/* ═══════════════════════════════════════════
   TopHat.fun — The Grand Cabinet of Curiosities
   Dark elegant theme with blue accents & glassmorphism
   ═══════════════════════════════════════════ */

/* ── CSS Custom Properties ── */
:root {
  --bg-primary: #0a0a1a;
  --bg-secondary: #0f0f2a;
  --bg-card: rgba(255, 255, 255, 0.03);
  --bg-card-hover: rgba(255, 255, 255, 0.06);
  --glass: rgba(255, 255, 255, 0.05);
  --glass-border: rgba(255, 255, 255, 0.08);
  --text-primary: #e8e8f0;
  --text-secondary: #9898b0;
  --text-muted: #6a6a82;
  --accent: #3b82f6;
  --accent-light: #60a5fa;
  --accent-glow: rgba(59, 130, 246, 0.3);
  --accent-subtle: rgba(59, 130, 246, 0.1);
  --purple: #8b5cf6;
  --purple-subtle: rgba(139, 92, 246, 0.1);
  --gold: #f59e0b;
  --gold-subtle: rgba(245, 158, 11, 0.1);
  --radius: 16px;
  --radius-sm: 10px;
  --radius-xs: 6px;
  --shadow: 0 4px 24px rgba(0, 0, 0, 0.3);
  --shadow-glow: 0 0 40px var(--accent-glow);
  --transition: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  --font-display: 'Playfair Display', Georgia, serif;
  --font-body: 'Inter', -apple-system, sans-serif;
  --font-mono: 'JetBrains Mono', monospace;
}

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: 80px;
}

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

/* ── Particle Background ── */
#particles {
  position: fixed;
  top: 0; left: 0;
  width: 100%; height: 100%;
  z-index: 0;
  pointer-events: none;
}

/* ── Navigation ── */
.nav {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 100;
  padding: 0 2rem;
  transition: var(--transition);
}

.nav.scrolled {
  background: rgba(10, 10, 26, 0.85);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--glass-border);
}

.nav-inner {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 72px;
}

.nav-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
  color: var(--text-primary);
}

.logo-icon { width: 36px; height: 36px; }

.logo-text {
  font-family: var(--font-display);
  font-size: 1.25rem;
  font-weight: 700;
  letter-spacing: -0.02em;
}

.logo-dot { color: var(--accent); }

.nav-links {
  display: flex;
  list-style: none;
  gap: 0.25rem;
}

.nav-links a {
  display: block;
  padding: 0.5rem 1rem;
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 0.875rem;
  font-weight: 500;
  border-radius: var(--radius-xs);
  transition: var(--transition);
  position: relative;
}

.nav-links a:hover,
.nav-links a.active {
  color: var(--accent-light);
  background: var(--accent-subtle);
}

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 8px;
}

.nav-toggle span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--text-primary);
  border-radius: 2px;
  transition: var(--transition);
}

/* ── Hero Section ── */
.hero {
  position: relative;
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 6rem 2rem 4rem;
  z-index: 1;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  top: -30%;
  left: -10%;
  width: 60%;
  height: 80%;
  background: radial-gradient(ellipse, var(--accent-subtle) 0%, transparent 70%);
  pointer-events: none;
}

.hero::after {
  content: '';
  position: absolute;
  bottom: -20%;
  right: -10%;
  width: 50%;
  height: 60%;
  background: radial-gradient(ellipse, var(--purple-subtle) 0%, transparent 70%);
  pointer-events: none;
}

.hero-content {
  position: relative;
  text-align: center;
  max-width: 720px;
  z-index: 2;
}

.hero-badge {
  display: inline-block;
  padding: 0.4rem 1.25rem;
  background: var(--accent-subtle);
  border: 1px solid var(--glass-border);
  border-radius: 100px;
  font-size: 0.8rem;
  font-weight: 500;
  color: var(--accent-light);
  letter-spacing: 0.1em;
  text-transform: uppercase;
  margin-bottom: 2rem;
  animation: fadeInDown 0.8s ease-out;
}

.hero-title {
  font-family: var(--font-display);
  font-size: clamp(2.5rem, 6vw, 4.5rem);
  font-weight: 900;
  line-height: 1.1;
  margin-bottom: 1.5rem;
  letter-spacing: -0.03em;
}

