/* ============================================
   CoMManD — Dark Sci-fi Theme
   ============================================ */

:root {
  --bg-primary: #070b14;
  --bg-secondary: #0c1220;
  --bg-card: rgba(15, 23, 42, 0.7);
  --bg-card-hover: rgba(20, 30, 55, 0.85);
  --accent-blue: #38bdf8;
  --accent-purple: #818cf8;
  --accent-cyan: #22d3ee;
  --accent-glow: rgba(56, 189, 248, 0.15);
  --text-primary: #e2e8f0;
  --text-secondary: #94a3b8;
  --text-muted: #64748b;
  --border: rgba(56, 189, 248, 0.12);
  --border-bright: rgba(56, 189, 248, 0.3);
  --font-display: 'Orbitron', sans-serif;
  --font-body: 'Rajdhani', 'Noto Sans SC', sans-serif;
  --font-zh: 'Noto Sans SC', sans-serif;
  --max-width: 1100px;
  --section-padding: 6rem 0;
}

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

html {
  scroll-behavior: smooth;
  scrollbar-width: thin;
  scrollbar-color: var(--accent-blue) var(--bg-primary);
}

body {
  background: var(--bg-primary);
  color: var(--text-primary);
  font-family: var(--font-body);
  font-weight: 400;
  line-height: 1.7;
  overflow-x: hidden;
}

[data-lang="zh"] body,
[data-lang="zh"] .abstract-text,
[data-lang="zh"] .section-desc,
[data-lang="zh"] p {
  font-family: var(--font-zh);
}

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

.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 2rem;
}

/* ============================================
   Language Toggle
   ============================================ */
.lang-toggle {
  position: fixed;
  top: 1.5rem;
  right: 1.5rem;
  z-index: 1000;
  background: var(--bg-card);
  border: 1px solid var(--border-bright);
  color: var(--accent-cyan);
  font-family: var(--font-display);
  font-size: 0.75rem;
  letter-spacing: 0.1em;
  padding: 0.5rem 1rem;
  cursor: pointer;
  transition: all 0.3s;
  backdrop-filter: blur(12px);
}

.lang-toggle:hover {
  background: var(--accent-blue);
  color: var(--bg-primary);
  border-color: var(--accent-blue);
}

/* ============================================
   Side Navigation
   ============================================ */
.side-nav {
  position: fixed;
  right: 1.5rem;
  top: 50%;
  transform: translateY(-50%);
  z-index: 900;
  display: flex;
  flex-direction: column;
  gap: 1.2rem;
}

.nav-dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--text-muted);
  border: none;
  cursor: pointer;
  transition: all 0.3s;
  position: relative;
  text-decoration: none;
}

.nav-dot.active {
  background: var(--accent-blue);
  box-shadow: 0 0 10px var(--accent-blue);
}

.nav-label {
  position: absolute;
  right: 20px;
  top: 50%;
  transform: translateY(-50%);
  white-space: nowrap;
  font-size: 0.7rem;
  font-family: var(--font-display);
  letter-spacing: 0.08em;
  color: var(--text-secondary);
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.2s;
}

.nav-dot:hover .nav-label {
  opacity: 1;
}

/* ============================================
   Hero
   ============================================ */
.hero {
  position: relative;
  min-height: 100vh;
  display: flex;
  align-items: center;
  padding: 4rem 0;
  overflow: hidden;
}

.hero-bg {
  position: absolute;
  inset: 0;
  background:
    radial-gradient(ellipse 80% 60% at 50% 0%, rgba(56,189,248,0.08) 0%, transparent 60%),
    radial-gradient(ellipse 60% 50% at 80% 80%, rgba(129,140,248,0.06) 0%, transparent 50%);
}

.hero .container {
  position: relative;
  text-align: center;
}

.hero-badge {
  display: inline-block;
  padding: 0.3rem 1.2rem;
  border: 1px solid var(--border-bright);
  font-family: var(--font-display);
  font-size: 0.7rem;
  letter-spacing: 0.2em;
  color: var(--accent-cyan);
  margin-bottom: 2rem;
  animation: fadeInDown 0.8s ease-out;
}

.hero-title {
  margin-bottom: 1.5rem;
  animation: fadeInDown 0.8s ease-out 0.1s both;
}

.title-accent {
  font-family: var(--font-display);
  font-size: clamp(3rem, 8vw, 5.5rem);
  font-weight: 900;
  letter-spacing: 0.15em;
  background: linear-gradient(135deg, var(--accent-blue), var(--accent-purple), var(--accent-cyan));
  background-size: 200% 200%;
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  animation: gradientShift 6s ease infinite;
  filter: drop-shadow(0 0 30px rgba(56,189,248,0.2));
}

