/* ─── Reset & Base ─────────────────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --bg:         #F2EBDC;
  --bg-alt:     #EDE5D4;
  --card:       #FDFAF5;
  --text:       #333333;
  --muted:      #666666;
  --border:     rgba(42,80,70,0.15);
  --primary:    #2A5046;
  --river:      #406887;
  --terra:      #A65C41;
  --nav-bg:     rgba(242,235,220,0.96);
  --hero-overlay: rgba(20,40,30,0.32);
  --section-alt: #EAE3D3;
  --footer-bg:  #2A5046;
}

/* ── 昼夜切换：checkbox:checked 触发全站色彩 ── */
body:has(#night-toggle:checked) {
  --bg:         #0d1b2a;
  --bg-alt:     #0f2030;
  --card:       #162a3e;
  --text:       #e8dcc8;
  --muted:      #8aa0b0;
  --border:     rgba(64,104,135,0.25);
  --primary:    #4a8070;
  --nav-bg:     rgba(10,20,35,0.97);
  --hero-overlay: rgba(0,10,25,0.60);
  --section-alt: #0d1e2d;
  --footer-bg:  #0a1520;
}

html { scroll-behavior: smooth; }

body {
  background: var(--bg);
  color: var(--text);
  font-family: 'Inter', sans-serif;
  transition: background 0.8s ease, color 0.8s ease;
  overflow-x: hidden;
}

img { display: block; width: 100%; height: 100%; object-fit: cover; }

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

/* ─── 导航栏 ────────────────────────────────────────────────────────── */
.nav {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 100;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1rem 3rem;
  background: var(--nav-bg);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border-bottom: 1px solid var(--border);
  transition: background 0.8s ease, border-color 0.8s ease;
}

.nav-logo {
  display: flex;
  flex-direction: column;
  line-height: 1.2;
}
.logo-zh {
  font-family: 'Noto Serif SC', serif;
  font-size: 1.3rem;
  font-weight: 600;
  color: var(--primary);
  letter-spacing: 0.08em;
  transition: color 0.8s ease;
}
.logo-en {
  font-family: 'Lora', serif;
  font-style: italic;
  font-size: 0.58rem;
  color: var(--muted);
  letter-spacing: 0.05em;
  transition: color 0.8s ease;
}

.nav-links {
  display: flex;
  gap: 2rem;
}
.nav-links a {
  font-family: 'Noto Serif SC', serif;
  font-size: 0.85rem;
  color: var(--primary);
  letter-spacing: 0.05em;
  position: relative;
  padding-bottom: 2px;
  transition: color 0.3s ease;
}
.nav-links a::after {
  content: '';
  position: absolute;
  bottom: 0; left: 0;
  width: 0; height: 1.5px;
  background: var(--terra);
  transition: width 0.35s ease;
}
.nav-links a:hover::after { width: 100%; }

/* 昼夜切换按钮 */
.night-btn {
  display: flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.45rem 1.1rem;
  border: 1px solid var(--border);
  border-radius: 2rem;
  cursor: pointer;
  font-family: 'Noto Serif SC', serif;
  font-size: 0.78rem;
  color: var(--text);
  background: transparent;
  transition: all 0.4s ease;
  white-space: nowrap;
}
.night-btn:hover { border-color: var(--primary); }
.icon-night { display: none; }

body:has(#night-toggle:checked) .icon-day  { display: none; }
body:has(#night-toggle:checked) .icon-night { display: inline; }

/* ─── Hero ──────────────────────────────────────────────────────────── */
.hero {
  position: relative;
  height: 100vh;
  min-height: 600px;
  overflow: hidden;
  display: flex;
  align-items: center;
  justify-content: center;
}

.hero-mountain {
  position: absolute;
  inset: -10% 0 0 0;
  background-image: url('https://images.unsplash.com/photo-1537228710341-ca26f67b7578?w=1920&h=1080&fit=crop&auto=format');
  background-size: cover;
  background-position: center;
  background-attachment: fixed;
  transition: filter 0.8s ease;
}
body:has(#night-toggle:checked) .hero-mountain {
  filter: brightness(0.45) saturate(0.6);
}

