/* ------------------------------------------------------------------
   Tokens
------------------------------------------------------------------ */
:root {
  --bg-canvas: #05070b;
  --bg-app: #0a0d13;
  --bg-surface: #12151d;
  --bg-surface-2: #171b25;
  --bg-elevated: #1c212c;

  --border: #23272f;
  --border-strong: #2e333e;

  --text-primary: #edf0f5;
  --text-secondary: #a7adba;
  --text-muted: #6d7481;
  --text-faint: #4a5060;

  --accent: #6b7cff;
  --accent-hover: #7d8dff;
  --accent-glow: rgba(107, 124, 255, 0.35);
  --accent-soft: rgba(107, 124, 255, 0.12);

  --success: #2fd48a;
  --success-glow: rgba(47, 212, 138, 0.35);
  --warning: #f5b544;
  --danger: #f26565;

  --radius-sm: 6px;
  --radius: 10px;
  --radius-lg: 14px;

  --shadow-1: 0 1px 2px rgba(0,0,0,0.4);
  --shadow-2: 0 8px 24px rgba(0,0,0,0.4);
  --shadow-3: 0 24px 60px rgba(0,0,0,0.55);

  --font-sans: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --font-mono: ui-monospace, "SF Mono", "JetBrains Mono", Consolas, "Liberation Mono", monospace;

  --dur: 180ms;
  --ease: cubic-bezier(0.4, 0.0, 0.2, 1);
}

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

html, body {
  width: 100%;
  height: 100%;
  overflow: hidden;
  background: var(--bg-canvas);
  color: var(--text-primary);
  font-family: var(--font-sans);
  font-size: 14px;
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
}

button, input {
  font-family: inherit;
  font-size: inherit;
  color: inherit;
}

kbd {
  display: inline-block;
  padding: 1px 6px;
  font-family: var(--font-mono);
  font-size: 11px;
  background: var(--bg-elevated);
  border: 1px solid var(--border-strong);
  border-bottom-width: 2px;
  border-radius: 4px;
  color: var(--text-secondary);
  vertical-align: 1px;
}

code {
  font-family: var(--font-mono);
  font-size: 0.9em;
  padding: 1px 5px;
  background: var(--bg-elevated);
  border-radius: 4px;
  color: var(--text-secondary);
}

.hidden { display: none !important; }

/* ------------------------------------------------------------------
   Canvas
------------------------------------------------------------------ */
#scene {
  display: block;
  width: 100vw;
  height: 100vh;
  touch-action: none;
}

/* Hidden tracker video; preview is rendered separately */
#cam {
  position: fixed;
  bottom: 20px;
  right: 20px;
  width: 220px;
  height: 165px;
  object-fit: cover;
  transform: scaleX(-1);
  border-radius: var(--radius);
  background: #000;
  z-index: 5;
  border: 1px solid var(--border);
  box-shadow: var(--shadow-2);
  transition: opacity var(--dur) var(--ease), transform var(--dur) var(--ease);
}
#cam.hidden-preview {
  opacity: 0;
  transform: scaleX(-1) translateY(10px);
  pointer-events: none;
}

/* ------------------------------------------------------------------
   Overlays (welcome / error)
------------------------------------------------------------------ */
.overlay {
  position: fixed;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 24px;
  z-index: 100;
  background:
    radial-gradient(1200px 800px at 50% 40%, rgba(107,124,255,0.08) 0%, transparent 60%),
    radial-gradient(1000px 700px at 80% 90%, rgba(163,92,255,0.06) 0%, transparent 70%),
    var(--bg-app);
  animation: fadeIn 300ms var(--ease);
}
.overlay::before {
  /* subtle grid pattern */
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(255,255,255,0.02) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255,255,255,0.02) 1px, transparent 1px);
  background-size: 40px 40px;
  mask-image: radial-gradient(circle at center, black 20%, transparent 75%);
  pointer-events: none;
}

.welcome {
  position: relative;
  max-width: 520px;
  width: 100%;
  padding: 40px 40px 32px;
  background: linear-gradient(180deg, var(--bg-surface) 0%, var(--bg-surface-2) 100%);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-3);
  animation: rise 320ms var(--ease);
}

.brand {
  display: flex;
  align-items: center;
  gap: 14px;
  margin-bottom: 22px;
}
.brand-mark {
  width: 40px;
  height: 40px;
  flex-shrink: 0;
  filter: drop-shadow(0 0 12px var(--accent-glow));
}
.brand-text h1 {
  font-size: 20px;
  font-weight: 600;
  letter-spacing: -0.3px;
  line-height: 1.2;
}
.brand-text .tag {
  font-size: 12px;
  color: var(--text-muted);
  margin-top: 2px;
  letter-spacing: 0.1px;
}

