/* ============================================
   青色大脑 CYAN BRAIN — Cyber-Brain Theme
   Electric Cyan + Neural-Circuit Grays
   Synaptic Spark Motifs · Bio-Digital Fusion
   ============================================ */

/* --- CSS Variables --- */
:root {
  /* Accent: Electric Cyan */
  --cyan: #00e5ff;
  --cyan-bright: #00f5ff;
  --cyan-deep: #00838f;
  --cyan-glow: rgba(0, 229, 255, 0.25);
  --cyan-glow-strong: rgba(0, 229, 255, 0.45);

  /* Neural-Circuit Grays */
  --void: #0a0a14;
  --dark: #16162a;
  --dark-mid: #232340;
  --gray-neural: #3a3a52;
  --gray-circuit: #5a5a6a;
  --gray-soft: #8a8a9a;
  --gray-pale: #b0b0be;

  /* Light Tech Background */
  --bg: #f0f3f8;
  --bg-card: #ffffff;
  --bg-alt: #e8ecf2;
  --bg-header: var(--void);

  /* Typography */
  --text: #1a1a2e;
  --text-secondary: #4a4a5e;
  --text-muted: #7a7a8e;
  --text-on-dark: #e0e4ec;
  --font-mono: 'Courier New', 'Source Code Pro', monospace;

  /* UI */
  --radius: 4px;
  --radius-lg: 8px;
  --shadow: 0 2px 12px rgba(0, 0, 0, 0.08);
  --shadow-lg: 0 4px 24px rgba(0, 0, 0, 0.12);
  --shadow-glow: 0 0 20px var(--cyan-glow);
  --max-width: 1120px;
}

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

html { scroll-behavior: smooth; font-size: 16px; }

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Microsoft YaHei', sans-serif;
  color: var(--text);
  background: var(--bg);
  line-height: 1.7;
  min-height: 100vh;
  position: relative;
}

/* Bio-digital body texture: subtle synaptic radial overlays */
body::before {
  content: '';
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 0;
  background:
    radial-gradient(circle at 20% 15%, var(--cyan-glow) 0%, transparent 40%),
    radial-gradient(circle at 80% 30%, rgba(0, 180, 216, 0.12) 0%, transparent 35%),
    radial-gradient(circle at 60% 70%, rgba(0, 229, 255, 0.08) 0%, transparent 35%),
    radial-gradient(circle at 10% 80%, rgba(0, 131, 143, 0.10) 0%, transparent 30%);
}

/* Neural circuit grid lines — very subtle */
body::after {
  content: '';
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 0;
  opacity: 0.03;
  background-image:
    linear-gradient(var(--gray-circuit) 1px, transparent 1px),
    linear-gradient(90deg, var(--gray-circuit) 1px, transparent 1px);
  background-size: 80px 80px;
}

/* --- Header --- */
.site-header {
  background: var(--bg-header);
  border-bottom: 2px solid var(--cyan-deep);
  position: sticky;
  top: 0;
  z-index: 1000;
  box-shadow: 0 2px 16px rgba(0, 0, 0, 0.3);
}

.site-header::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: 0;
  right: 0;
  height: 2px;
  background: linear-gradient(90deg, transparent, var(--cyan-bright), transparent);
  opacity: 0.6;
}

.header-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 20px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 60px;
  position: relative;
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
  color: var(--text-on-dark);
  font-weight: 700;
  font-size: 1.15rem;
  letter-spacing: 0.5px;
  white-space: nowrap;
}

.logo-icon {
  width: 32px;
  height: 32px;
  border-radius: 50%;
  background: radial-gradient(circle at 40% 35%, var(--cyan-bright), var(--cyan-deep));
  box-shadow: 0 0 12px var(--cyan-glow);
  flex-shrink: 0;
}

.logo-text {
  display: flex;
  flex-direction: column;
  line-height: 1.2;
}

.logo-text .cn { font-size: 1.05rem; }
.logo-text .en { font-size: 0.65rem; color: var(--cyan-bright); text-transform: uppercase; letter-spacing: 2px; }

/* Nav */
.main-nav { display: flex; align-items: center; gap: 2px; }

.main-nav a {
  color: var(--gray-pale);
  text-decoration: none;
  padding: 6px 14px;
  border-radius: var(--radius);
  font-size: 0.9rem;
  transition: all 0.2s;
  position: relative;
}