.hero-river {
  position: absolute;
  bottom: 0; left: 0; right: 0;
  height: 45%;
  background-image: url('https://images.unsplash.com/photo-1729437976233-e41dc3f1d686?w=1920&h=600&fit=crop&auto=format');
  background-size: cover;
  background-position: center top;
  mask-image: linear-gradient(180deg, transparent 0%, black 40%);
  -webkit-mask-image: linear-gradient(180deg, transparent 0%, black 40%);
  transition: filter 0.8s ease;
}
body:has(#night-toggle:checked) .hero-river {
  filter: brightness(0.4) saturate(0.5) hue-rotate(20deg);
}

.hero-overlay {
  position: absolute;
  inset: 0;
  background: var(--hero-overlay);
  transition: background 0.8s ease;
}

/* 云朵装饰 */
.cloud {
  position: absolute;
  border-radius: 50%;
  background: radial-gradient(ellipse, rgba(255,255,255,0.5) 0%, transparent 70%);
  animation: floatCloud linear infinite;
  pointer-events: none;
}
.cloud-1 { width: 220px; height: 90px; top: 15%; left: 8%;  animation-duration: 30s; }
.cloud-2 { width: 160px; height: 65px; top: 22%; left: 55%; animation-duration: 24s; animation-delay: -8s; }
.cloud-3 { width: 280px; height: 110px; top: 10%; left: 72%; animation-duration: 36s; animation-delay: -14s; }

@keyframes floatCloud {
  0%   { transform: translateX(0) translateY(0); }
  33%  { transform: translateX(18px) translateY(-8px); }
  66%  { transform: translateX(-10px) translateY(-14px); }
  100% { transform: translateX(0) translateY(0); }
}
body:has(#night-toggle:checked) .cloud {
  background: radial-gradient(ellipse, rgba(80,110,150,0.2) 0%, transparent 70%);
}

/* Hero 文字 */
.hero-content {
  position: relative;
  z-index: 2;
  text-align: center;
  animation: heroFadeUp 1.2s ease both;
}
@keyframes heroFadeUp {
  from { opacity: 0; transform: translateY(40px); }
  to   { opacity: 1; transform: translateY(0); }
}

.hero-zh {
  font-family: 'Noto Serif SC', serif;
  font-size: clamp(3.5rem, 9vw, 7rem);
  font-weight: 300;
  color: #F2EBDC;
  letter-spacing: 0.25em;
  text-shadow: 0 4px 30px rgba(0,0,0,0.4);
  animation: heroFadeUp 1.2s 0.2s ease both;
}
.hero-en {
  font-family: 'Lora', serif;
  font-style: italic;
  font-size: clamp(0.9rem, 2vw, 1.3rem);
  color: rgba(242,235,220,0.82);
  letter-spacing: 0.07em;
  margin-top: 1rem;
  animation: heroFadeUp 1.2s 0.8s ease both;
}
.hero-sub {
  font-family: 'Noto Serif SC', serif;
  font-size: clamp(0.85rem, 1.5vw, 1.1rem);
  font-weight: 300;
  color: rgba(242,235,220,0.58);
  letter-spacing: 0.28em;
  margin-top: 0.9rem;
  animation: heroFadeUp 1.2s 1.4s ease both;
}
.hero-divider {
  width: 40px; height: 1px;
  background: rgba(242,235,220,0.4);
  margin: 1.5rem auto 0;
  animation: heroFadeUp 1.2s 1.8s ease both;
}

/* Scroll hint */
.hero-scroll {
  position: absolute;
  bottom: 2.5rem;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.5rem;
  z-index: 2;
  animation: heroFadeUp 1.2s 2.2s ease both;
}
.scroll-line {
  display: block;
  width: 1px; height: 50px;
  background: linear-gradient(180deg, transparent, rgba(242,235,220,0.6));
  animation: scrollPulse 2s ease-in-out infinite;
}
@keyframes scrollPulse {
  0%, 100% { opacity: 0.4; }
  50%       { opacity: 1; }
}
.scroll-text {
  font-size: 0.6rem;
  letter-spacing: 0.2em;
  color: rgba(242,235,220,0.45);
  font-family: 'Inter', sans-serif;
}