.title-line {
  display: block;
  animation: fadeInUp 0.8s ease-out both;
}

.title-line:nth-child(1) { animation-delay: 0.2s; }
.title-line:nth-child(2) { animation-delay: 0.4s; }
.title-line:nth-child(3) { animation-delay: 0.6s; }

.accent { color: var(--accent); }

.hero-subtitle {
  font-size: 1.15rem;
  color: var(--text-secondary);
  margin-bottom: 2.5rem;
  animation: fadeInUp 0.8s ease-out 0.8s both;
}

.hero-actions {
  display: flex;
  gap: 1rem;
  justify-content: center;
  flex-wrap: wrap;
  animation: fadeInUp 0.8s ease-out 1s both;
}

.hero-scroll-hint {
  position: absolute;
  bottom: -3rem;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.5rem;
  color: var(--text-muted);
  font-size: 0.75rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  animation: fadeIn 1s ease-out 1.5s both;
}

.scroll-arrow {
  width: 1px;
  height: 40px;
  background: linear-gradient(to bottom, var(--accent), transparent);
  animation: scrollPulse 2s ease-in-out infinite;
}

/* ── Floating Cards ── */
.hero-decoration {
  position: absolute;
  inset: 0;
  pointer-events: none;
  z-index: 2;
}

.floating-card {
  position: absolute;
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 0.6rem 1rem;
  background: var(--glass);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-sm);
  font-size: 0.8rem;
  color: var(--text-secondary);
  animation: float 6s ease-in-out infinite;
}

.card-icon { font-size: 1.1rem; }

.card-1 { top: 20%; left: 5%; animation-delay: 0s; }
.card-2 { top: 30%; right: 5%; animation-delay: 2s; }
.card-3 { bottom: 25%; left: 8%; animation-delay: 4s; }

/* ── Sections ── */
.section {
  position: relative;
  z-index: 1;
  padding: 6rem 2rem;
}

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

.section-header {
  text-align: center;
  max-width: 600px;
  margin: 0 auto 4rem;
}

.section-tag {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 500;
  color: var(--accent);
  letter-spacing: 0.15em;
  text-transform: uppercase;
  margin-bottom: 1rem;
  padding: 0.3rem 0.75rem;
  background: var(--accent-subtle);
  border-radius: var(--radius-xs);
}

.section-title {
  font-family: var(--font-display);
  font-size: clamp(2rem, 4vw, 3rem);
  font-weight: 700;
  margin-bottom: 0.75rem;
  letter-spacing: -0.02em;
}

.section-desc {
  color: var(--text-secondary);
  font-size: 1.05rem;
}

.section-content {
  max-width: 1200px;
  margin: 0 auto;
}

/* ── Card Grid ── */
.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: 1.5rem;
}

.card {
  background: var(--bg-card);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius);
  padding: 1.75rem;
  transition: var(--transition);
  position: relative;
  overflow: hidden;
}

.card::before {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 2px;
  background: linear-gradient(90deg, transparent, var(--accent), transparent);
  opacity: 0;
  transition: var(--transition);
}

.card:hover {
  background: var(--bg-card-hover);
  border-color: rgba(59, 130, 246, 0.2);
  transform: translateY(-4px);
  box-shadow: var(--shadow-glow);
}

.card:hover::before { opacity: 1; }

.card-tag {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  font-weight: 500;
  color: var(--accent-light);
  padding: 0.25rem 0.6rem;
  background: var(--accent-subtle);
  border-radius: var(--radius-xs);
  margin-bottom: 1rem;
  letter-spacing: 0.05em;
  text-transform: uppercase;
}

.card-title {
  font-family: var(--font-display);
  font-size: 1.25rem;
  font-weight: 600;
  margin-bottom: 0.75rem;
  line-height: 1.3;
}

.card-desc {
  color: var(--text-secondary);
  font-size: 0.9rem;
  line-height: 1.6;
  margin-bottom: 1rem;
}

.card-meta {
  display: flex;
  gap: 1rem;
  font-size: 0.75rem;
  color: var(--text-muted);
}

.card-meta span { display: flex; align-items: center; gap: 4px; }

/* ── Daily Fact Card ── */
.daily-fact-card {
  background: linear-gradient(135deg, var(--accent-subtle), var(--purple-subtle));
  border: 1px solid var(--glass-border);
  border-radius: var(--radius);
  padding: 2.5rem;
  margin-bottom: 3rem;
  position: relative;
  overflow: hidden;
}