.lede {
  font-size: 15px;
  color: var(--text-secondary);
  line-height: 1.6;
  margin-bottom: 24px;
}

.features {
  list-style: none;
  margin: 0 0 28px;
  padding: 16px 16px;
  background: rgba(255,255,255,0.02);
  border: 1px solid var(--border);
  border-radius: var(--radius);
}
.features li {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 6px 0;
  font-size: 13px;
  color: var(--text-secondary);
}
.features .fi {
  width: 18px;
  height: 18px;
  flex-shrink: 0;
  color: var(--accent);
}

.fineprint {
  margin-top: 18px;
  font-size: 12px;
  color: var(--text-muted);
  text-align: center;
}

/* Error card */
.error-card { text-align: center; }
.err-icon {
  width: 44px;
  height: 44px;
  margin: 0 auto 14px;
  color: var(--danger);
}
.err-icon svg { width: 100%; height: 100%; }
.error-card h2 {
  font-size: 20px;
  font-weight: 600;
  margin-bottom: 10px;
  letter-spacing: -0.2px;
}
.err-actions {
  display: flex;
  justify-content: center;
  margin-top: 20px;
}
.err-help {
  margin-top: 24px;
  padding-top: 20px;
  border-top: 1px solid var(--border);
  text-align: left;
}
.err-help summary {
  cursor: pointer;
  font-size: 13px;
  color: var(--text-secondary);
  user-select: none;
  padding: 4px 0;
}
.err-help summary:hover { color: var(--text-primary); }
.err-help ul {
  list-style: none;
  margin-top: 12px;
}
.err-help li {
  font-size: 13px;
  color: var(--text-muted);
  padding: 5px 0 5px 16px;
  position: relative;
  line-height: 1.55;
}
.err-help li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 12px;
  width: 4px;
  height: 4px;
  border-radius: 50%;
  background: var(--text-faint);
}

/* ------------------------------------------------------------------
   Buttons
------------------------------------------------------------------ */
.btn {
  position: relative;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 10px 18px;
  font-weight: 500;
  font-size: 14px;
  border: 1px solid transparent;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: background var(--dur) var(--ease), border-color var(--dur) var(--ease), transform var(--dur) var(--ease), box-shadow var(--dur) var(--ease);
  white-space: nowrap;
  user-select: none;
}
.btn:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}
.btn:disabled { cursor: default; opacity: 0.7; }

.btn-primary {
  background: var(--accent);
  color: white;
  box-shadow: 0 1px 0 rgba(255,255,255,0.15) inset, 0 8px 20px -8px var(--accent-glow);
}
.btn-primary:hover:not(:disabled) {
  background: var(--accent-hover);
  transform: translateY(-1px);
  box-shadow: 0 1px 0 rgba(255,255,255,0.2) inset, 0 12px 24px -8px var(--accent-glow);
}
.btn-primary:active:not(:disabled) {
  transform: translateY(0);
}

.btn-secondary {
  background: var(--bg-elevated);
  color: var(--text-primary);
  border-color: var(--border-strong);
}
.btn-secondary:hover:not(:disabled) {
  background: #232935;
  border-color: #3a4051;
}

.btn-large {
  width: 100%;
  padding: 13px 20px;
  font-size: 15px;
  border-radius: var(--radius);
}
.btn-small { padding: 7px 12px; font-size: 12px; }

.btn-content, .btn-loader {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  transition: opacity var(--dur) var(--ease);
}
.btn-loader {
  position: absolute;
  inset: 0;
  justify-content: center;
  opacity: 0;
  pointer-events: none;
}
.btn.is-loading .btn-content { opacity: 0; }
.btn.is-loading .btn-loader { opacity: 1; }
.btn.is-loading { pointer-events: none; }

.btn-arrow {
  width: 16px;
  height: 16px;
  transition: transform var(--dur) var(--ease);
}
.btn:hover .btn-arrow { transform: translateX(2px); }

.spinner {
  width: 14px;
  height: 14px;
  border: 2px solid rgba(255,255,255,0.3);
  border-top-color: white;
  border-radius: 50%;
  animation: spin 640ms linear infinite;
}

.icon-btn {
  width: 36px;
  height: 36px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  background: rgba(18, 21, 29, 0.85);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  color: var(--text-secondary);
  cursor: pointer;
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  transition: background var(--dur) var(--ease), color var(--dur) var(--ease), border-color var(--dur) var(--ease);
}
.icon-btn:hover {
  background: rgba(28, 33, 44, 0.9);
  color: var(--text-primary);
  border-color: var(--border-strong);
}
.icon-btn:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }
.icon-btn svg { width: 18px; height: 18px; }
.icon-btn.small { width: 28px; height: 28px; }
.icon-btn.small svg { width: 14px; height: 14px; }