/* ─── 通用 Section ──────────────────────────────────────────────────── */
.section {
  padding: 6rem 0;
  background: var(--bg);
  transition: background 0.8s ease;
}
.section-alt {
  background: var(--section-alt);
}
.section-river {
  background: linear-gradient(180deg, var(--bg-alt) 0%, var(--bg) 100%);
}
body:has(#night-toggle:checked) .section-river {
  background: linear-gradient(180deg, #091522 0%, #0d1b2a 100%);
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 3rem;
}

.section-header {
  text-align: center;
  margin-bottom: 3.5rem;
}
.section-zh {
  font-family: 'Noto Serif SC', serif;
  font-size: clamp(1.8rem, 4vw, 2.8rem);
  font-weight: 400;
  color: var(--text);
  letter-spacing: 0.18em;
  transition: color 0.8s ease;
}
.section-en {
  font-family: 'Lora', serif;
  font-style: italic;
  font-size: 1rem;
  color: var(--muted);
  letter-spacing: 0.08em;
  margin-top: 0.4rem;
  transition: color 0.8s ease;
}
.section-line {
  width: 50px; height: 1.5px;
  background: var(--terra);
  margin: 1rem auto 0;
}

/* ─── 景点卡片（岳麓）──────────────────────────────────────────────── */
.cards-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1.5rem;
}

.spot-card {
  position: relative;
  border-radius: 2px;
  overflow: hidden;
  cursor: pointer;
  box-shadow: 0 4px 20px rgba(0,0,0,0.08);
  transition: box-shadow 0.4s ease, transform 0.4s ease;
}
.spot-card:hover {
  box-shadow: 0 20px 45px rgba(0,0,0,0.2);
  transform: translateY(-4px);
}

.card-img-wrap {
  position: relative;
  height: 280px;
  overflow: hidden;
}
.card-img-wrap img {
  transition: transform 0.6s ease;
}
.spot-card:hover .card-img-wrap img {
  transform: scale(1.07);
}

.card-overlay {
  position: absolute;
  inset: 0;
  background: linear-gradient(180deg, transparent 40%, rgba(0,0,0,0.75) 100%);
}

.card-body {
  position: absolute;
  bottom: 0; left: 0; right: 0;
  padding: 1.25rem;
  transition: transform 0.4s ease;
}
.spot-card:hover .card-body {
  transform: translateY(-2.8rem);
}

.card-zh {
  font-family: 'Noto Serif SC', serif;
  font-size: 1.15rem;
  font-weight: 500;
  color: #F2EBDC;
  letter-spacing: 0.08em;
  margin-bottom: 0.2rem;
}
.card-en {
  font-family: 'Lora', serif;
  font-style: italic;
  font-size: 0.72rem;
  color: rgba(242,235,220,0.72);
}
.card-poem {
  font-family: 'Noto Serif SC', serif;
  font-size: 0.72rem;
  color: rgba(242,235,220,0.85);
  border-left: 2px solid var(--terra);
  padding-left: 0.75rem;
  margin-top: 0.8rem;
  line-height: 1.6;
  opacity: 0;
  transform: translateY(8px);
  transition: opacity 0.4s ease 0.1s, transform 0.4s ease 0.1s;
}
.spot-card:hover .card-poem {
  opacity: 1;
  transform: translateY(0);
}

/* ─── 湘江卡片 ──────────────────────────────────────────────────────── */
.river-card {
  position: relative;
  height: 300px;
  border-radius: 2px;
  overflow: hidden;
  cursor: pointer;
  box-shadow: 0 4px 20px rgba(0,0,0,0.1);
  transition: box-shadow 0.4s ease;
}
.river-card:hover { box-shadow: 0 16px 40px rgba(0,0,0,0.25); }
.river-card img {
  transition: transform 0.6s ease, filter 0.8s ease;
}
.river-card:hover img { transform: scale(1.05); }

body:has(#night-toggle:checked) .river-card img {
  filter: brightness(0.45) saturate(0.6);
}