.daily-fact-card::before {
  content: '';
  position: absolute;
  top: -50%; right: -50%;
  width: 100%; height: 100%;
  background: radial-gradient(circle, var(--accent-glow) 0%, transparent 70%);
  pointer-events: none;
}

.daily-fact-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 1.5rem;
  position: relative;
}

.daily-fact-badge {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 500;
  color: var(--accent-light);
  letter-spacing: 0.1em;
  text-transform: uppercase;
}

.daily-fact-date {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--text-muted);
}

.daily-fact-title {
  font-family: var(--font-display);
  font-size: 1.75rem;
  font-weight: 700;
  margin-bottom: 1rem;
  position: relative;
}

.daily-fact-body {
  font-size: 1.05rem;
  color: var(--text-secondary);
  line-height: 1.8;
  position: relative;
}

.daily-fact-source {
  margin-top: 1.5rem;
  font-size: 0.8rem;
  color: var(--text-muted);
  font-style: italic;
  position: relative;
}

/* ── Puzzle Card ── */
.puzzle-card {
  background: var(--bg-card);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius);
  padding: 2.5rem;
  text-align: center;
  margin-bottom: 3rem;
  position: relative;
}

.puzzle-badge {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 500;
  color: var(--gold);
  letter-spacing: 0.1em;
  text-transform: uppercase;
  padding: 0.3rem 0.75rem;
  background: var(--gold-subtle);
  border-radius: var(--radius-xs);
  margin-bottom: 1.5rem;
}

.puzzle-question {
  font-family: var(--font-display);
  font-size: 1.5rem;
  font-weight: 600;
  margin-bottom: 1.5rem;
  line-height: 1.5;
}

.puzzle-answer {
  font-size: 1.05rem;
  color: var(--accent-light);
  margin-top: 1.5rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--glass-border);
}

/* ── Timeline ── */
.timeline {
  position: relative;
  max-width: 800px;
  margin: 0 auto;
  padding-left: 3rem;
}

.timeline::before {
  content: '';
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 2px;
  background: linear-gradient(to bottom, var(--accent), var(--purple), transparent);
}

.timeline-item {
  position: relative;
  margin-bottom: 3rem;
  padding-left: 1.5rem;
}

.timeline-item::before {
  content: '';
  position: absolute;
  left: -3.35rem;
  top: 0.5rem;
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--accent);
  box-shadow: 0 0 12px var(--accent-glow);
}

.timeline-year {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  font-weight: 500;
  color: var(--accent-light);
  margin-bottom: 0.5rem;
}

.timeline-title {
  font-family: var(--font-display);
  font-size: 1.25rem;
  font-weight: 600;
  margin-bottom: 0.5rem;
}

.timeline-desc {
  color: var(--text-secondary);
  font-size: 0.9rem;
  line-height: 1.7;
}

/* ── AI Status Card ── */
.ai-status-card {
  background: var(--bg-card);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius);
  overflow: hidden;
  margin-bottom: 2rem;
}

.ai-status-header {
  display: flex;
  align-items: center;
  gap: 1rem;
  padding: 1.5rem 2rem;
  border-bottom: 1px solid var(--glass-border);
}

.ai-avatar svg { width: 48px; height: 48px; }

.ai-status-info { flex: 1; }

.ai-status-name {
  font-family: var(--font-display);
  font-size: 1.1rem;
  font-weight: 600;
  margin-bottom: 0.1rem;
}

.ai-status-desc {
  font-size: 0.8rem;
  color: var(--text-muted);
}

.ai-status-badge {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  padding: 0.25rem 0.6rem;
  border-radius: var(--radius-xs);
  letter-spacing: 0.05em;
}

.ai-status-badge.active {
  color: #22c55e;
  background: rgba(34, 197, 94, 0.1);
}

.ai-status-body {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  padding: 1.5rem 2rem;
  gap: 1rem;
  border-bottom: 1px solid var(--glass-border);
}

.ai-metric { text-align: center; }

.ai-metric-value {
  display: block;
  font-family: var(--font-mono);
  font-size: 1.5rem;
  font-weight: 600;
  color: var(--accent-light);
  margin-bottom: 0.25rem;
}

