:root {
  --c-bg: #0A192F;
  --c-surface: #112240;
  --c-border: #2A4F7E;
  --c-accent: #FF6B35;
  --c-accent-dark: #E05A24;
  --c-lime: #39FF14;
  --c-lime-dark: #28C112;
  --c-text: #FFFFFF;
  --c-text-dim: #AAC3D4;
  --font-sans: 'Inter', 'PingFang SC', 'Microsoft YaHei', 'Helvetica Neue', Arial, sans-serif;
  --font-mono: 'Roboto Mono', 'SFMono-Regular', Consolas, monospace;
  --container-max: 1440px;
  --sidebar-w: 280px;
  --header-h: 64px;
  --space-1: 8px;
  --space-2: 16px;
  --space-3: 24px;
  --space-4: 48px;
  --space-5: 80px;
  --transition: 200ms ease-out;
}

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

html {
  scroll-behavior: smooth;
  height: 100%;
}

body {
  font-family: var(--font-sans);
  font-size: 1.125rem;
  font-weight: 400;
  line-height: 1.7;
  color: var(--c-text);
  background-color: var(--c-bg);
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
  margin-left: var(--sidebar-w);
}

body::before {
  content: '';
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
  background: var(--c-accent);
  z-index: 3000;
}

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

a {
  color: var(--c-accent);
  text-decoration: none;
  transition: color var(--transition);
}

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

img, svg, video {
  display: block;
  max-width: 100%;
}

button {
  font-family: inherit;
  font-size: inherit;
  cursor: pointer;
  border: none;
  background: none;
  color: inherit;
}

ul {
  list-style: none;
}

:focus-visible {
  outline: 2px solid var(--c-lime);
  outline-offset: 3px;
}

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

.is-hidden {
  display: none !important;
}

.skip-link {
  position: fixed;
  top: -100px;
  left: var(--space-2);
  z-index: 5000;
  background: var(--c-accent);
  color: var(--c-bg);
  font-weight: 700;
  padding: var(--space-1) var(--space-2);
  border-radius: 0;
  transition: top var(--transition);
}

.skip-link:focus-visible {
  top: var(--space-1);
}

.container {
  width: 100%;
  max-width: var(--container-max);
  margin: 0 auto;
  padding-left: var(--space-4);
  padding-right: var(--space-4);
}

.grid-12 {
  display: grid;
  grid-template-columns: repeat(12, 1fr);
  gap: var(--space-3);
}

.col-span-4 {
  grid-column: span 4;
}

.col-span-6 {
  grid-column: span 6;
}

.col-span-8 {
  grid-column: span 8;
}

.col-span-12 {
  grid-column: span 12;
}

.site-header {
  position: fixed;
  top: 0;
  left: 0;
  bottom: 0;
  width: var(--sidebar-w);
  background-color: var(--c-surface);
  border-right: 1px solid var(--c-border);
  z-index: 2000;
  display: flex;
  flex-direction: column;
}

.progress-track {
  position: fixed;
  top: 4px;
  left: 0;
  height: 2px;
  background-color: var(--c-accent);
  z-index: 4000;
  width: 0%;
  box-shadow: 0 0 8px var(--c-accent);
}

.nav-track {
  padding: var(--space-3);
  border-bottom: 1px solid var(--c-border);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: var(--space-1);
  font-weight: 700;
  font-size: 1.25rem;
  color: var(--c-text);
  letter-spacing: 0.02em;
}

.brand-mark {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  background-color: var(--c-accent);
  color: var(--c-bg);
  font-weight: 700;
  padding: 2px 6px;
  font-size: 1rem;
  border-radius: 0;
}

.brand-name {
  color: var(--c-text);
}

.nav-toggle {
  display: none;
  width: 40px;
  height: 40px;
  position: relative;
  background: transparent;
  border: 1px solid var(--c-border);
  border-radius: 0;
}

.nav-toggle-icon,
.nav-toggle-icon::before,
.nav-toggle-icon::after {
  content: '';
  display: block;
  width: 20px;
  height: 2px;
  background-color: var(--c-text);
  margin: 0 auto;
  transition: transform var(--transition);
}

.nav-toggle-icon {
  position: relative;
}

.nav-toggle-icon::before {
  position: absolute;
  top: -6px;
  left: 0;
}

.nav-toggle-icon::after {
  position: absolute;
  top: 6px;
  left: 0;
}

.nav-toggle[aria-expanded="true"] .nav-toggle-icon {
  background-color: transparent;
}

.nav-toggle[aria-expanded="true"] .nav-toggle-icon::before {
  transform: translateY(6px) rotate(45deg);
}