.river-card-info {
  position: absolute;
  bottom: 0; left: 0; right: 0;
  padding: 1.25rem;
  background: linear-gradient(180deg, transparent, rgba(0,0,0,0.72));
}
.river-card-info h3 {
  font-family: 'Noto Serif SC', serif;
  font-size: 1.1rem;
  font-weight: 500;
  color: #F2EBDC;
  letter-spacing: 0.06em;
}
.river-card-info p {
  font-family: 'Lora', serif;
  font-style: italic;
  font-size: 0.7rem;
  color: rgba(242,235,220,0.7);
  margin-top: 0.2rem;
}

/* Popup on hover */
.river-popup {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 2rem;
  background: rgba(0,0,0,0.65);
  opacity: 0;
  transition: opacity 0.4s ease;
}
.has-popup:hover .river-popup { opacity: 1; }
.river-popup p {
  font-family: 'Noto Serif SC', serif;
  font-size: 1rem;
  color: #F2EBDC;
  text-align: center;
  line-height: 1.9;
  letter-spacing: 0.06em;
  border-left: 2px solid var(--terra);
  padding-left: 1rem;
}

/* 江面波纹装饰 */
.wave-wrap {
  display: flex;
  flex-direction: column;
  gap: 6px;
  margin-bottom: 2.5rem;
  overflow: hidden;
}
.wave-bar {
  height: 2px;
  background: linear-gradient(90deg, transparent, var(--river), transparent);
  opacity: 0.35;
  animation: waveSweep 3s ease-in-out infinite;
}
.wave-bar:nth-child(2) { animation-delay: 0.4s; opacity: 0.25; }
.wave-bar:nth-child(3) { animation-delay: 0.8s; opacity: 0.18; }
@keyframes waveSweep {
  0%   { transform: translateX(-60%); }
  100% { transform: translateX(60%); }
}

/* ─── 湖湘文脉 ──────────────────────────────────────────────────────── */
.heritage-banner {
  position: relative;
  height: 200px;
  border-radius: 2px;
  overflow: hidden;
  margin-bottom: 4rem;
}
.heritage-banner img { filter: brightness(0.38) saturate(0.4); }
.heritage-banner-text {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: 'Noto Serif SC', serif;
  font-size: clamp(1rem, 2.5vw, 1.5rem);
  font-weight: 300;
  color: rgba(242,235,220,0.88);
  letter-spacing: 0.3em;
  text-shadow: 0 2px 20px rgba(0,0,0,0.5);
}

/* 时间轴 */
.timeline {
  position: relative;
  max-width: 900px;
  margin: 0 auto;
}
.timeline::before {
  content: '';
  position: absolute;
  left: 50%;
  top: 0; bottom: 0;
  width: 1px;
  background: linear-gradient(180deg, transparent, var(--primary), transparent);
  transform: translateX(-50%);
  transition: background 0.8s ease;
}

.timeline-item {
  position: relative;
  width: 46%;
  margin-bottom: 2.5rem;
}
.tl-left  { margin-left: 0; margin-right: auto; }
.tl-right { margin-left: auto; margin-right: 0; }

.tl-dot {
  position: absolute;
  top: 1.5rem;
  width: 12px; height: 12px;
  border-radius: 50%;
  background: var(--primary);
  transition: background 0.3s ease, box-shadow 0.3s ease;
  animation: glowPulse 3s ease-in-out infinite;
}
.tl-left  .tl-dot { right: -8%; }
.tl-right .tl-dot { left: -8%; }

@keyframes glowPulse {
  0%, 100% { box-shadow: 0 0 4px 1px rgba(42,80,70,0.3); }
  50%       { box-shadow: 0 0 12px 3px rgba(42,80,70,0.6); }
}

