:root {
  --bg-dark: #0a0e13;
  --bg-light: #f0f0ea;
  --surface: rgba(255,255,255,0.03);
  --ink-light: #f0f0ea;
  --ink-dark: #1a1a1a;
  --muted: rgba(240,240,234,0.5);
  --muted-dark: #6a6658;
  --accent: #2d6a5a;
  --accent-light: #3d8a72;
  --gold: #b8954e;
  --gold-light: #d4b76a;
  --rule: rgba(240,240,234,0.08);
  --rule-dark: rgba(26,26,26,0.1);
  --font-serif: 'Noto Serif SC', 'Source Han Serif SC', 'SimSun', serif;
  --font-sans: 'Noto Sans SC', 'PingFang SC', 'Microsoft YaHei', sans-serif;
}

* { margin: 0; padding: 0; box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  font-family: var(--font-sans);
  background: var(--bg-dark);
  color: var(--ink-light);
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}

::-webkit-scrollbar { width: 6px; }
::-webkit-scrollbar-track { background: var(--bg-dark); }
::-webkit-scrollbar-thumb { background: var(--accent); border-radius: 3px; }

.top-nav {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 1000;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 0;
  height: 64px;
  background: rgba(10,14,19,0.85);
  backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--rule);
  transition: all 0.4s ease;
}

.logo {
  position: absolute;
  left: 48px;
  top: 50%;
  transform: translateY(-50%);
  display: flex;
  align-items: center;
  gap: 0;
  font-family: 'PingFang SC', 'Hiragino Sans GB', 'Noto Sans SC', 'Microsoft YaHei', sans-serif;
  font-size: 1.1rem;
  font-weight: 500;
  letter-spacing: 0.08em;
  color: var(--ink-light);
}

.nav-search-wrap {
  position: absolute;
  left: 50%;
  top: 50%;
  transform: translate(-50%, -50%);
  width: min(420px, 36vw);
  height: 36px;
  display: flex;
  align-items: center;
  background: transparent;
  border: 0.5px solid var(--gold);
  border-radius: 999px;
  box-shadow: none;
  overflow: hidden;
  transition: border-color 0.3s ease, box-shadow 0.3s ease;
}

.nav-search-wrap:focus-within {
  border-color: var(--gold-light);
  box-shadow: 0 0 0 0.5px var(--gold-light);
}

.nav-search-wrap::before {
  content: '';
  width: 44px;
  height: 100%;
  flex: 0 0 44px;
  background: transparent;
  border-right: 0.5px solid var(--gold);
}

.nav-search-wrap::after {
  content: '⌕';
  position: absolute;
  left: 15px;
  top: 50%;
  transform: translateY(-52%);
  color: var(--gold);
  font-size: 1.18rem;
  line-height: 1;
}

.nav-search {
  width: 100%;
  height: 100%;
  border: 0;
  outline: none;
  background: transparent;
  color: var(--ink-light);
  font-family: 'PingFang SC', 'Hiragino Sans GB', 'Noto Sans SC', 'Microsoft YaHei', sans-serif;
  font-size: 0.82rem;
  font-weight: 400;
  letter-spacing: 0.06em;
  padding: 0 14px;
}

.nav-search::placeholder {
  color: var(--muted);
}

.nav-links {
  position: absolute;
  right: 48px;
  top: 50%;
  transform: translateY(-50%);
  display: flex;
  gap: 36px;
  list-style: none;
}

.nav-links a {
  color: var(--muted);
  text-decoration: none;
  font-size: 0.85rem;
  font-weight: 400;
  letter-spacing: 0.08em;
  transition: color 0.3s ease;
  position: relative;
}

.nav-links a::after {
  content: '';
  position: absolute;
  bottom: -4px; left: 0;
  width: 0; height: 1px;
  background: var(--gold);
  transition: width 0.3s ease;
}

.nav-links a:hover {
  color: var(--ink-light);
}

.nav-links a:hover::after {
  width: 100%;
}

.hero {
  position: relative;
  width: 100%;
  height: 100vh;
  min-height: 700px;
  background: var(--bg-dark);
  display: flex;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  inset: 0;
  background: radial-gradient(ellipse at 50% 60%, rgba(45,106,90,0.08) 0%, transparent 60%);
  pointer-events: none;
}