.main-nav a:hover,
.main-nav a.active {
  color: var(--cyan-bright);
  background: rgba(0, 229, 255, 0.08);
  text-shadow: 0 0 8px var(--cyan-glow);
}

/* Nav CTA button */
.nav-cta {
  background: linear-gradient(135deg, var(--cyan-deep), var(--cyan));
  color: var(--void) !important;
  font-weight: 700;
  margin-left: 8px;
  border-radius: var(--radius-lg) !important;
  box-shadow: 0 0 16px var(--cyan-glow);
  transition: all 0.25s !important;
}

.nav-cta:hover {
  box-shadow: 0 0 24px var(--cyan-glow-strong);
  transform: translateY(-1px);
  color: var(--void) !important;
  background: linear-gradient(135deg, var(--cyan-bright), #00f5ff) !important;
}

/* Hamburger */
.hamburger {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: 8px;
  flex-direction: column;
  gap: 5px;
  z-index: 1001;
}

.hamburger span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--cyan-bright);
  transition: all 0.3s;
  border-radius: 1px;
}

.hamburger.open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.hamburger.open span:nth-child(2) { opacity: 0; }
.hamburger.open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* --- Hero --- */
.hero {
  position: relative;
  overflow: hidden;
  min-height: 480px;
  display: flex;
  align-items: center;
  background: var(--void);
  z-index: 1;
}

.hero-bg {
  position: absolute;
  inset: 0;
  background-size: cover;
  background-position: center;
  opacity: 0.5;
  z-index: 0;
}

/* Synaptic spark overlay */
.hero::before {
  content: '';
  position: absolute;
  inset: 0;
  z-index: 1;
  pointer-events: none;
  background:
    radial-gradient(ellipse at 25% 20%, rgba(0, 229, 255, 0.2) 0%, transparent 50%),
    radial-gradient(ellipse at 75% 60%, rgba(0, 131, 143, 0.15) 0%, transparent 40%),
    radial-gradient(ellipse at 50% 80%, rgba(0, 229, 255, 0.08) 0%, transparent 35%);
}

/* Neural circuit lines overlay */
.hero::after {
  content: '';
  position: absolute;
  inset: 0;
  z-index: 1;
  pointer-events: none;
  opacity: 0.06;
  background-image:
    repeating-linear-gradient(0deg, var(--cyan-bright), var(--cyan-bright) 1px, transparent 1px, transparent 40px),
    repeating-linear-gradient(90deg, var(--cyan-bright), var(--cyan-bright) 1px, transparent 1px, transparent 40px);
}

.hero-inner {
  position: relative;
  z-index: 2;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 80px 20px;
  text-align: center;
  color: var(--text-on-dark);
}

.hero h1 {
  font-size: 2.6rem;
  font-weight: 800;
  margin-bottom: 16px;
  background: linear-gradient(180deg, #ffffff 0%, var(--cyan-bright) 50%, var(--cyan-deep) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  filter: drop-shadow(0 0 24px var(--cyan-glow));
}

.hero-subtitle {
  font-size: 1.15rem;
  color: var(--gray-pale);
  max-width: 700px;
  margin: 0 auto 12px;
  line-height: 1.6;
}

.hero-tags {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 8px;
  margin: 20px 0 28px;
}

.tag {
  display: inline-block;
  padding: 4px 14px;
  border-radius: 20px;
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 0.5px;
}

.tag-cyan {
  background: rgba(0, 229, 255, 0.15);
  color: var(--cyan-bright);
  border: 1px solid rgba(0, 229, 255, 0.3);
}

.tag-gray {
  background: rgba(176, 176, 190, 0.12);
  color: var(--gray-pale);
  border: 1px solid rgba(176, 176, 190, 0.2);
}

.tag-dark {
  background: rgba(0, 0, 0, 0.4);
  color: var(--gray-pale);
  border: 1px solid var(--gray-neural);
}

/* Hero CTA */
.btn-hero {
  display: inline-block;
  padding: 14px 40px;
  background: linear-gradient(135deg, var(--cyan-deep), var(--cyan));
  color: var(--void);
  text-decoration: none;
  font-weight: 700;
  font-size: 1.05rem;
  border-radius: var(--radius-lg);
  box-shadow: 0 0 24px var(--cyan-glow), 0 4px 16px rgba(0,0,0,0.3);
  transition: all 0.3s;
  border: none;
  cursor: pointer;
}