.tl-card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 2px;
  padding: 1.25rem 1.5rem;
  transition: background 0.8s ease, border-color 0.8s ease, box-shadow 0.3s ease;
  cursor: pointer;
}
.tl-card:hover { box-shadow: 0 8px 28px rgba(42,80,70,0.12); }
.tl-card[open] { box-shadow: 0 8px 28px rgba(42,80,70,0.15); }
.tl-card[open] .tl-dot { background: var(--terra); }

.tl-card summary {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 0.5rem;
  cursor: pointer;
}
.tl-card summary::-webkit-details-marker { display: none; }

.tl-year {
  font-family: 'Lora', serif;
  font-size: 0.75rem;
  color: var(--terra);
  letter-spacing: 0.08em;
}
.tl-era {
  font-family: 'Noto Serif SC', serif;
  font-size: 0.65rem;
  color: var(--muted);
}
.tl-title {
  font-family: 'Noto Serif SC', serif;
  font-size: 0.98rem;
  font-weight: 500;
  color: var(--text);
  letter-spacing: 0.04em;
  flex: 1;
  transition: color 0.8s ease;
}
.tl-arrow {
  font-size: 0.7rem;
  color: var(--muted);
  transition: transform 0.3s ease;
}
.tl-card[open] .tl-arrow { transform: rotate(180deg); }

.tl-desc {
  font-family: 'Inter', sans-serif;
  font-size: 0.82rem;
  color: var(--muted);
  line-height: 1.75;
  margin-top: 0.75rem;
  padding-top: 0.75rem;
  border-top: 1px solid var(--border);
  transition: color 0.8s ease;
}

/* ─── 卡片翻转（小众山水）──────────────────────────────────────────── */
.section-hint {
  text-align: center;
  font-family: 'Noto Serif SC', serif;
  font-size: 0.78rem;
  color: var(--muted);
  letter-spacing: 0.08em;
  margin-bottom: 2rem;
  transition: color 0.8s ease;
}

.flip-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1.5rem;
}

.flip-card {
  height: 320px;
  perspective: 1000px;
  cursor: pointer;
}

.flip-inner {
  position: relative;
  width: 100%; height: 100%;
  transform-style: preserve-3d;
  transition: transform 0.7s cubic-bezier(0.4, 0, 0.2, 1);
}
.flip-card:hover .flip-inner { transform: rotateY(180deg); }

.flip-front,
.flip-back {
  position: absolute;
  inset: 0;
  border-radius: 2px;
  overflow: hidden;
  backface-visibility: hidden;
  -webkit-backface-visibility: hidden;
}

.flip-front { background: #111; }
.flip-front img { width: 100%; height: 100%; transition: transform 0.6s ease; }
.flip-card:hover .flip-front img { transform: scale(1.05); }

.flip-front-info {
  position: absolute;
  bottom: 0; left: 0; right: 0;
  padding: 1.25rem;
  background: linear-gradient(180deg, transparent, rgba(0,0,0,0.72));
}
.flip-front-info h3 {
  font-family: 'Noto Serif SC', serif;
  font-size: 1.15rem;
  font-weight: 500;
  color: #F2EBDC;
}
.flip-front-info p {
  font-family: 'Lora', serif;
  font-style: italic;
  font-size: 0.72rem;
  color: rgba(242,235,220,0.7);
  margin-top: 0.2rem;
}

.flip-back {
  background: var(--card);
  border: 1px solid var(--border);
  transform: rotateY(180deg);
  display: flex;
  flex-direction: column;
  justify-content: center;
  padding: 2rem;
  transition: background 0.8s ease, border-color 0.8s ease;
}
.back-title {
  font-family: 'Noto Serif SC', serif;
  font-size: 1.2rem;
  font-weight: 500;
  color: var(--text);
  margin-bottom: 0.75rem;
  transition: color 0.8s ease;
}
.back-desc {
  font-family: 'Noto Serif SC', serif;
  font-size: 0.85rem;
  color: var(--text);
  line-height: 1.75;
  border-left: 2px solid var(--terra);
  padding-left: 0.9rem;
  margin-bottom: 1.25rem;
  transition: color 0.8s ease;
}
.back-meta {
  display: flex;
  gap: 0.6rem;
  align-items: flex-start;
  margin-bottom: 0.5rem;
  font-family: 'Inter', sans-serif;
  font-size: 0.78rem;
  color: var(--muted);
  transition: color 0.8s ease;
}
.meta-label {
  color: var(--terra);
  font-family: 'Noto Serif SC', serif;
  font-size: 0.7rem;
  flex-shrink: 0;
  padding-top: 1px;
}