.era-nav {
  position: relative;
  z-index: 10;
  width: 200px;
  height: 100%;
  display: flex;
  flex-direction: column;
  justify-content: center;
  padding-left: 48px;
  border-right: 1px solid var(--rule);
}

.era-nav-label {
  font-size: 0.65rem;
  letter-spacing: 0.25em;
  text-transform: uppercase;
  color: var(--muted);
  margin-bottom: 24px;
  font-weight: 400;
}

.era-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.era-item {
  position: relative;
  padding: 8px 0;
  cursor: pointer;
  transition: all 0.3s ease;
}

.era-item::before {
  content: '';
  position: absolute;
  left: -16px; top: 50%;
  transform: translateY(-50%);
  width: 3px; height: 0;
  background: var(--gold);
  border-radius: 2px;
  transition: height 0.3s ease;
}

.era-item.active::before,
.era-item:hover::before {
  height: 20px;
}

.era-item span {
  font-family: var(--font-serif);
  font-size: 0.95rem;
  color: var(--muted);
  transition: color 0.3s ease;
  display: block;
}

.era-item small {
  font-size: 0.7rem;
  color: rgba(240,240,234,0.25);
  letter-spacing: 0.05em;
  display: block;
  margin-top: 2px;
}

.era-item.active span,
.era-item:hover span {
  color: var(--ink-light);
}

.era-item.active span {
  color: var(--gold);
}

.viewer-center {
  flex: 1;
  position: relative;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  perspective: 1200px;
  transform-style: preserve-3d;
}

#jade-canvas {
  width: 100%;
  height: 100%;
  position: absolute;
  inset: 0;
}

.jade-container {
  position: absolute;
  left: 50%;
  top: 53%;
  width: min(36vw, 440px);
  max-width: 520px;
  max-height: 48vh;
  z-index: 8;
  pointer-events: none;
  opacity: 0;
  transform: translate(-50%, -50%);
  transform-origin: 50% 50%;
  transform-style: preserve-3d;
  filter: drop-shadow(0 30px 34px rgba(0, 0, 0, 0.42)) drop-shadow(0 0 24px rgba(184, 149, 78, 0.16));
  transition: opacity 0.35s ease;
  will-change: transform;
}

.jade-container.is-visible {
  opacity: 1;
}

.jade-face {
  position: absolute;
  left: 50%;
  top: 50%;
  width: 100%;
  max-height: 48vh;
  object-fit: contain;
  transform: translate(-50%, -50%);
  backface-visibility: hidden;
  pointer-events: none;
}

.jade-face.back {
  transform: translate(-50%, -50%) rotateY(180deg);
}

.viewer-overlay {
  position: absolute;
  inset: 0;
  pointer-events: none;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
}

.viewer-title {
  position: absolute;
  top: 100px;
  text-align: center;
  pointer-events: none;
}

.viewer-title h1 {
  font-family: var(--font-serif);
  font-size: 2.8rem;
  font-weight: 700;
  letter-spacing: 0.2em;
  color: var(--ink-light);
  margin-bottom: 8px;
}

.viewer-title .subtitle {
  font-size: 0.8rem;
  letter-spacing: 0.3em;
  color: var(--muted);
  font-weight: 300;
}

.viewer-title .divider {
  width: 40px;
  height: 1px;
  background: var(--gold);
  margin: 16px auto;
}

.viewer-controls {
  position: absolute;
  bottom: 60px;
  display: flex;
  gap: 16px;
  pointer-events: auto;
  z-index: 20;
}

.ctrl-btn {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 10px 24px;
  background: rgba(255,255,255,0.05);
  border: 1px solid var(--rule);
  border-radius: 4px;
  color: var(--muted);
  font-family: var(--font-sans);
  font-size: 0.8rem;
  letter-spacing: 0.1em;
  cursor: pointer;
  transition: all 0.3s ease;
  backdrop-filter: blur(10px);
}

.ctrl-btn:hover {
  background: rgba(184,149,78,0.1);
  border-color: var(--gold);
  color: var(--ink-light);
}

.ctrl-btn.active {
  background: rgba(45,106,90,0.2);
  border-color: var(--accent-light);
  color: var(--ink-light);
}