.btn-hero:hover {
  box-shadow: 0 0 40px var(--cyan-glow-strong), 0 6px 24px rgba(0,0,0,0.4);
  transform: translateY(-2px);
}

/* --- Page Hero (sub-pages) --- */
.page-hero {
  background: var(--void);
  position: relative;
  overflow: hidden;
  z-index: 1;
}

.page-hero::before {
  content: '';
  position: absolute;
  inset: 0;
  z-index: 1;
  pointer-events: none;
  background:
    radial-gradient(ellipse at 30% 50%, rgba(0, 229, 255, 0.12) 0%, transparent 60%),
    radial-gradient(ellipse at 70% 50%, rgba(0, 131, 143, 0.08) 0%, transparent 50%);
}

.page-hero-inner {
  position: relative;
  z-index: 2;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 60px 20px;
  text-align: center;
  color: var(--text-on-dark);
}

.page-hero h1 {
  font-size: 2rem;
  font-weight: 800;
  background: linear-gradient(180deg, #ffffff, var(--cyan-bright));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.page-hero p {
  color: var(--gray-pale);
  margin-top: 10px;
  font-size: 0.95rem;
}

/* Per-page hero bg classes */
.hero-home .hero-bg { background-image: url('../img/header.jpg'); }
.hero-guide .hero-bg { background-image: url('../img/screenshot-01.jpg'); }
.hero-characters .hero-bg { background-image: url('../img/screenshot-02.jpg'); }
.hero-story .hero-bg { background-image: url('../img/screenshot-03.jpg'); }
.hero-faq .hero-bg { background-image: url('../img/header.jpg'); }

/* --- Section styles --- */
section { position: relative; z-index: 1; }

.section { padding: 64px 20px; }
.section-alt { background: var(--bg-alt); }

.section-inner {
  max-width: var(--max-width);
  margin: 0 auto;
}

.section-title {
  font-size: 1.8rem;
  font-weight: 800;
  text-align: center;
  margin-bottom: 10px;
  color: var(--text);
}

.section-subtitle {
  text-align: center;
  color: var(--text-secondary);
  margin-bottom: 40px;
  font-size: 0.95rem;
}

/* Synaptic accent line under section titles */
.section-title::after {
  content: '';
  display: block;
  width: 60px;
  height: 3px;
  margin: 14px auto 0;
  background: linear-gradient(90deg, var(--cyan-deep), var(--cyan-bright));
  border-radius: 2px;
  box-shadow: 0 0 10px var(--cyan-glow);
}

/* --- Cards --- */
.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 24px;
}

.card {
  background: var(--bg-card);
  border-radius: var(--radius-lg);
  padding: 28px 24px;
  box-shadow: var(--shadow);
  transition: all 0.3s;
  border: 1px solid transparent;
  position: relative;
  overflow: hidden;
}

/* Neural-circuit left border accent */
.card::before {
  content: '';
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 3px;
  background: var(--gray-circuit);
  transition: all 0.3s;
}

.card:hover {
  box-shadow: var(--shadow-lg), var(--shadow-glow);
  border-color: rgba(0, 229, 255, 0.2);
}

.card:hover::before {
  background: linear-gradient(180deg, var(--cyan-deep), var(--cyan-bright), var(--cyan-deep));
  box-shadow: 0 0 12px var(--cyan-glow);
}

.card-icon {
  font-size: 2rem;
  margin-bottom: 12px;
  display: block;
}

.card h3 {
  font-size: 1.1rem;
  font-weight: 700;
  margin-bottom: 8px;
  color: var(--text);
}

.card p {
  color: var(--text-secondary);
  font-size: 0.9rem;
  line-height: 1.6;
}

/* --- Feature Cards --- */
.feature-card {
  background: var(--bg-card);
  border-radius: var(--radius-lg);
  padding: 24px;
  box-shadow: var(--shadow);
  border-left: 4px solid var(--gray-circuit);
  transition: all 0.3s;
}

.feature-card:hover {
  border-left-color: var(--cyan-bright);
  box-shadow: var(--shadow-lg), 0 0 16px var(--cyan-glow);
}

.feature-card h3 {
  font-size: 1.05rem;
  font-weight: 700;
  margin-bottom: 6px;
}