.nav-toggle[aria-expanded="true"] .nav-toggle-icon::after {
  transform: translateY(-6px) rotate(-45deg);
}

.nav-panel {
  flex: 1;
  display: flex;
  flex-direction: column;
  overflow-y: auto;
}

.nav-links {
  padding: var(--space-2) 0;
}

.nav-link {
  display: flex;
  align-items: baseline;
  gap: var(--space-1);
  padding: 12px var(--space-3);
  color: var(--c-text-dim);
  font-weight: 700;
  font-size: 0.95rem;
  border-left: 3px solid transparent;
  transition: all var(--transition);
  text-decoration: none;
}

.nav-link::before {
  content: attr(data-index);
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--c-accent);
  letter-spacing: 0.1em;
}

.nav-link:hover {
  color: var(--c-text);
  background: rgba(42, 79, 126, 0.25);
  border-left-color: var(--c-border);
}

.nav-link[aria-current="page"] {
  color: var(--c-text);
  border-left-color: var(--c-accent);
  background: linear-gradient(90deg, rgba(255, 107, 53, 0.18), transparent);
}

.nav-link[aria-current="page"]::before {
  color: var(--c-lime);
}

.version-toggle {
  margin-top: auto;
  padding: var(--space-3);
}

.toggle-label {
  display: block;
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.15em;
  color: var(--c-text-dim);
  margin-bottom: var(--space-1);
  font-weight: 700;
}

.toggle-group {
  display: grid;
  grid-template-columns: 1fr 1fr;
  border: 1px solid var(--c-border);
  border-radius: 0;
}

.toggle-btn {
  padding: 10px 12px;
  font-size: 0.9rem;
  font-weight: 700;
  background-color: transparent;
  color: var(--c-text-dim);
  border: none;
  transition: all var(--transition);
}

.toggle-btn + .toggle-btn {
  border-left: 1px solid var(--c-border);
}

.toggle-btn.is-active {
  background-color: var(--c-accent);
  color: var(--c-bg);
}

.site-footer {
  background-color: var(--c-bg);
  border-top: 1px solid var(--c-border);
  padding: var(--space-4) var(--space-3) var(--space-2);
  margin-left: 0;
  position: relative;
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  gap: var(--space-4);
  max-width: var(--container-max);
  margin: 0 auto;
}

.footer-brand .brand {
  margin-bottom: var(--space-2);
}

.footer-desc {
  color: var(--c-text-dim);
  font-size: 0.9rem;
  max-width: 320px;
}

.footer-title {
  color: var(--c-text);
  font-size: 0.9rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  margin-bottom: var(--space-2);
  padding-bottom: var(--space-1);
  border-bottom: 1px solid var(--c-border);
}

.footer-links a,
.footer-contact p {
  display: block;
  color: var(--c-text-dim);
  font-size: 0.9rem;
  line-height: 1.9;
  text-decoration: none;
}

.footer-links a:hover {
  color: var(--c-lime);
}

.contact-label {
  display: block;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--c-border);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.footer-bottom {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  border-top: 1px solid var(--c-border);
  margin-top: var(--space-4);
  padding-top: var(--space-2);
  max-width: var(--container-max);
  margin-left: auto;
  margin-right: auto;
}

.footer-copy,
.footer-icp {
  color: var(--c-text-dim);
  font-size: 0.75rem;
  font-family: var(--font-mono);
}

.footer-icp {
  letter-spacing: 0.05em;
}

.back-top {
  position: fixed;
  bottom: var(--space-3);
  right: var(--space-3);
  z-index: 1500;
  background-color: var(--c-accent);
  color: var(--c-bg);
  font-weight: 700;
  font-size: 0.85rem;
  padding: 10px 16px;
  border: 1px solid var(--c-accent);
  border-radius: 0;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.3);
  transition: background-color var(--transition);
}

.back-top:hover {
  background-color: var(--c-accent-dark);
}

.btn {
  display: inline-block;
  padding: 12px 24px;
  font-weight: 700;
  font-size: 0.95rem;
  text-align: center;
  text-decoration: none;
  border: 1px solid var(--c-border);
  color: var(--c-text);
  background-color: transparent;
  transition: all var(--transition);
  border-radius: 0;
}

.btn:hover {
  border-color: var(--c-text);
  color: var(--c-text);
}

.btn-primary {
  background-color: var(--c-accent);
  border-color: var(--c-accent);
  color: var(--c-bg);
}

.btn-primary:hover {
  background-color: var(--c-accent-dark);
  border-color: var(--c-accent-dark);
  color: var(--c-bg);
}

.card {
  background-color: var(--c-surface);
  border: 1px solid var(--c-border);
  border-radius: 0;
  padding: var(--space-3);
  transition: all var(--transition);
}

