}

.lightbox {
  position: fixed;
  inset: 0;
  display: none;
  background: rgba(8, 12, 18, 0.87);
  backdrop-filter: blur(4px);
  align-items: center;
  justify-content: center;
}

.lightbox.open {
  display: flex;
}

.lightbox img {
  width: min(92vw, 1180px);
  height: min(83vh, 880px);
  object-fit: contain;
}

#lightbox-caption {
  position: absolute;
  left: 50%;
  bottom: 2rem;
  transform: translateX(-50%);
  margin: 0;
  color: #ecf2fc;
  font-size: 0.86rem;
}

.lightbox-close,
.lightbox-nav {
  position: absolute;
  border: 1px solid rgba(255, 255, 255, 0.28);
  background: rgba(16, 20, 26, 0.45);
  color: #fff;
  border-radius: 999px;
  display: grid;
  place-items: center;
  cursor: pointer;
}

.lightbox-close {
  top: 1.3rem;
  right: 1.5rem;
  width: 2.5rem;
  height: 2.5rem;
  font-size: 1.3rem;
}

.lightbox-nav {
  top: 50%;
  transform: translateY(-50%);
  width: 2.8rem;
  height: 2.8rem;
  font-size: 1.6rem;
}

.lightbox-nav.prev {
  left: 1.5rem;
}

.lightbox-nav.next {
  right: 1.5rem;
}

.reveal {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.7s ease, transform 0.7s ease;
}

.reveal.visible {
  opacity: 1;
  transform: translateY(0);
}

@media (max-width: 1060px) {
  .hero {
    grid-template-columns: 1fr;
  }

  .hero-media img {
    min-height: 340px;
  }

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

@media (max-width: 760px) {
  .topbar {
    margin-top: 0.8rem;
  }

  .brand-text {
    display: none;
  }

  .nav {
    gap: 0.6rem;
  }

  .nav a {
    font-size: 0.79rem;
  }

  .stat-row {
    grid-template-columns: 1fr;
  }

  .route-grid {
    grid-template-columns: 1fr;
  }

  .gallery-grid {
    columns: 2 160px;
  }

  .lightbox-nav {
    display: none;
  }

  #lightbox-caption {
    width: calc(100% - 2rem);
    text-align: center;
    bottom: 1.2rem;
  }
}