.feature-card p {
  color: var(--text-secondary);
  font-size: 0.88rem;
}

/* --- Info Cards --- */
.info-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
  gap: 16px;
}

.info-card {
  background: var(--bg-card);
  border-radius: var(--radius-lg);
  padding: 20px;
  box-shadow: var(--shadow);
  border-top: 3px solid transparent;
  transition: all 0.3s;
}

.info-card:hover {
  border-top-color: var(--cyan-bright);
  box-shadow: var(--shadow-lg);
}

.info-label {
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 1px;
  color: var(--text-muted);
  margin-bottom: 6px;
  font-weight: 600;
}

.info-value {
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--text);
}

.info-value.cyan { color: var(--cyan-deep); }

/* --- Story Blocks --- */
.story-block {
  padding: 24px;
  margin-bottom: 20px;
  background: var(--bg-card);
  border-radius: var(--radius-lg);
  border-left: 4px solid var(--gray-neural);
  box-shadow: var(--shadow);
  transition: all 0.3s;
}

.story-block:hover {
  border-left-color: var(--cyan-bright);
  box-shadow: var(--shadow-lg);
}

.story-block h3 {
  font-size: 1.15rem;
  font-weight: 700;
  margin-bottom: 10px;
  color: var(--text);
}

.story-block p {
  color: var(--text-secondary);
  line-height: 1.7;
}

.story-chapter {
  display: inline-block;
  background: var(--void);
  color: var(--cyan-bright);
  padding: 2px 12px;
  border-radius: 20px;
  font-size: 0.75rem;
  font-weight: 600;
  margin-bottom: 10px;
}

/* --- Character Cards --- */
.char-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 24px;
}

.char-card {
  background: var(--bg-card);
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow);
  transition: all 0.3s;
  border: 1px solid transparent;
}

.char-card:hover {
  box-shadow: var(--shadow-lg), 0 0 20px var(--cyan-glow);
  border-color: rgba(0, 229, 255, 0.25);
}

.char-card-header {
  background: var(--void);
  padding: 20px;
  text-align: center;
  position: relative;
  overflow: hidden;
}

.char-card-header::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  height: 2px;
  background: linear-gradient(90deg, transparent, var(--cyan-bright), transparent);
}

.char-avatar {
  width: 80px;
  height: 80px;
  border-radius: 50%;
  margin: 0 auto 10px;
  background: radial-gradient(circle at 40% 35%, var(--cyan-bright), var(--cyan-deep));
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 2.4rem;
  box-shadow: 0 0 16px var(--cyan-glow);
}

.char-card-header h3 {
  color: var(--text-on-dark);
  font-size: 1.1rem;
  margin-bottom: 4px;
}

.char-role {
  color: var(--cyan-bright);
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 0.5px;
}

.char-card-body {
  padding: 20px;
}

.char-card-body p {
  color: var(--text-secondary);
  font-size: 0.88rem;
  line-height: 1.6;
}

.char-traits {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin-top: 12px;
}

.char-trait {
  padding: 2px 10px;
  border-radius: 14px;
  font-size: 0.72rem;
  font-weight: 600;
  background: rgba(0, 229, 255, 0.08);
  color: var(--cyan-deep);
  border: 1px solid rgba(0, 229, 255, 0.2);
}

/* --- Guide Steps --- */
.guide-steps {
  display: flex;
  flex-direction: column;
  gap: 20px;
  counter-reset: step;
}

.guide-step {
  background: var(--bg-card);
  padding: 24px 24px 24px 80px;
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow);
  position: relative;
  transition: all 0.3s;
  border: 1px solid transparent;
}

.guide-step:hover {
  border-color: rgba(0, 229, 255, 0.2);
  box-shadow: var(--shadow-lg);
}

.guide-step::before {
  counter-increment: step;
  content: counter(step);
  position: absolute;
  left: 20px;
  top: 24px;
  width: 42px;
  height: 42px;
  border-radius: 50%;
  background: var(--void);
  color: var(--cyan-bright);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 800;
  font-size: 1.1rem;
  border: 2px solid var(--cyan-bright);
  box-shadow: 0 0 12px var(--cyan-glow);
}

.guide-step h3 {
  font-size: 1.05rem;
  font-weight: 700;
  margin-bottom: 6px;
}