.ai-metric-label {
  font-size: 0.7rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.ai-log {
  padding: 1.5rem 2rem;
  max-height: 200px;
  overflow-y: auto;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  line-height: 2;
}

.ai-log-entry {
  color: var(--text-muted);
  border-bottom: 1px solid rgba(255,255,255,0.03);
  padding-bottom: 0.25rem;
}

.ai-log-entry:last-child { border-bottom: none; }

.ai-log-entry .log-time { color: var(--text-muted); opacity: 0.6; }
.ai-log-entry .log-ok { color: #22c55e; }
.ai-log-entry .log-info { color: var(--accent-light); }
.ai-log-entry .log-warn { color: var(--gold); }

.ai-actions {
  display: flex;
  gap: 1rem;
  flex-wrap: wrap;
}

/* ── Buttons ── */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.75rem 1.5rem;
  font-family: var(--font-body);
  font-size: 0.9rem;
  font-weight: 500;
  border-radius: var(--radius-sm);
  border: none;
  cursor: pointer;
  text-decoration: none;
  transition: var(--transition);
}

.btn-primary {
  background: var(--accent);
  color: white;
  box-shadow: 0 2px 12px var(--accent-glow);
}

.btn-primary:hover {
  background: var(--accent-light);
  box-shadow: 0 4px 24px var(--accent-glow);
  transform: translateY(-2px);
}

.btn-ghost {
  background: transparent;
  color: var(--text-secondary);
  border: 1px solid var(--glass-border);
}

.btn-ghost:hover {
  color: var(--accent-light);
  border-color: var(--accent);
  background: var(--accent-subtle);
}

.btn-sm { padding: 0.5rem 1rem; font-size: 0.8rem; }

/* ── Footer ── */
.footer {
  position: relative;
  z-index: 1;
  padding: 4rem 2rem 2rem;
  border-top: 1px solid var(--glass-border);
  background: var(--bg-secondary);
}

.footer-inner {
  max-width: 600px;
  margin: 0 auto;
  text-align: center;
}

.footer-logo {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  margin-bottom: 1rem;
  color: var(--text-primary);
  font-family: var(--font-display);
  font-size: 1.1rem;
}

.footer-logo .logo-icon { width: 28px; height: 28px; }

.footer-tagline {
  color: var(--text-muted);
  font-size: 0.85rem;
  margin-bottom: 0.5rem;
}

.footer-copy {
  color: var(--text-muted);
  font-size: 0.75rem;
  opacity: 0.6;
}

/* ── Back to Top ── */
.back-to-top {
  position: fixed;
  bottom: 2rem;
  right: 2rem;
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: var(--accent);
  color: white;
  border: none;
  cursor: pointer;
  font-size: 1.1rem;
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  transform: translateY(20px);
  transition: var(--transition);
  z-index: 50;
  box-shadow: 0 4px 16px var(--accent-glow);
}

.back-to-top.visible {
  opacity: 1;
  transform: translateY(0);
}

.back-to-top:hover {
  background: var(--accent-light);
  transform: translateY(-2px);
}

/* ── 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 fadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}

@keyframes scrollPulse {
  0%, 100% { opacity: 0.4; transform: scaleY(1); }
  50% { opacity: 1; transform: scaleY(1.2); }
}

@keyframes float {
  0%, 100% { transform: translateY(0px) rotate(0deg); }
  33% { transform: translateY(-10px) rotate(1deg); }
  66% { transform: translateY(5px) rotate(-1deg); }
}

/* ── Scroll Reveal ── */
/* ── Scroll Reveal ──
   Content is VISIBLE BY DEFAULT. The hidden state is applied by JavaScript only
   (via .reveal-pending), so if the observer never fires — or JS never runs —
   the failure mode is "no animation", never "invisible content". */
.reveal {
  opacity: 1;
  transform: none;
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.reveal.reveal-pending {
  opacity: 0;
  transform: translateY(30px);
}

/* ── Responsive ── */
@media (max-width: 768px) {
  .nav-links { display: none; }
  .nav-toggle { display: flex; }

  .nav-links.open {
    display: flex;
    flex-direction: column;
    position: absolute;
    top: 72px;
    left: 0; right: 0;
    background: rgba(10, 10, 26, 0.95);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    padding: 1rem;
    border-bottom: 1px solid var(--glass-border);
  }

