:root {
  --bg-dark: #1a1a1e;
  --bg-light: #f0eeeb;
  --panel-dark: #242428;
  --panel-light: #ffffff;
  --text-primary: #e8e6e3;
  --text-secondary: #a09d98;
  --text-dark: #2a2a2a;
  --accent: #c4956a;
  --accent-hover: #d4a57a;
  --accent-muted: #8a7055;
  --accent-glow: rgba(196,149,106,0.15);
  --border: rgba(255,255,255,0.08);
  --border-light: rgba(0,0,0,0.08);
  --radius: 8px;
  --shadow: 0 4px 24px rgba(0,0,0,0.4);
}

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

html, body {
  height: 100%;
  font-family: 'Segoe UI', system-ui, -apple-system, sans-serif;
  overflow: hidden;
}

body {
  display: flex;
  background: var(--bg-dark);
  color: var(--text-primary);
}

/* ── Mobile Notice ── */
.mobile-notice {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 200;
  background: #2a2520;
  border-bottom: 1px solid var(--accent-muted);
  padding: 10px 16px;
  transition: transform 0.3s ease;
}
.mobile-notice.hidden { transform: translateY(-100%); }
.notice-content {
  display: flex;
  align-items: center;
  gap: 12px;
  font-size: 0.78rem;
  color: var(--text-secondary);
}
.notice-content strong { color: var(--accent); }
.notice-close {
  margin-left: auto;
  padding: 4px 10px;
  border: 1px solid var(--border);
  background: var(--bg-dark);
  color: var(--text-secondary);
  border-radius: var(--radius);
  font-size: 0.7rem;
  cursor: pointer;
}

/* ── Version Nav ── */
.version-nav {
  display: flex;
  gap: 6px;
  flex-wrap: wrap;
  padding: 4px 0 8px;
  border-bottom: 1px solid var(--border);
  font-size: 0.62rem;
}
.version-nav a,
.version-nav span {
  padding: 3px 8px;
  border-radius: 4px;
  text-decoration: none;
  color: var(--text-secondary);
  transition: all 0.15s;
}
.version-nav a:hover {
  background: var(--accent-glow);
  color: var(--accent);
}
.version-nav .current {
  background: var(--accent);
  color: var(--bg-dark);
  font-weight: 600;
}

/* ── UI Panel ── */
#ui {
  width: 340px;
  min-width: 340px;
  height: 100vh;
  display: flex;
  flex-direction: column;
  background: var(--panel-dark);
  border-right: 1px solid var(--border);
  padding: 14px;
  gap: 10px;
  overflow-y: auto;
  z-index: 10;
}

header { position: relative; }

header h1 {
  font-size: 1.05rem;
  font-weight: 600;
  letter-spacing: 0.02em;
  color: var(--text-primary);
  margin-bottom: 2px;
}

.demo-badge {
  display: inline-block;
  font-size: 0.6rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  background: var(--accent);
  color: var(--bg-dark);
  padding: 3px 10px;
  border-radius: 4px;
  margin-bottom: 6px;
}

.subtitle {
  font-size: 0.72rem;
  color: var(--accent);
  font-weight: 500;
  margin-bottom: 3px;
}

.tagline {
  font-size: 0.68rem;
  color: var(--text-secondary);
  font-style: italic;
  margin-bottom: 4px;
}

.hint {
  font-size: 0.65rem;
  color: var(--text-secondary);
  font-style: italic;
  line-height: 1.4;
}

/* ── Demo Guide ── */
.demo-guide {
  padding: 10px;
  background: var(--accent-glow);
  border: 1px solid rgba(196,149,106,0.2);
  border-radius: var(--radius);
}
.guide-steps {
  padding-left: 18px;
  font-size: 0.72rem;
  color: var(--text-secondary);
  line-height: 1.6;
}
.guide-steps strong { color: var(--accent); }
.guide-hint {
  font-size: 0.65rem;
  color: var(--accent-muted);
  margin-top: 6px;
  font-style: italic;
}

/* ── Presets ── */
.presets-section {
  padding-top: 4px;
}
.preset-buttons {
  display: flex;
  flex-direction: column;
  gap: 5px;
}
.preset-btn {
  padding: 7px 10px;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  background: var(--bg-dark);
  color: var(--text-secondary);
  font-size: 0.72rem;
  cursor: pointer;
  transition: all 0.15s ease;
  text-align: left;
}
.preset-btn:hover {
  border-color: var(--accent-muted);
  color: var(--text-primary);
}
.preset-btn.primary {
  background: var(--accent);
  color: var(--bg-dark);
  border-color: var(--accent);
  font-weight: 600;
}
.preset-btn.primary:hover {
  background: var(--accent-hover);
}