.ctrl-btn svg {
  width: 16px; height: 16px;
  fill: currentColor;
}

.drag-hint {
  position: absolute;
  bottom: 130px;
  font-size: 0.75rem;
  color: rgba(240,240,234,0.25);
  letter-spacing: 0.1em;
  display: flex;
  align-items: center;
  gap: 8px;
  animation: pulse 3s ease-in-out infinite;
}

@keyframes pulse {
  0%, 100% { opacity: 0.3; }
  50% { opacity: 0.7; }
}

.info-panel {
  position: relative;
  z-index: 10;
  width: 320px;
  height: 100%;
  padding: 100px 48px 60px 0;
  display: flex;
  flex-direction: column;
  justify-content: center;
  border-left: 1px solid var(--rule);
}

.info-content {
  padding-left: 36px;
}

.info-era {
  font-size: 0.65rem;
  letter-spacing: 0.25em;
  color: var(--gold);
  text-transform: uppercase;
  margin-bottom: 12px;
}

.info-name {
  font-family: var(--font-serif);
  font-size: 1.8rem;
  font-weight: 700;
  color: var(--ink-light);
  margin-bottom: 6px;
  letter-spacing: 0.1em;
}

.info-name-en {
  font-size: 0.75rem;
  color: var(--muted);
  letter-spacing: 0.15em;
  margin-bottom: 24px;
  font-weight: 300;
}

.info-divider {
  width: 30px;
  height: 1px;
  background: var(--gold);
  margin-bottom: 24px;
}

.info-desc {
  font-size: 0.85rem;
  line-height: 1.9;
  color: var(--muted);
  margin-bottom: 32px;
  font-weight: 300;
  text-align: justify;
  text-align-last: left;
  text-justify: inter-character;
  word-break: normal;
  overflow-wrap: normal;
  letter-spacing: 0.015em;
}

.info-specs {
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.spec-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding-bottom: 10px;
  border-bottom: 1px solid var(--rule);
}

.spec-label {
  font-size: 0.75rem;
  color: var(--muted);
  letter-spacing: 0.08em;
}

.spec-value {
  font-size: 0.8rem;
  color: var(--ink-light);
  font-weight: 500;
  font-family: var(--font-serif);
}

.gallery-section {
  background: var(--bg-light);
  padding: 100px 48px;
  position: relative;
}

.gallery-header {
  text-align: center;
  margin-bottom: 64px;
}

.gallery-header h2 {
  font-family: var(--font-serif);
  font-size: 2rem;
  font-weight: 700;
  color: var(--ink-dark);
  letter-spacing: 0.15em;
  margin-bottom: 12px;
}

.gallery-header p {
  font-size: 0.85rem;
  color: var(--muted-dark);
  letter-spacing: 0.1em;
  font-weight: 300;
}

.gallery-header .divider {
  width: 40px;
  height: 1px;
  background: var(--gold);
  margin: 20px auto 0;
}

.gallery-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
  max-width: 1400px;
  margin: 0 auto;
}

.gallery-card {
  position: relative;
  background: #fff;
  border-radius: 8px;
  overflow: hidden;
  cursor: pointer;
  transition: all 0.4s cubic-bezier(0.25, 0.46, 0.45, 0.94);
  box-shadow: 0 2px 12px rgba(0,0,0,0.06);
}

.gallery-card:hover {
  transform: translateY(-8px);
  box-shadow: 0 16px 40px rgba(0,0,0,0.12);
}

.gallery-card.is-hidden {
  display: none;
}

.gallery-card-img {
  width: 100%;
  aspect-ratio: 1;
  object-fit: cover;
  display: block;
  transition: transform 0.6s ease;
}

.gallery-card:hover .gallery-card-img {
  transform: scale(1.05);
}

.gallery-card-info {
  padding: 20px 20px 24px;
}

.card-era {
  font-size: 0.65rem;
  letter-spacing: 0.2em;
  color: var(--gold);
  text-transform: uppercase;
  margin-bottom: 6px;
}

.card-name {
  font-family: var(--font-serif);
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--ink-dark);
  margin-bottom: 4px;
}

.card-name-en {
  font-size: 0.7rem;
  color: var(--muted-dark);
  letter-spacing: 0.05em;
}

.museum-wall {
  background: var(--bg-light);
  padding: 0 48px 96px;
}

.museum-wall-inner {
  max-width: 1400px;
  margin: 0 auto;
  padding-top: 56px;
  border-top: 1px solid var(--rule-dark);
}