  .hero { padding: 5rem 1.5rem 3rem; }
  .hero-decoration { display: none; }
  .section { padding: 4rem 1.5rem; }
  .card-grid { grid-template-columns: 1fr; }
  .ai-status-body { grid-template-columns: repeat(2, 1fr); }
  .daily-fact-card { padding: 1.5rem; }
  .daily-fact-title { font-size: 1.3rem; }
}

@media (max-width: 480px) {
  .hero-actions { flex-direction: column; align-items: center; }
  .ai-status-body { grid-template-columns: 1fr 1fr; }
  .ai-actions { flex-direction: column; }
}

/* ── Card Footer (used by illusion cards) ── */
.card-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem;
  padding-top: 1rem;
  border-top: 1px solid rgba(255, 255, 255, 0.04);
}

/* ── Illusion Plans Download Cards ── */
.illusion-card {
  background: var(--bg-card);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius);
  padding: 1.75rem;
  transition: var(--transition);
  position: relative;
  overflow: hidden;
}

.illusion-card::before {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 2px;
  background: linear-gradient(90deg, transparent, var(--accent-light), transparent);
  opacity: 0;
  transition: var(--transition);
}

.illusion-card:hover {
  background: var(--bg-card-hover);
  border-color: rgba(59, 130, 246, 0.2);
  transform: translateY(-4px);
  box-shadow: var(--shadow-glow);
}

.illusion-card:hover::before { opacity: 1; }

.illusion-card .card-tag {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  font-weight: 500;
  color: var(--accent-light);
  padding: 0.25rem 0.6rem;
  background: var(--accent-subtle);
  border-radius: var(--radius-xs);
  margin-bottom: 0.75rem;
  letter-spacing: 0.05em;
  text-transform: uppercase;
}

.illusion-card .card-title {
  font-family: var(--font-display);
  font-size: 1.15rem;
  font-weight: 600;
  margin-bottom: 0.5rem;
  line-height: 1.3;
  color: var(--text-primary);
}

.illusion-card .card-desc {
  color: var(--text-secondary);
  font-size: 0.85rem;
  line-height: 1.6;
  margin-bottom: 1rem;
}

.illusion-card .card-author {
  font-size: 0.8rem;
  color: var(--text-muted);
  font-style: italic;
  margin-bottom: 1rem;
}

.illusion-card .file-size {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  color: var(--text-muted);
  letter-spacing: 0.03em;
}

.illusion-card .download-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.55rem 1.2rem;
  font-family: var(--font-body);
  font-size: 0.85rem;
  font-weight: 600;
  color: white;
  background: var(--accent);
  border: 1px solid var(--accent);
  border-radius: var(--radius-xs);
  text-decoration: none;
  transition: var(--transition);
  cursor: pointer;
  box-shadow: 0 2px 8px var(--accent-glow);
}

.illusion-card .download-btn:hover {
  background: var(--accent-light);
  color: white;
  border-color: var(--accent-light);
  box-shadow: 0 4px 20px var(--accent-glow);
  transform: translateY(-1px);
}

/* ── Illusion filter bar ── */
.illusion-filter-bar {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  justify-content: center;
  margin-bottom: 2rem;
}

.illusion-filter-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  padding: 0.4rem 0.9rem;
  font-family: var(--font-body);
  font-size: 0.8rem;
  font-weight: 500;
  color: var(--text-secondary);
  background: var(--bg-card);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-xs);
  cursor: pointer;
  transition: var(--transition);
}

.illusion-filter-btn:hover {
  color: var(--accent-light);
  border-color: var(--accent);
  background: var(--accent-subtle);
}

.illusion-filter-btn.active {
  color: var(--accent-light);
  background: var(--accent-subtle);
  border-color: var(--accent);
}

/* ── Illusion search bar ── */
.illusion-search-bar {
  display: flex;
  justify-content: center;
  margin-bottom: 1.5rem;
}

.illusion-search-input {
  width: 100%;
  max-width: 400px;
  padding: 0.6rem 1rem;
  font-family: var(--font-body);
  font-size: 0.9rem;
  color: var(--text-primary);
  background: var(--bg-card);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-sm);
  outline: none;
  transition: var(--transition);
}