.guide-step p { color: var(--text-secondary); font-size: 0.9rem; }

/* Tip box */
.tip-box {
  background: rgba(0, 229, 255, 0.05);
  border-left: 4px solid var(--cyan-bright);
  border-radius: var(--radius);
  padding: 16px 20px;
  margin: 24px 0;
}

.tip-box p { color: var(--text-secondary); font-size: 0.9rem; margin: 0; }

/* --- Gallery --- */
.gallery {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 16px;
}

.gallery-item {
  border-radius: var(--radius-lg);
  overflow: hidden;
  cursor: pointer;
  position: relative;
  box-shadow: var(--shadow);
  transition: all 0.3s;
  aspect-ratio: 16/9;
  background: var(--void);
}

.gallery-item img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
  transition: all 0.3s;
}

.gallery-item:hover {
  box-shadow: 0 0 24px var(--cyan-glow), var(--shadow-lg);
}

.gallery-item:hover img {
  transform: scale(1.05);
  opacity: 0.9;
}

.gallery-item::after {
  content: '🔍';
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  font-size: 2rem;
  opacity: 0;
  transition: opacity 0.3s;
  pointer-events: none;
  z-index: 2;
}

.gallery-item:hover::after { opacity: 1; }

/* --- FAQ Accordion --- */
.faq-list { display: flex; flex-direction: column; gap: 8px; }

.faq-item {
  background: var(--bg-card);
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow);
  border: 1px solid transparent;
  transition: all 0.3s;
}

.faq-item:hover {
  border-color: rgba(0, 229, 255, 0.15);
}

.faq-question {
  width: 100%;
  background: none;
  border: none;
  padding: 18px 20px;
  text-align: left;
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--text);
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 16px;
  line-height: 1.4;
}

.faq-question::after {
  content: '+';
  font-size: 1.4rem;
  font-weight: 300;
  color: var(--cyan-deep);
  flex-shrink: 0;
  transition: transform 0.3s;
}

.faq-item.open .faq-question::after {
  content: '−';
  transform: rotate(0);
}

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.35s ease, padding 0.35s ease;
}

.faq-item.open .faq-answer {
  max-height: 300px;
  padding: 0 20px 20px;
}

.faq-answer p {
  color: var(--text-secondary);
  font-size: 0.9rem;
  line-height: 1.6;
}

/* --- CTA Banner --- */
.cta-banner {
  background: var(--void);
  padding: 50px 20px;
  text-align: center;
  position: relative;
  overflow: hidden;
}

.cta-banner::before {
  content: '';
  position: absolute;
  inset: 0;
  background:
    radial-gradient(ellipse at center, rgba(0, 229, 255, 0.12) 0%, transparent 60%);
  pointer-events: none;
}

.cta-banner h2 {
  color: var(--text-on-dark);
  font-size: 1.6rem;
  margin-bottom: 12px;
  position: relative;
  z-index: 1;
}

.cta-banner p {
  color: var(--gray-pale);
  margin-bottom: 24px;
  position: relative;
  z-index: 1;
  font-size: 0.95rem;
}

/* --- Breadcrumbs --- */
.breadcrumbs {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 16px 20px 0;
  font-size: 0.82rem;
  color: var(--text-muted);
}

.breadcrumbs a {
  color: var(--cyan-deep);
  text-decoration: none;
}

.breadcrumbs a:hover { text-decoration: underline; }

/* --- Stats Row --- */
.stats-row {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 32px;
  margin: 32px 0;
}

.stat-item { text-align: center; }

.stat-value {
  font-size: 2rem;
  font-weight: 800;
  color: var(--cyan-deep);
  text-shadow: 0 0 10px var(--cyan-glow);
}

.stat-label {
  font-size: 0.8rem;
  color: var(--text-muted);
  margin-top: 4px;
}

/* --- Tables --- */
.info-table {
  width: 100%;
  border-collapse: collapse;
  background: var(--bg-card);
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow);
}

.info-table th, .info-table td {
  padding: 12px 16px;
  text-align: left;
  border-bottom: 1px solid var(--bg-alt);
}

.info-table th {
  background: var(--void);
  color: var(--cyan-bright);
  font-weight: 600;
  font-size: 0.85rem;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.info-table td { color: var(--text-secondary); font-size: 0.9rem; }
.info-table tr:last-child td { border-bottom: none; }