/* ─── 行游贴士 ──────────────────────────────────────────────────────── */
.tips-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.5rem;
  margin-bottom: 3.5rem;
}
.tip-card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 2px;
  padding: 2rem;
  transition: background 0.8s ease, border-color 0.8s ease, transform 0.3s ease, box-shadow 0.3s ease;
}
.tip-card:hover {
  transform: translateY(-3px);
  box-shadow: 0 10px 30px rgba(0,0,0,0.08);
}
.tip-icon { font-size: 2rem; margin-bottom: 0.75rem; }
.tip-card h3 {
  font-family: 'Noto Serif SC', serif;
  font-size: 1rem;
  font-weight: 500;
  color: var(--text);
  margin-bottom: 0.75rem;
  letter-spacing: 0.04em;
  transition: color 0.8s ease;
}
.tip-card p {
  font-family: 'Inter', sans-serif;
  font-size: 0.82rem;
  color: var(--muted);
  line-height: 1.75;
  transition: color 0.8s ease;
}

/* 路线选择器 */
.route-section {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 2px;
  padding: 2.5rem;
  transition: background 0.8s ease, border-color 0.8s ease;
}
.route-title {
  font-family: 'Noto Serif SC', serif;
  font-size: 1.15rem;
  font-weight: 500;
  color: var(--text);
  letter-spacing: 0.06em;
  margin-bottom: 1.5rem;
  transition: color 0.8s ease;
}
.route-btns {
  display: flex;
  gap: 0.75rem;
  flex-wrap: wrap;
  margin-bottom: 1.5rem;
}
.route-btn {
  padding: 0.5rem 1.5rem;
  border: 1px solid var(--border);
  border-radius: 2rem;
  cursor: pointer;
  font-family: 'Noto Serif SC', serif;
  font-size: 0.85rem;
  color: var(--text);
  background: transparent;
  transition: all 0.3s ease;
  letter-spacing: 0.05em;
}
.route-btn:hover {
  border-color: var(--primary);
  color: var(--primary);
}

/* Radio 选中态 */
#route-a:checked ~ * #btn-a,
#route-b:checked ~ * #btn-b,
#route-c:checked ~ * #btn-c {
  background: var(--primary);
  color: #F2EBDC;
  border-color: var(--primary);
}

.route-result {
  display: none;
  animation: fadeUp 0.4s ease;
}
@keyframes fadeUp {
  from { opacity: 0; transform: translateY(10px); }
  to   { opacity: 1; transform: translateY(0); }
}

/* 路线结果显示 */
#route-a:checked ~ * #result-a,
#route-b:checked ~ * #result-b,
#route-c:checked ~ * #result-c {
  display: block;
}

.route-desc {
  font-family: 'Noto Serif SC', serif;
  font-size: 0.9rem;
  color: var(--muted);
  letter-spacing: 0.06em;
  margin-bottom: 1rem;
  transition: color 0.8s ease;
}
.route-highlights {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
}
.route-highlights span {
  font-family: 'Noto Serif SC', serif;
  font-size: 0.8rem;
  color: var(--text);
  background: rgba(42,80,70,0.08);
  padding: 0.45rem 1rem;
  border-radius: 2px;
  transition: color 0.8s ease;
}

/* ─── 页脚 ───────────────────────────────────────────────────────────── */
.footer {
  background: var(--footer-bg);
  position: relative;
  overflow: hidden;
  padding: 5rem 3rem 3rem;
  text-align: center;
  transition: background 0.8s ease;
}

.footer-mountains {
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 120px;
  pointer-events: none;
}
.footer-mountains svg {
  width: 100%; height: 100%;
}