.illusion-search-input::placeholder {
  color: var(--text-muted);
}

.illusion-search-input:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 2px var(--accent-glow);
}

/* ── Download progress toast ── */
.download-toast {
  position: fixed;
  bottom: 2rem;
  left: 50%;
  transform: translateX(-50%) translateY(100px);
  padding: 0.75rem 1.5rem;
  background: var(--accent);
  color: white;
  border-radius: var(--radius-sm);
  font-size: 0.85rem;
  font-weight: 500;
  box-shadow: 0 4px 24px var(--accent-glow);
  z-index: 200;
  transition: transform 0.3s ease;
  pointer-events: none;
}

.download-toast.show {
  transform: translateX(-50%) translateY(0);
}

/* ── Splat Gallery (gaussian splat viewer) ── */
.splat-picker {
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem;
  justify-content: center;
  margin-bottom: 1.25rem;
}

.splat-pick-btn {
  appearance: none;
  -webkit-appearance: none;
  background: var(--bg-card);
  border: 1px solid var(--glass-border);
  color: var(--text-secondary);
  font-family: var(--font-body);
  font-size: 0.9rem;
  font-weight: 500;
  padding: 0.6rem 1.2rem;
  border-radius: 999px;
  cursor: pointer;
  transition: var(--transition);
}

.splat-pick-btn:hover {
  background: var(--bg-card-hover);
  color: var(--text-primary);
  transform: translateY(-1px);
}

.splat-pick-btn.active {
  background: var(--accent-subtle);
  border-color: var(--accent);
  color: var(--accent-light);
  box-shadow: 0 0 16px var(--accent-glow);
}

.splat-stage {
  position: relative;
  width: 100%;
  max-width: 960px;
  margin: 0 auto;
  aspect-ratio: 16 / 9;
  min-height: 420px;
  border-radius: var(--radius);
  overflow: hidden;
  background: #000;
  border: 1px solid var(--glass-border);
  box-shadow: var(--shadow);
}

.splat-stage iframe {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  border: none;
  display: block;
}

.splat-placeholder {
  position: absolute;
  inset: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 0.75rem;
  padding: 2rem;
  text-align: center;
  background:
    radial-gradient(ellipse at 50% 40%, var(--accent-subtle), transparent 65%),
    linear-gradient(180deg, rgba(15, 15, 42, 0.9), rgba(10, 10, 26, 0.95));
}

.splat-icon {
  width: 72px;
  height: 72px;
  margin-bottom: 0.5rem;
}

.splat-title {
  font-family: var(--font-display);
  font-size: 1.6rem;
  color: var(--text-primary);
}

.splat-desc {
  max-width: 42ch;
  color: var(--text-secondary);
  font-size: 0.95rem;
}

.splat-actions {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  margin-top: 0.75rem;
  flex-wrap: wrap;
  justify-content: center;
}

@media (max-width: 640px) {
  .splat-stage { aspect-ratio: auto; min-height: 320px; }
}

/* ── Section Full Pages & Previews ── */
/* Slim hero strip on full pages — only the "Back to Home" link lives here;
   chapter tag / title / description are shown once in the section header below. */
.section-hero {
  position: relative;
  z-index: 1;
  padding: 6.75rem 2rem 0;
  text-align: center;
  overflow: hidden;
}

.section-hero::before {
  content: '';
  position: absolute;
  top: -40%;
  left: 50%;
  transform: translateX(-50%);
  width: 80%;
  height: 120%;
  background: radial-gradient(ellipse, var(--accent-subtle) 0%, transparent 70%);
  pointer-events: none;
}

.section-hero-inner { position: relative; max-width: 760px; margin: 0 auto; }

.back-link {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--text-muted);
  text-decoration: none;
  letter-spacing: 0.05em;
  margin-bottom: 1.75rem;
  transition: var(--transition);
}

.back-link:hover { color: var(--accent-light); }

/* "View all" button in index.html section headers */
.view-all-btn { display: inline-block; margin-top: 1.25rem; }

@media (max-width: 768px) {
  .section-hero { padding: 6.25rem 1.5rem 0; }
}

/* ── Reduced Motion ── */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
  html { scroll-behavior: auto; }
  .reveal { opacity: 1; transform: none; }
}