/* ── Section ── */
.section {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.section h2 {
  font-size: 0.68rem;
  font-weight: 600;
  color: var(--text-secondary);
  text-transform: uppercase;
  letter-spacing: 0.08em;
}

/* ── Diagnostics ── */
.diagnostics-panel {
  border-top: 1px solid var(--border);
  padding-top: 6px;
}
.diagnostics-header {
  margin: 0;
}
.diag-toggle {
  width: 100%;
  text-align: left;
  padding: 4px 0;
  background: none;
  border: none;
  color: var(--text-secondary);
  font-size: 0.68rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  cursor: pointer;
  font-family: inherit;
}
.diag-toggle:hover { color: var(--accent); }
.diagnostics-content {
  display: flex;
  flex-direction: column;
  gap: 3px;
  overflow: hidden;
  transition: max-height 0.3s ease;
  max-height: 300px;
}
.diagnostics-content.collapsed {
  max-height: 0;
}
#diag-error { color: #c45c4a; }

/* ── State Badge ── */
.state-section {
  padding: 10px;
  background: var(--accent-glow);
  border: 1px solid rgba(196,149,106,0.2);
  border-radius: var(--radius);
}

.state-badge {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--accent);
  text-align: center;
  padding: 6px;
  border-radius: var(--radius);
  background: rgba(196,149,106,0.1);
  border: 1px solid rgba(196,149,106,0.3);
  letter-spacing: 0.05em;
  transition: all 0.4s ease;
}

.state-badge.state-idle { color: #6a6864; border-color: rgba(106,104,100,0.4); background: rgba(106,104,100,0.08); }
.state-badge.state-reading { color: #c4956a; border-color: rgba(196,149,106,0.5); background: rgba(196,149,106,0.12); }
.state-badge.state-sleeping { color: #4a6a8a; border-color: rgba(74,106,138,0.4); background: rgba(74,106,138,0.08); }
.state-badge.state-observer { color: #8a7055; border-color: rgba(138,112,85,0.4); background: rgba(138,112,85,0.08); }
.state-badge.state-awake { color: #d4a57a; border-color: rgba(212,165,122,0.4); background: rgba(212,165,122,0.08); }

/* ── Narrative ── */
.narrative-section {
  padding: 8px;
  border-left: 2px solid var(--accent-muted);
}

.narrative-text {
  font-size: 0.75rem;
  line-height: 1.5;
  color: var(--text-primary);
  font-style: italic;
  min-height: 2.5em;
}

.state-duration {
  font-size: 0.62rem;
  color: var(--text-secondary);
  margin-top: 4px;
}

/* ── Mode Buttons ── */
.mode-buttons, .angle-buttons {
  display: flex;
  gap: 5px;
  flex-wrap: wrap;
}

.mode-btn, .angle-btn {
  flex: 1;
  min-width: 50px;
  padding: 5px 8px;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  background: var(--bg-dark);
  color: var(--text-secondary);
  font-size: 0.68rem;
  cursor: pointer;
  transition: all 0.15s ease;
}

.mode-btn:hover, .angle-btn:hover {
  border-color: var(--accent-muted);
  color: var(--text-primary);
}

.mode-btn.active, .angle-btn.active {
  background: var(--accent);
  color: var(--bg-dark);
  border-color: var(--accent);
  font-weight: 600;
}

/* ── Cycle Button ── */
.cycle-btn {
  flex: 1;
  padding: 6px;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  background: var(--bg-dark);
  color: var(--text-secondary);
  font-size: 0.72rem;
  cursor: pointer;
  transition: all 0.2s ease;
}

.cycle-btn.active {
  background: #3a5a3a;
  color: #8ada8a;
  border-color: #5a8a5a;
}

/* ── Motion Controls ── */
.motion-controls {
  padding: 8px;
  background: var(--accent-glow);
  border: 1px solid rgba(196,149,106,0.2);
  border-radius: var(--radius);
}

.motion-row {
  display: flex;
  gap: 8px;
}

.play-btn, .step-btn {
  flex: 1;
  padding: 8px;
  border-radius: var(--radius);
  border: 1px solid var(--accent);
  background: var(--accent);
  color: var(--bg-dark);
  font-size: 0.78rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.15s ease;
}

.play-btn:hover, .step-btn:hover {
  background: var(--accent-hover);
}

.play-btn.paused {
  background: var(--bg-dark);
  color: var(--accent);
  border-color: var(--accent);
}

.slider-wrap {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 2px 0;
}

.slider-wrap label {
  font-size: 0.7rem;
  color: var(--text-secondary);
  min-width: 60px;
  flex-shrink: 0;
}