/* --- Download Card --- */
.download-card {
  background: var(--bg-card);
  border: 2px solid rgba(0, 229, 255, 0.2);
  border-radius: var(--radius-lg);
  padding: 32px;
  text-align: center;
  box-shadow: var(--shadow-lg);
  max-width: 500px;
  margin: 0 auto;
}

.download-card h3 {
  font-size: 1.3rem;
  margin-bottom: 8px;
}

.download-card .version {
  color: var(--cyan-deep);
  font-weight: 600;
  margin-bottom: 16px;
}

/* --- Utilities --- */
.text-center { text-align: center; }
.intro-text { max-width: 800px; margin: 0 auto; text-align: center; color: var(--text-secondary); line-height: 1.8; }
.mt-1 { margin-top: 8px; }
.mt-2 { margin-top: 16px; }
.mt-3 { margin-top: 24px; }
.mt-4 { margin-top: 32px; }
.mb-1 { margin-bottom: 8px; }
.mb-2 { margin-bottom: 16px; }
.mb-3 { margin-bottom: 24px; }
.pb-0 { padding-bottom: 0; }

/* --- Synaptic Divider --- */
.syn-divider {
  height: 4px;
  background: linear-gradient(90deg, transparent, var(--cyan-deep), var(--cyan-bright), var(--cyan-deep), transparent);
  border: none;
  margin: 40px 0;
  border-radius: 2px;
  box-shadow: 0 0 10px var(--cyan-glow);
}

/* --- Lightbox --- */
.lightbox {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(10, 10, 20, 0.95);
  z-index: 2000;
  align-items: center;
  justify-content: center;
  cursor: pointer;
}

.lightbox.open { display: flex; }

.lightbox img {
  max-width: 90vw;
  max-height: 85vh;
  border-radius: var(--radius-lg);
  box-shadow: 0 0 40px var(--cyan-glow);
}

.lightbox-close {
  position: absolute;
  top: 20px;
  right: 30px;
  background: none;
  border: none;
  color: var(--cyan-bright);
  font-size: 2rem;
  cursor: pointer;
  z-index: 2001;
}

/* --- Footer --- */
.site-footer {
  background: var(--void);
  padding: 24px 20px;
  text-align: center;
  border-top: 1px solid var(--dark-mid);
}

.site-footer p {
  color: var(--gray-soft);
  font-size: 0.8rem;
}

/* --- Responsive --- */
@media (max-width: 768px) {
  .main-nav {
    position: fixed;
    top: 0;
    right: -100%;
    width: 260px;
    height: 100vh;
    background: var(--void);
    flex-direction: column;
    padding: 80px 24px 24px;
    gap: 4px;
    transition: right 0.3s;
    z-index: 999;
    box-shadow: -4px 0 24px rgba(0,0,0,0.5);
  }

  .main-nav.open { right: 0; }

  .main-nav a {
    display: block;
    padding: 12px 16px;
    font-size: 1rem;
  }

  .nav-cta { margin-left: 0; text-align: center; }

  .hamburger { display: flex; }

  .hero h1 { font-size: 1.8rem; }
  .hero-inner { padding: 60px 16px; }
  .hero { min-height: 380px; }

  .card-grid { grid-template-columns: 1fr; }
  .info-grid { grid-template-columns: 1fr 1fr; }
  .char-grid { grid-template-columns: 1fr; }
  .gallery { grid-template-columns: 1fr; }
  .stats-row { gap: 20px; }
  .stat-value { font-size: 1.5rem; }

  .section-title { font-size: 1.4rem; }
  .section { padding: 40px 16px; }

  .guide-step { padding: 20px 16px 20px 64px; }
  .guide-step::before { left: 14px; top: 20px; width: 36px; height: 36px; font-size: 0.95rem; }

  .header-inner { height: 52px; }
}

@media (max-width: 480px) {
  .hero h1 { font-size: 1.5rem; }
  .hero-subtitle { font-size: 0.95rem; }
  .hero { min-height: 320px; }
  .btn-hero { padding: 12px 28px; font-size: 0.95rem; }
  .info-grid { grid-template-columns: 1fr; }
  .page-hero h1 { font-size: 1.5rem; }
  .stats-row { flex-direction: column; gap: 16px; align-items: center; }
}