.footer-content { position: relative; z-index: 1; }

.footer-zh {
  font-family: 'Noto Serif SC', serif;
  font-size: clamp(1.8rem, 4vw, 3rem);
  font-weight: 300;
  color: #F2EBDC;
  letter-spacing: 0.2em;
  margin-bottom: 0.75rem;
}
.footer-en {
  font-family: 'Lora', serif;
  font-style: italic;
  font-size: 1rem;
  color: rgba(242,235,220,0.6);
  letter-spacing: 0.05em;
}
.footer-line {
  width: 40px; height: 1px;
  background: rgba(242,235,220,0.25);
  margin: 2rem auto;
}
.back-top {
  display: inline-block;
  border: 1px solid rgba(242,235,220,0.3);
  border-radius: 2rem;
  padding: 0.6rem 1.5rem;
  color: rgba(242,235,220,0.7);
  font-family: 'Noto Serif SC', serif;
  font-size: 0.8rem;
  letter-spacing: 0.1em;
  transition: all 0.3s ease;
}
.back-top:hover {
  border-color: rgba(242,235,220,0.75);
  color: #F2EBDC;
}
.footer-copy {
  font-family: 'Inter', sans-serif;
  font-size: 0.65rem;
  color: rgba(242,235,220,0.28);
  letter-spacing: 0.1em;
  margin-top: 2rem;
}

/* ─── 滚动渐入动画 ──────────────────────────────────────────────────── */
@keyframes revealUp {
  from { opacity: 0; transform: translateY(35px); }
  to   { opacity: 1; transform: translateY(0); }
}

.spot-card   { animation: revealUp 0.7s ease both; }
.spot-card:nth-child(1) { animation-delay: 0.1s; }
.spot-card:nth-child(2) { animation-delay: 0.25s; }
.spot-card:nth-child(3) { animation-delay: 0.4s; }
.spot-card:nth-child(4) { animation-delay: 0.55s; }

.river-card  { animation: revealUp 0.7s ease both; }
.river-card:nth-child(1) { animation-delay: 0.1s; }
.river-card:nth-child(2) { animation-delay: 0.25s; }
.river-card:nth-child(3) { animation-delay: 0.4s; }
.river-card:nth-child(4) { animation-delay: 0.55s; }

.flip-card   { animation: revealUp 0.7s ease both; }
.flip-card:nth-child(1) { animation-delay: 0.1s; }
.flip-card:nth-child(2) { animation-delay: 0.25s; }
.flip-card:nth-child(3) { animation-delay: 0.4s; }
.flip-card:nth-child(4) { animation-delay: 0.55s; }

.tip-card    { animation: revealUp 0.7s ease both; }
.tip-card:nth-child(1) { animation-delay: 0.1s; }
.tip-card:nth-child(2) { animation-delay: 0.25s; }
.tip-card:nth-child(3) { animation-delay: 0.4s; }

.timeline-item { animation: revealUp 0.7s ease both; }
.timeline-item:nth-child(1) { animation-delay: 0.1s; }
.timeline-item:nth-child(2) { animation-delay: 0.3s; }
.timeline-item:nth-child(3) { animation-delay: 0.5s; }
.timeline-item:nth-child(4) { animation-delay: 0.7s; }

/* ─── 响应式 ────────────────────────────────────────────────────────── */
@media (max-width: 1024px) {
  .cards-grid, .flip-grid { grid-template-columns: repeat(2, 1fr); }
  .tips-grid { grid-template-columns: repeat(2, 1fr); }
  .nav-links { gap: 1.2rem; }
  .container { padding: 0 2rem; }
}

@media (max-width: 680px) {
  .cards-grid, .flip-grid, .tips-grid { grid-template-columns: 1fr; }
  .nav { padding: 0.8rem 1.25rem; }
  .nav-links { display: none; }
  .timeline::before { left: 16px; }
  .timeline-item { width: 100%; margin-left: 2.5rem; }
  .tl-left .tl-dot, .tl-right .tl-dot { left: -2.1rem; right: auto; }
  .section { padding: 4rem 0; }
  .footer { padding: 4rem 1.5rem 2.5rem; }
}