.museum-wall-header {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: 24px;
  margin-bottom: 32px;
}

.museum-wall-title {
  font-family: 'PingFang SC', 'Hiragino Sans GB', 'Noto Sans SC', 'Microsoft YaHei', sans-serif;
  font-size: 1.1rem;
  font-weight: 500;
  letter-spacing: 0.14em;
  color: var(--ink-dark);
}

.museum-wall-subtitle {
  font-size: 0.7rem;
  letter-spacing: 0.22em;
  color: var(--muted-dark);
  text-transform: uppercase;
}

.museum-logo-grid {
  display: grid;
  grid-template-columns: repeat(6, 1fr);
  border-top: 0.5px solid var(--rule-dark);
  border-left: 0.5px solid var(--rule-dark);
}

.museum-logo {
  min-height: 104px;
  padding: 18px 16px;
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: 8px;
  border-right: 0.5px solid var(--rule-dark);
  border-bottom: 0.5px solid var(--rule-dark);
  background: rgba(255,255,255,0.28);
  transition: background 0.3s ease, transform 0.3s ease;
}

.museum-logo:hover {
  background: rgba(255,255,255,0.58);
  transform: translateY(-2px);
}

.museum-logo-mark {
  font-family: var(--font-serif);
  font-size: 1.2rem;
  font-weight: 700;
  line-height: 1;
  color: var(--gold);
  letter-spacing: 0.08em;
}

.museum-logo-name {
  font-family: 'PingFang SC', 'Hiragino Sans GB', 'Noto Sans SC', 'Microsoft YaHei', sans-serif;
  font-size: 0.82rem;
  font-weight: 500;
  color: var(--ink-dark);
  letter-spacing: 0.08em;
  white-space: nowrap;
}

.museum-logo-en {
  font-size: 0.58rem;
  line-height: 1.4;
  color: var(--muted-dark);
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.footer {
  background: var(--bg-dark);
  padding: 48px;
  text-align: center;
  border-top: 1px solid var(--rule);
}

.footer p {
  font-size: 0.75rem;
  color: var(--muted);
  letter-spacing: 0.1em;
}

.loading-screen {
  position: fixed;
  inset: 0;
  background: var(--bg-dark);
  z-index: 9999;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  transition: opacity 0.8s ease, visibility 0.8s ease;
}

.loading-screen.hidden {
  opacity: 0;
  visibility: hidden;
}

.loading-spinner {
  width: 40px;
  height: 40px;
  border: 2px solid var(--rule);
  border-top-color: var(--gold);
  border-radius: 50%;
  animation: spin 1s linear infinite;
  margin-bottom: 20px;
}

@keyframes spin {
  to { transform: rotate(360deg); }
}

.loading-text {
  font-family: var(--font-serif);
  font-size: 0.9rem;
  color: var(--muted);
  letter-spacing: 0.2em;
}

@media (max-width: 1200px) {
  .era-nav { width: 160px; padding-left: 24px; }
  .logo { left: 24px; }
  .info-panel { width: 260px; padding-right: 24px; }
  .gallery-grid { grid-template-columns: repeat(3, 1fr); }
  .museum-logo-grid { grid-template-columns: repeat(4, 1fr); }
}

@media (max-width: 900px) {
  .era-nav, .info-panel { display: none; }
  .viewer-title h1 { font-size: 2rem; }
  .gallery-grid { grid-template-columns: repeat(2, 1fr); }
  .nav-search-wrap { width: 40vw; }
  .nav-links { display: none; }
  .museum-logo-grid { grid-template-columns: repeat(3, 1fr); }
}

@media (max-width: 600px) {
  .gallery-section { padding: 60px 24px; }
  .gallery-grid { grid-template-columns: 1fr; }
  .viewer-title h1 { font-size: 1.5rem; }
  .ctrl-btn { padding: 8px 16px; font-size: 0.7rem; }
  .nav-search-wrap { display: none; }
  .museum-wall { padding: 0 24px 64px; }
  .museum-wall-header { display: block; }
  .museum-wall-subtitle { margin-top: 8px; }
  .museum-logo-grid { grid-template-columns: repeat(2, 1fr); }
  .museum-logo { min-height: 92px; padding: 14px 12px; }
  .museum-logo-name { font-size: 0.76rem; }
}