:root {
  --bg: #0d1117;
  --panel: rgba(18, 24, 38, 0.85);
  --panel-border: rgba(255, 255, 255, 0.12);
  --panel-glow: rgba(79, 172, 254, 0.15);
  --text-main: #f0f6fc;
  --text-muted: #8b949e;
  --accent-cyan: #00f2fe;
  --accent-blue: #4facfe;
  --accent-purple: #9b51e0;
  --accent-gold: #ffd166;
  --accent-green: #06d6a0;
  --accent-red: #ef476f;
  --font-family: 'Outfit', 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
  -webkit-tap-highlight-color: transparent;
}

html, body {
  width: 100%;
  height: 100%;
  overflow: hidden;
  background-color: var(--bg);
  font-family: var(--font-family);
  color: var(--text-main);
  user-select: none;
  -webkit-user-select: none;
}

#app {
  position: fixed;
  inset: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  background: radial-gradient(circle at 50% 30%, #172133 0%, #0a0d14 100%);
}

#canvas-container {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
}

canvas {
  display: block;
  width: 100%;
  height: 100%;
  outline: none;
}

/* Glassmorphic Top HUD */
#hud-top {
  position: absolute;
  top: 18px;
  left: 20px;
  right: 20px;
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  pointer-events: none;
  z-index: 10;
}

.hud-glass-card {
  background: var(--panel);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border: 1px solid var(--panel-border);
  box-shadow: 0 8px 32px 0 rgba(0, 0, 0, 0.4), inset 0 0 0 1px rgba(255, 255, 255, 0.05);
  border-radius: 16px;
  padding: 12px 20px;
  pointer-events: auto;
}

.score-container {
  display: flex;
  flex-direction: column;
}

.score-label {
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 1.5px;
  text-transform: uppercase;
  color: var(--accent-cyan);
  display: flex;
  align-items: center;
  gap: 6px;
}

.score-value {
  font-size: 38px;
  font-weight: 900;
  line-height: 1.1;
  background: linear-gradient(135deg, #ffffff 30%, var(--accent-cyan) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  text-shadow: 0 0 20px rgba(0, 242, 254, 0.3);
}

.high-score {
  font-size: 12px;
  color: var(--text-muted);
  font-weight: 600;
  margin-top: 2px;
}

.stats-container {
  display: flex;
  gap: 16px;
  align-items: center;
}

.stat-item {
  display: flex;
  flex-direction: column;
  align-items: flex-end;
}

.stat-title {
  font-size: 10px;
  font-weight: 700;
  color: var(--text-muted);
  letter-spacing: 1px;
  text-transform: uppercase;
}

.stat-val {
  font-size: 20px;
  font-weight: 800;
  color: var(--accent-gold);
}

/* Audio & Settings Buttons */
.icon-btn {
  background: var(--panel);
  border: 1px solid var(--panel-border);
  color: var(--text-main);
  border-radius: 12px;
  width: 44px;
  height: 44px;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  pointer-events: auto;
  transition: all 0.2s cubic-bezier(0.16, 1, 0.3, 1);
  box-shadow: 0 4px 14px rgba(0, 0, 0, 0.25);
}

.icon-btn:hover {
  background: rgba(255, 255, 255, 0.15);
  transform: translateY(-2px);
  border-color: var(--accent-cyan);
}

.icon-btn.active {
  border-color: var(--accent-green);
  color: var(--accent-green);
}

/* Stunt Banner Notification */
#stunt-banner {
  position: absolute;
  top: 96px;
  left: 50%;
  transform: translateX(-50%) scale(0.9);
  opacity: 0;
  transition: all 0.3s cubic-bezier(0.175, 0.885, 0.32, 1.275);
  pointer-events: none;
  z-index: 20;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 6px;
}

#stunt-banner.show {
  opacity: 1;
  transform: translateX(-50%) scale(1.08);
}

.stunt-badge {
  background: linear-gradient(135deg, rgba(255, 95, 210, 0.95), rgba(67, 217, 255, 0.95));
  padding: 8px 24px;
  border-radius: 30px;
  font-size: 18px;
  font-weight: 900;
  letter-spacing: 2px;
  text-transform: uppercase;
  color: #fff;
  box-shadow: 0 0 35px rgba(255, 95, 210, 0.7), inset 0 1px 0 rgba(255, 255, 255, 0.6);
  text-shadow: 0 2px 4px rgba(0, 0, 0, 0.4);
}

.ai-judge-title {
  font-size: 11px;
  font-weight: 800;
  color: var(--accent-cyan);
  background: rgba(13, 17, 23, 0.85);
  padding: 4px 14px;
  border-radius: 12px;
  border: 1px solid rgba(0, 242, 254, 0.4);
  letter-spacing: 1px;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.3);
}

/* Drift Combo Multiplier (Floating Center-Left) */
#drift-combo-hud {
  position: absolute;
  top: 110px;
  left: 20px;
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  pointer-events: none;
  z-index: 15;
  opacity: 0;
  transform: translateX(-20px);
  transition: all 0.25s cubic-bezier(0.16, 1, 0.3, 1);
}

#drift-combo-hud.active {
  opacity: 1;
  transform: translateX(0);
}

.combo-badge {
  background: linear-gradient(135deg, #ff5fd2, #ffd166);
  padding: 6px 16px;
  border-radius: 20px;
  font-size: 14px;
  font-weight: 900;
  letter-spacing: 1px;
  color: #0d1117;
  box-shadow: 0 0 20px rgba(255, 95, 210, 0.6);
  display: flex;
  align-items: center;
  gap: 6px;
  animation: pulseCombo 0.8s infinite alternate ease-in-out;
}