.slider-wrap input[type="range"] {
  flex: 1;
  accent-color: var(--accent);
  height: 4px;
}

.slider-wrap span {
  font-size: 0.7rem;
  color: var(--accent);
  min-width: 48px;
  text-align: right;
  font-variant-numeric: tabular-nums;
}

/* ── Parts List ── */
.parts-list {
  display: flex;
  flex-direction: column;
  gap: 3px;
  max-height: 180px;
  overflow-y: auto;
  padding-right: 4px;
}

.parts-list::-webkit-scrollbar { width: 4px; }
.parts-list::-webkit-scrollbar-thumb {
  background: var(--border);
  border-radius: 2px;
}

.part-item {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 4px 6px;
  border-radius: 5px;
  cursor: pointer;
  transition: background 0.1s;
  font-size: 0.74rem;
}

.part-item:hover { background: rgba(255,255,255,0.04); }
.part-item.selected {
  background: rgba(196,149,106,0.12);
  border-left: 2px solid var(--accent);
}

.part-item input[type="checkbox"] {
  accent-color: var(--accent);
  width: 13px;
  height: 13px;
  flex-shrink: 0;
}

.part-item .part-color {
  width: 9px;
  height: 9px;
  border-radius: 50%;
  flex-shrink: 0;
  border: 1px solid rgba(255,255,255,0.2);
}

.part-item .part-name { flex: 1; color: var(--text-primary); }
.part-item .part-cat {
  font-size: 0.58rem;
  color: var(--text-secondary);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

/* ── Toggles ── */
.toggles {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  padding-top: 4px;
  border-top: 1px solid var(--border);
}

.toggles.compact {
  border-top: none;
  padding-top: 0;
}

.toggle {
  display: flex;
  align-items: center;
  gap: 5px;
  font-size: 0.7rem;
  color: var(--text-secondary);
  cursor: pointer;
  user-select: none;
}

.toggle input {
  accent-color: var(--accent);
  width: 13px;
  height: 13px;
}

/* ── Info Panels ── */
.info-panel {
  flex: 1;
  min-height: 80px;
  padding-top: 6px;
  border-top: 1px solid var(--border);
}

#info-content, #state-info-content {
  font-size: 0.73rem;
  line-height: 1.5;
  color: var(--text-secondary);
}

.info-placeholder {
  font-style: italic;
  opacity: 0.6;
}

.info-row {
  display: flex;
  gap: 6px;
  margin-bottom: 5px;
}

.info-row .label {
  display: block;
  font-size: 0.6rem;
  color: var(--accent-muted);
  text-transform: uppercase;
  letter-spacing: 0.06em;
  min-width: 70px;
  flex-shrink: 0;
}

.info-row .value {
  color: var(--text-primary);
}

/* ── Actions ── */
.actions {
  display: flex;
  gap: 6px;
  padding-top: 2px;
}

.actions button {
  flex: 1;
  padding: 5px 10px;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  background: var(--bg-dark);
  color: var(--text-primary);
  font-size: 0.7rem;
  cursor: pointer;
  transition: all 0.15s ease;
}

.actions button:hover {
  background: var(--accent);
  color: var(--bg-dark);
  border-color: var(--accent);
}

/* ── Footer ── */
footer {
  padding-top: 4px;
  border-top: 1px solid var(--border);
  font-size: 0.62rem;
  color: var(--text-secondary);
  line-height: 1.5;
}

footer code {
  background: var(--bg-dark);
  padding: 1px 3px;
  border-radius: 3px;
  font-family: 'SF Mono', monospace;
  font-size: 0.58rem;
}

.version-footer {
  margin-top: 4px;
  font-size: 0.6rem;
  color: var(--accent-muted);
}
.version-footer a { color: var(--accent-muted); }

/* ── Canvas ── */
#canvas-container {
  flex: 1;
  position: relative;
  height: 100vh;
}

#canvas-container canvas {
  display: block;
  width: 100%;
  height: 100%;
}

/* ── Labels in 3D ── */
.label-tag {
  position: absolute;
  pointer-events: none;
  background: rgba(26,26,30,0.85);
  border: 1px solid var(--accent-muted);
  border-radius: 4px;
  padding: 2px 7px;
  font-size: 0.68rem;
  color: var(--accent);
  white-space: nowrap;
  transform: translate(-50%, -120%);
  opacity: 0;
  transition: opacity 0.2s;
  z-index: 5;
}

.label-tag.visible { opacity: 1; }

body.light-mode .label-tag {
  background: rgba(240,238,235,0.9);
  border-color: var(--accent);
  color: var(--text-dark);
}