.panel {
  background-color: var(--c-surface);
  border: 1px solid var(--c-border);
  border-radius: 0;
  padding: var(--space-4);
}

.tag {
  display: inline-block;
  padding: 4px 10px;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.05em;
  color: var(--c-lime);
  background-color: rgba(57, 255, 20, 0.1);
  border: 1px solid rgba(57, 255, 20, 0.3);
  border-radius: 0;
}

.exhibit-tag {
  display: inline-flex;
  align-items: center;
  gap: var(--space-1);
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.15em;
  color: var(--c-accent);
  border: 1px solid var(--c-accent);
  background-color: transparent;
  padding: 6px 12px;
  text-transform: uppercase;
}

.exhibit-tag::before {
  content: '';
  display: inline-block;
  width: 6px;
  height: 6px;
  background-color: var(--c-lime);
}

.specimen-card {
  background-color: var(--c-surface);
  border: 1px solid var(--c-border);
  border-left-width: 4px;
  border-left-color: var(--c-accent);
  padding: var(--space-3);
  border-radius: 0;
}

.specimen-card .specimen-title {
  font-size: 1.1rem;
  font-weight: 700;
  margin-bottom: var(--space-1);
}

.specimen-card .specimen-meta {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--c-border);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: var(--space-2);
}

.specimen-card .specimen-desc {
  font-size: 0.9rem;
  color: var(--c-text-dim);
  line-height: 1.6;
}

.image-container {
  position: relative;
  width: 100%;
  aspect-ratio: 16 / 9;
  background-color: var(--c-surface);
  border: 1px solid var(--c-border);
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
  color: var(--c-text-dim);
  font-family: var(--font-mono);
  font-size: 0.85rem;
  letter-spacing: 0.05em;
}

.image-container::before {
  content: 'IMAGE';
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(42, 79, 126, 0.3) 1px, transparent 1px),
    linear-gradient(90deg, rgba(42, 79, 126, 0.3) 1px, transparent 1px);
  background-size: 24px 24px;
  display: flex;
  align-items: center;
  justify-content: center;
  letter-spacing: 0.2em;
  font-size: 0.75rem;
  z-index: 1;
}

.image-container img {
  position: relative;
  z-index: 2;
  width: 100%;
  height: 100%;
  object-fit: cover;
}

@media (hover: hover) and (prefers-reduced-motion: no-preference) {
  .card:hover {
    transform: translateY(-2px);
    border-color: var(--c-accent);
  }
}

@media (max-width: 1200px) {
  :root {
    --sidebar-w: 240px;
  }
  .footer-grid {
    grid-template-columns: 1fr 1fr;
  }
}

@media (max-width: 900px) {
  body {
    margin-left: 0;
  }

  .site-header {
    position: sticky;
    top: 0;
    width: 100%;
    height: auto;
    max-height: 100vh;
    flex-direction: column;
    border-right: none;
    border-bottom: 1px solid var(--c-border);
    background-color: var(--c-surface);
  }

  .nav-track {
    display: flex;
    justify-content: space-between;
    align-items: center;
    width: 100%;
    padding: var(--space-2);
    border-bottom: 1px solid var(--c-border);
  }

  .nav-toggle {
    display: flex;
    align-items: center;
    justify-content: center;
    margin-left: auto;
  }

  .nav-panel {
    position: fixed;
    top: var(--header-h);
    left: 0;
    right: 0;
    bottom: 0;
    background-color: var(--c-surface);
    transform: translateX(-100%);
    transition: transform 250ms ease-out;
    padding: var(--space-2);
    overflow-y: auto;
    z-index: 2900;
    flex-direction: column;
  }

  .nav-panel[data-open] {
    transform: translateX(0);
  }

  .nav-links {
    padding: var(--space-2) 0;
  }

  .nav-link {
    padding: 14px var(--space-3);
    font-size: 1rem;
  }

  .version-toggle {
    margin-top: auto;
    padding: var(--space-2);
  }

  .site-footer {
    padding: var(--space-4) var(--space-2) var(--space-2);
  }

  .footer-grid {
    grid-template-columns: 1fr;
    gap: var(--space-3);
  }

  .footer-bottom {
    margin-top: var(--space-3);
  }

  .back-top {
    bottom: var(--space-2);
    right: var(--space-2);
  }

  .container {
    padding-left: var(--space-2);
    padding-right: var(--space-2);
  }

  .grid-12 {
    gap: var(--space-2);
  }

  .col-span-4,
  .col-span-6,
  .col-span-8 {
    grid-column: span 12;
  }

  .progress-track {
    top: 0;
    height: 3px;
  }
}

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