.hero-subtitle {
  font-size: clamp(1rem, 2.2vw, 1.25rem);
  color: var(--text-secondary);
  max-width: 800px;
  margin: 0 auto 1.5rem;
  line-height: 1.8;
  animation: fadeInUp 0.8s ease-out 0.2s both;
}

.hero-expand {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 0.3rem 0.6rem;
  margin-bottom: 3.5rem;
  animation: fadeInUp 0.8s ease-out 0.3s both;
}

.expand-letter {
  font-size: 0.85rem;
  color: var(--text-muted);
  letter-spacing: 0.02em;
}

.expand-letter b {
  color: var(--accent-cyan);
  font-weight: 700;
  font-size: 1rem;
}

/* Abstract Card */
.abstract-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  padding: 2.5rem;
  margin: 0 auto 4rem;
  max-width: 900px;
  text-align: left;
  backdrop-filter: blur(8px);
  animation: fadeInUp 0.8s ease-out 0.4s both;
}

.section-label {
  font-family: var(--font-display);
  font-size: 0.75rem;
  letter-spacing: 0.2em;
  color: var(--accent-blue);
  text-transform: uppercase;
  margin-bottom: 1rem;
}

.abstract-text {
  font-size: 0.95rem;
  color: var(--text-secondary);
  line-height: 1.9;
}

/* Video */
.video-section {
  max-width: 900px;
  margin: 0 auto;
  animation: fadeInUp 0.8s ease-out 0.5s both;
}

.video-wrapper {
  position: relative;
  aspect-ratio: 16/9;
  background: var(--bg-card);
  border: 1px solid var(--border);
  overflow: hidden;
}

.video-wrapper video {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

/* ============================================
   Sections
   ============================================ */
.section {
  padding: var(--section-padding);
  position: relative;
}

.section-alt {
  background: var(--bg-secondary);
}

.section-title {
  font-family: var(--font-display);
  font-size: clamp(1.5rem, 4vw, 2.2rem);
  font-weight: 700;
  letter-spacing: 0.1em;
  text-align: center;
  margin-bottom: 1rem;
  background: linear-gradient(135deg, var(--accent-blue), var(--accent-purple));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.section-desc {
  text-align: center;
  color: var(--text-secondary);
  max-width: 800px;
  margin: 0 auto 3rem;
  font-size: 0.95rem;
  line-height: 1.8;
}

/* ============================================
   Framework
   ============================================ */
.framework-img-wrapper {
  margin: 0 auto 3.5rem;
  max-width: 950px;
  border: 1px solid var(--border);
  background: rgba(255,255,255,0.03);
  padding: 1.5rem;
  transition: border-color 0.3s;
}

.framework-img-wrapper:hover {
  border-color: var(--border-bright);
}

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

.modules-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.5rem;
}

.module-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  padding: 2rem;
  transition: all 0.3s;
}

.module-card:hover {
  border-color: var(--accent-blue);
  background: var(--bg-card-hover);
  transform: translateY(-3px);
  box-shadow: 0 8px 30px rgba(56,189,248,0.08);
}

.module-card h3 {
  font-family: var(--font-display);
  font-size: 0.85rem;
  letter-spacing: 0.08em;
  color: var(--accent-cyan);
  margin-bottom: 0.8rem;
}

.module-card p {
  font-size: 0.85rem;
  color: var(--text-secondary);
  line-height: 1.7;
}

/* ============================================
   Maps Gallery
   ============================================ */
.map-group-title {
  font-family: var(--font-display);
  font-size: 0.8rem;
  letter-spacing: 0.15em;
  color: var(--accent-blue);
  text-transform: uppercase;
  margin-bottom: 0.4rem;
  padding-left: 0.5rem;
  border-left: 3px solid var(--accent-blue);
}

.map-size-label {
  font-family: var(--font-display);
  font-size: 0.7rem;
  letter-spacing: 0.1em;
  color: var(--text-muted);
  margin-bottom: 1.2rem;
  padding-left: 0.9rem;
}

.maps-grid {
  display: grid;
  gap: 1.5rem;
  margin-bottom: 3rem;
}

.maps-3 {
  grid-template-columns: repeat(3, 1fr);
}

.map-card {
  position: relative;
  overflow: hidden;
  border: 1px solid var(--border);
  background: var(--bg-card);
  aspect-ratio: 1;
  transition: all 0.4s;
}