/* ── Motion Path Line ── */
.motion-path-line {
  position: absolute;
  pointer-events: none;
  width: 2px;
  background: rgba(196,149,106,0.4);
  transform-origin: top;
  opacity: 0;
  transition: opacity 0.3s;
  z-index: 3;
}

.motion-path-line.visible { opacity: 1; }

/* ── Loading Overlay ── */
#loading-overlay {
  position: fixed;
  top: 0; left: 0; right: 0; bottom: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--bg-dark);
  color: var(--text-secondary);
  font-size: 0.9rem;
  z-index: 100;
  transition: opacity 0.3s ease;
}

#loading-overlay.hidden {
  opacity: 0;
  pointer-events: none;
}

.loading-content {
  text-align: center;
  max-width: 420px;
  padding: 32px;
}

.loading-title {
  font-size: 1.1rem;
  font-weight: 500;
  color: var(--text-primary);
  margin-bottom: 8px;
}

.loading-status {
  font-size: 0.82rem;
  color: var(--text-secondary);
  margin-bottom: 12px;
  min-height: 1.4em;
}

.loading-resources {
  font-size: 0.72rem;
  color: var(--accent-muted);
  margin-bottom: 20px;
  line-height: 1.6;
}

.loading-spinner {
  width: 32px;
  height: 32px;
  border: 3px solid var(--border);
  border-top-color: var(--accent);
  border-radius: 50%;
  margin: 0 auto 20px;
  animation: spin 1s linear infinite;
}

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

.loading-error {
  text-align: left;
  background: rgba(196,90,74,0.08);
  border: 1px solid rgba(196,90,74,0.3);
  border-radius: var(--radius);
  padding: 16px;
}

.loading-error.hidden { display: none; }

.error-title {
  font-size: 0.85rem;
  font-weight: 600;
  color: #c45c4a;
  margin-bottom: 10px;
}

.error-suggestions {
  font-size: 0.75rem;
  color: var(--text-secondary);
  padding-left: 18px;
  line-height: 1.7;
  margin-bottom: 12px;
}

.reload-btn {
  display: block;
  width: 100%;
  padding: 8px;
  border-radius: var(--radius);
  border: 1px solid #c45c4a;
  background: transparent;
  color: #c45c4a;
  font-size: 0.78rem;
  cursor: pointer;
  transition: all 0.15s;
}
.reload-btn:hover {
  background: rgba(196,90,74,0.1);
}

/* ── Disabled sections ── */
.disabled {
  opacity: 0.35;
  pointer-events: none;
}

/* ── Light mode overrides ── */
body.light-mode {
  background: var(--bg-light);
  color: var(--text-dark);
}

body.light-mode #ui {
  background: var(--panel-light);
  border-right-color: var(--border-light);
}

body.light-mode header h1 { color: var(--text-dark); }
body.light-mode .subtitle { color: #8b6914; }
body.light-mode .tagline,
body.light-mode .hint,
body.light-mode .section h2,
body.light-mode .toggle,
body.light-mode footer,
body.light-mode .part-item .part-cat,
body.light-mode .info-row .label,
body.light-mode .slider-wrap label { color: #6a6864; }

body.light-mode .part-item .part-name,
body.light-mode .info-row .value { color: var(--text-dark); }

body.light-mode .mode-btn,
body.light-mode .angle-btn,
body.light-mode .actions button,
body.light-mode .preset-btn {
  background: var(--bg-light);
  color: var(--text-dark);
  border-color: var(--border-light);
}

body.light-mode .mode-btn.active,
body.light-mode .angle-btn.active,
body.light-mode .actions button:hover {
  background: var(--accent);
  color: #fff;
}

body.light-mode .preset-btn:hover {
  border-color: var(--accent-muted);
}
body.light-mode .preset-btn.primary {
  background: var(--accent);
  color: #fff;
}

body.light-mode .play-btn.paused {
  background: var(--bg-light);
  color: var(--accent);
}

body.light-mode .cycle-btn.active {
  background: #d0e8d0;
  color: #2a5a2a;
}

body.light-mode #loading-overlay {
  background: var(--bg-light);
  color: var(--text-dark);
}

body.light-mode .mobile-notice {
  background: #f5f0eb;
}

body.light-mode .version-nav a:hover {
  background: var(--accent-glow);
}

/* ── Responsive ── */
@media (max-width: 768px) {
  #ui {
    width: 280px;
    min-width: 280px;
    padding: 10px;
  }
  .version-nav {
    font-size: 0.58rem;
  }
  .preset-buttons {
    flex-direction: row;
    flex-wrap: wrap;
  }
  .preset-btn {
    flex: 1;
    min-width: 80px;
  }
}