/* ------------------------------------------------------------------
   Runtime HUD
------------------------------------------------------------------ */
#hud {
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 10;
  animation: fadeIn 400ms var(--ease);
}
#hud > * { pointer-events: auto; }

.hud-top {
  position: absolute;
  top: 20px;
  right: 20px;
  display: flex;
  align-items: center;
  gap: 10px;
}

/* Tracking pill */
.track-pill {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 8px 14px;
  background: rgba(18, 21, 29, 0.85);
  border: 1px solid var(--border);
  border-radius: 999px;
  font-size: 12px;
  color: var(--text-secondary);
  font-weight: 500;
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease);
}
.track-pill .dot {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--text-muted);
  box-shadow: 0 0 0 0 transparent;
  transition: background var(--dur) var(--ease), box-shadow var(--dur) var(--ease);
}
.track-pill[data-state="tracking"] {
  color: var(--text-primary);
}
.track-pill[data-state="tracking"] .dot {
  background: var(--success);
  box-shadow: 0 0 0 4px rgba(47, 212, 138, 0.15);
  animation: pulse 2s var(--ease) infinite;
}
.track-pill[data-state="lost"] { color: var(--warning); border-color: rgba(245, 181, 68, 0.25); }
.track-pill[data-state="lost"] .dot { background: var(--warning); }
.track-pill[data-state="waiting"] .dot { background: var(--text-muted); }

.hud-buttons {
  display: flex;
  gap: 8px;
}

/* ------------------------------------------------------------------
   Settings drawer
------------------------------------------------------------------ */
#panel {
  position: absolute;
  top: 68px;
  right: 20px;
  width: 340px;
  max-height: calc(100vh - 88px);
  overflow-y: auto;
  background: rgba(15, 18, 25, 0.94);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-3);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  animation: slideIn 220ms var(--ease);
}
#panel::-webkit-scrollbar { width: 6px; }
#panel::-webkit-scrollbar-track { background: transparent; }
#panel::-webkit-scrollbar-thumb { background: var(--border-strong); border-radius: 3px; }

.panel-header {
  position: sticky;
  top: 0;
  z-index: 1;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 16px 18px;
  background: rgba(15, 18, 25, 0.94);
  border-bottom: 1px solid var(--border);
  backdrop-filter: blur(20px);
}
.panel-header h2 {
  font-size: 14px;
  font-weight: 600;
  letter-spacing: -0.1px;
}

.group {
  padding: 18px 18px;
  border-bottom: 1px solid var(--border);
}
.group:last-of-type { border-bottom: none; }
.group h3 {
  font-size: 10px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 1.2px;
  color: var(--text-muted);
  margin-bottom: 14px;
}

/* Slider control */
.control {
  margin-bottom: 14px;
}
.control:last-child { margin-bottom: 0; }
.control-row {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  margin-bottom: 8px;
}
.control label {
  font-size: 13px;
  color: var(--text-secondary);
  font-weight: 400;
}
.control .value {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--text-primary);
  font-weight: 500;
  font-variant-numeric: tabular-nums;
}
.control .unit {
  color: var(--text-muted);
  margin-left: 3px;
  font-weight: 400;
}

/* Standalone label (used above dropdown) */
.control-label {
  display: block;
  font-size: 13px;
  color: var(--text-secondary);
  margin-bottom: 8px;
}

/* Select / dropdown */
.select {
  width: 100%;
  padding: 9px 34px 9px 12px;
  font-size: 13px;
  color: var(--text-primary);
  background-color: var(--bg-elevated);
  border: 1px solid var(--border-strong);
  border-radius: var(--radius-sm);
  cursor: pointer;
  appearance: none;
  -webkit-appearance: none;
  background-image: url("data:image/svg+xml;utf8,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 24 24' fill='none' stroke='%23a7adba' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpath d='M6 9 L12 15 L18 9'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 12px center;
  transition: border-color var(--dur) var(--ease), background-color var(--dur) var(--ease);
}
.select:hover { border-color: #3a4051; background-color: #232935; }
.select:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }
.select option { background: var(--bg-elevated); color: var(--text-primary); }