.map-card:hover {
  border-color: var(--accent-blue);
  box-shadow: 0 0 25px rgba(56,189,248,0.1);
  transform: scale(1.02);
}

.map-card img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
  transition: transform 0.5s;
}

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

/* ============================================
   Results
   ============================================ */
.results-img-wrapper {
  margin: 0 auto 3.5rem;
  max-width: 950px;
  border: 1px solid var(--border);
  background: rgba(255,255,255,0.03);
  padding: 1.5rem;
  transition: border-color 0.3s;
}

.results-img-wrapper:hover {
  border-color: var(--border-bright);
}

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

.findings-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1.5rem;
}

.finding-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  padding: 2rem;
  position: relative;
  transition: all 0.3s;
}

.finding-card:hover {
  border-color: var(--accent-purple);
  background: var(--bg-card-hover);
}

.finding-num {
  font-family: var(--font-display);
  font-size: 2.5rem;
  font-weight: 900;
  color: rgba(56,189,248,0.1);
  position: absolute;
  top: 0.8rem;
  right: 1.2rem;
  line-height: 1;
}

.finding-card h3 {
  font-family: var(--font-display);
  font-size: 0.8rem;
  letter-spacing: 0.08em;
  color: var(--accent-cyan);
  margin-bottom: 0.8rem;
}

.finding-card p {
  font-size: 0.85rem;
  color: var(--text-secondary);
  line-height: 1.7;
}

/* ============================================
   Citation
   ============================================ */
.bibtex-wrapper {
  position: relative;
  max-width: 750px;
  margin: 0 auto;
  background: var(--bg-card);
  border: 1px solid var(--border);
  padding: 2rem;
  overflow-x: auto;
}

.bibtex-code {
  font-family: 'Courier New', monospace;
  font-size: 0.82rem;
  color: var(--text-secondary);
  line-height: 1.8;
  white-space: pre;
}

.copy-btn {
  position: absolute;
  top: 1rem;
  right: 1rem;
  background: transparent;
  border: 1px solid var(--border-bright);
  color: var(--accent-cyan);
  font-family: var(--font-display);
  font-size: 0.65rem;
  letter-spacing: 0.1em;
  padding: 0.35rem 0.8rem;
  cursor: pointer;
  transition: all 0.3s;
}

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

/* ============================================
   Footer
   ============================================ */
.footer {
  text-align: center;
  padding: 2rem;
  color: var(--text-muted);
  font-size: 0.8rem;
  border-top: 1px solid var(--border);
}

/* ============================================
   Scroll to Top
   ============================================ */
.scroll-top {
  position: fixed;
  bottom: 2rem;
  right: 1.5rem;
  z-index: 900;
  width: 38px;
  height: 38px;
  background: var(--bg-card);
  border: 1px solid var(--border-bright);
  color: var(--accent-cyan);
  font-size: 1.1rem;
  cursor: pointer;
  opacity: 0;
  pointer-events: none;
  transition: all 0.3s;
  display: flex;
  align-items: center;
  justify-content: center;
  backdrop-filter: blur(8px);
}

.scroll-top.visible {
  opacity: 1;
  pointer-events: all;
}

.scroll-top:hover {
  background: var(--accent-blue);
  color: var(--bg-primary);
}

/* ============================================
   Animations
   ============================================ */
@keyframes fadeInDown {
  from { opacity: 0; transform: translateY(-20px); }
  to { opacity: 1; transform: translateY(0); }
}

@keyframes fadeInUp {
  from { opacity: 0; transform: translateY(20px); }
  to { opacity: 1; transform: translateY(0); }
}

@keyframes gradientShift {
  0%, 100% { background-position: 0% 50%; }
  50% { background-position: 100% 50%; }
}

/* Scroll reveal */
.reveal {
  opacity: 0;
  transform: translateY(30px);
  transition: all 0.7s ease-out;
}

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

/* ============================================
   Responsive
   ============================================ */
@media (max-width: 768px) {
  :root { --section-padding: 4rem 0; }

  .side-nav { display: none; }

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

  .maps-3 {
    grid-template-columns: repeat(2, 1fr);
  }

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

  .abstract-card {
    padding: 1.5rem;
  }

  .hero-expand {
    padding: 0 1rem;
  }
}

@media (max-width: 480px) {
  .maps-3 {
    grid-template-columns: 1fr;
  }

  .lang-toggle {
    top: 0.8rem;
    right: 0.8rem;
  }
}