/* Range input styling */
input[type="range"] {
  -webkit-appearance: none;
  appearance: none;
  width: 100%;
  height: 20px;
  background: transparent;
  cursor: pointer;
}
input[type="range"]::-webkit-slider-runnable-track {
  height: 4px;
  background: var(--bg-elevated);
  border-radius: 2px;
}
input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 16px;
  height: 16px;
  margin-top: -6px;
  background: var(--text-primary);
  border: 2px solid var(--accent);
  border-radius: 50%;
  box-shadow: 0 0 0 0 var(--accent-glow);
  transition: box-shadow var(--dur) var(--ease), transform var(--dur) var(--ease);
}
input[type="range"]:hover::-webkit-slider-thumb {
  box-shadow: 0 0 0 4px var(--accent-soft);
}
input[type="range"]:active::-webkit-slider-thumb {
  transform: scale(1.1);
  box-shadow: 0 0 0 6px var(--accent-soft);
}
input[type="range"]::-moz-range-track {
  height: 4px;
  background: var(--bg-elevated);
  border-radius: 2px;
}
input[type="range"]::-moz-range-thumb {
  width: 14px;
  height: 14px;
  background: var(--text-primary);
  border: 2px solid var(--accent);
  border-radius: 50%;
  cursor: pointer;
}
input[type="range"]:focus-visible::-webkit-slider-thumb {
  box-shadow: 0 0 0 4px var(--accent-glow);
}

/* Switch (checkbox) */
.switch {
  display: flex;
  align-items: center;
  gap: 12px;
  cursor: pointer;
  padding: 8px 0;
  user-select: none;
}
.switch input {
  position: absolute;
  opacity: 0;
  pointer-events: none;
}
.switch-track {
  position: relative;
  width: 34px;
  height: 20px;
  background: var(--bg-elevated);
  border: 1px solid var(--border-strong);
  border-radius: 999px;
  transition: background var(--dur) var(--ease), border-color var(--dur) var(--ease);
  flex-shrink: 0;
}
.switch-thumb {
  position: absolute;
  top: 2px;
  left: 2px;
  width: 14px;
  height: 14px;
  background: var(--text-secondary);
  border-radius: 50%;
  transition: transform var(--dur) var(--ease), background var(--dur) var(--ease);
}
.switch input:checked ~ .switch-track {
  background: var(--accent);
  border-color: var(--accent);
}
.switch input:checked ~ .switch-track .switch-thumb {
  transform: translateX(14px);
  background: white;
}
.switch input:focus-visible ~ .switch-track {
  box-shadow: 0 0 0 3px var(--accent-glow);
}
.switch-label {
  font-size: 13px;
  color: var(--text-secondary);
  line-height: 1.4;
}
.switch-hint {
  display: block;
  font-size: 11px;
  color: var(--text-muted);
  margin-top: 1px;
}

/* Panel footer */
.panel-footer {
  padding: 14px 18px;
  border-top: 1px solid var(--border);
}
.panel-footer .btn { width: 100%; }
.panel-footer-row {
  display: flex;
  gap: 8px;
}
.panel-footer-row .btn { flex: 1; }

/* Stats */
.stats {
  padding: 14px 18px 16px;
  border-top: 1px solid var(--border);
  background: rgba(0,0,0,0.15);
}
.stat {
  display: flex;
  justify-content: space-between;
  padding: 2px 0;
  font-family: var(--font-mono);
  font-size: 11px;
  font-variant-numeric: tabular-nums;
}
.stat-k { color: var(--text-muted); text-transform: uppercase; letter-spacing: 0.5px; }
.stat-v { color: var(--text-secondary); }

/* ------------------------------------------------------------------
   Animations
------------------------------------------------------------------ */
@keyframes fadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}
@keyframes rise {
  from { opacity: 0; transform: translateY(12px); }
  to { opacity: 1; transform: translateY(0); }
}
@keyframes slideIn {
  from { opacity: 0; transform: translateY(-4px) scale(0.98); }
  to { opacity: 1; transform: translateY(0) scale(1); }
}
@keyframes pulse {
  0%, 100% { box-shadow: 0 0 0 4px rgba(47, 212, 138, 0.15); }
  50% { box-shadow: 0 0 0 7px rgba(47, 212, 138, 0.08); }
}
@keyframes spin {
  to { transform: rotate(360deg); }
}
@keyframes flashPulse {
  0%   { box-shadow: 0 0 0 0 var(--accent-glow); }
  60%  { box-shadow: 0 0 0 10px transparent; }
  100% { box-shadow: 0 0 0 0 transparent; }
}
.icon-btn.flash, .btn.flash {
  animation: flashPulse 320ms var(--ease);
}
@media (prefers-reduced-motion: reduce) {
  * { animation-duration: 0.01ms !important; transition-duration: 0.01ms !important; }
}

/* ------------------------------------------------------------------
   Small screens
------------------------------------------------------------------ */
@media (max-width: 620px) {
  .welcome { padding: 28px 22px; }
  #panel {
    top: auto;
    right: 12px;
    left: 12px;
    width: auto;
    max-height: 70vh;
    bottom: 12px;
  }
  #cam { width: 140px; height: 105px; bottom: 12px; right: 12px; }
  .hud-top { top: 12px; right: 12px; }
}