@keyframes pulseCombo {
  from { transform: scale(1); filter: brightness(1); }
  to { transform: scale(1.05); filter: brightness(1.2); }
}

.combo-bar-wrap {
  width: 130px;
  height: 6px;
  background: rgba(255, 255, 255, 0.12);
  border-radius: 3px;
  margin-top: 6px;
  overflow: hidden;
}

.combo-bar-fill {
  width: 0%;
  height: 100%;
  background: linear-gradient(90deg, var(--accent-cyan), #ff5fd2);
  border-radius: 3px;
  transition: width 0.1s linear;
}

/* Railway Block Signal (Semáforo de Bloco) */
.rail-signal-box {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 6px 12px;
  background: rgba(10, 15, 24, 0.6);
  border: 1px solid rgba(255, 255, 255, 0.12);
  border-radius: 12px;
  box-shadow: inset 0 1px 3px rgba(0, 0, 0, 0.4);
}

.signal-lamp {
  width: 13px;
  height: 13px;
  border-radius: 50%;
  border: 1px solid rgba(255, 255, 255, 0.3);
  transition: all 0.25s ease;
}

.signal-lamp.green {
  background: #10b981;
  box-shadow: 0 0 12px #10b981, inset 0 0 4px #a7f3d0;
}

.signal-lamp.amber {
  background: #f59e0b;
  box-shadow: 0 0 14px #f59e0b, inset 0 0 4px #fde68a;
  animation: pulse-amber 1s infinite alternate;
}

@keyframes pulse-amber {
  0% { transform: scale(0.95); opacity: 0.85; }
  100% { transform: scale(1.1); opacity: 1; }
}

.signal-info {
  display: flex;
  flex-direction: column;
}

.signal-title {
  font-size: 8px;
  font-weight: 800;
  color: var(--text-muted);
  letter-spacing: 0.8px;
}

.signal-status {
  font-size: 11px;
  font-weight: 800;
  color: #fff;
  letter-spacing: 0.5px;
}

/* Train Skin Badge & Quick Switch */
.skin-selector-card {
  display: flex;
  align-items: center;
  gap: 10px;
  cursor: pointer;
  pointer-events: auto;
  transition: transform 0.2s ease;
}

.skin-selector-card:hover {
  transform: translateY(-2px);
  border-color: var(--accent-cyan);
}

.skin-swatch {
  width: 14px;
  height: 14px;
  border-radius: 50%;
  box-shadow: 0 0 8px currentColor;
}

/* Locomotive Driver Cab Console HUD (Bottom Center) */
#keyboard-hud.cab-console-panel {
  position: absolute;
  bottom: 20px;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  background: linear-gradient(180deg, rgba(22, 28, 40, 0.94) 0%, rgba(12, 16, 24, 0.98) 100%);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border: 1px solid rgba(255, 255, 255, 0.16);
  border-top: 2px solid var(--accent-cyan);
  padding: 8px 24px 12px;
  border-radius: 18px;
  box-shadow: 0 14px 44px rgba(0, 0, 0, 0.65), inset 0 1px 0 rgba(255, 255, 255, 0.15);
  z-index: 10;
  pointer-events: none;
}

.cab-console-badge {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 10px;
  font-weight: 800;
  letter-spacing: 1.5px;
  color: var(--accent-gold);
  text-transform: uppercase;
  opacity: 0.9;
  margin-bottom: 2px;
}

.cab-badge-rivet {
  width: 5px;
  height: 5px;
  border-radius: 50%;
  background: #64748b;
  box-shadow: inset 0 1px 1px #fff, 0 1px 2px #000;
}

.cab-console-content {
  display: flex;
  gap: 22px;
  align-items: center;
}

.bogie-control-group {
  display: flex;
  align-items: center;
  gap: 12px;
}

.bogie-title {
  display: flex;
  flex-direction: column;
}

.bogie-name {
  font-size: 13px;
  font-weight: 800;
  letter-spacing: 1px;
  text-transform: uppercase;
  color: var(--accent-cyan);
}

.bogie-track-indicator {
  font-size: 10px;
  font-weight: 700;
  color: var(--text-muted);
}

.key-cluster {
  display: flex;
  gap: 8px;
}

.key-cap {
  width: 42px;
  height: 42px;
  background: #1c2436;
  border: 1px solid rgba(255, 255, 255, 0.15);
  border-bottom: 3px solid rgba(255, 255, 255, 0.25);
  border-radius: 10px;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  font-size: 15px;
  font-weight: 800;
  color: #fff;
  transition: all 0.08s ease;
  box-shadow: 0 4px 10px rgba(0, 0, 0, 0.3);
}

.key-cap small {
  font-size: 8px;
  color: var(--text-muted);
  font-weight: 600;
  margin-top: -2px;
}

.key-cap.active {
  background: linear-gradient(135deg, var(--accent-blue), var(--accent-cyan));
  color: #0d1117;
  border-color: #fff;
  border-bottom-width: 1px;
  transform: translateY(2px);
  box-shadow: 0 0 16px rgba(0, 242, 254, 0.7);
}

.key-cap.active small {
  color: #0d1117;
}

.controls-divider {
  width: 1px;
  height: 38px;
  background: rgba(255, 255, 255, 0.1);
}

/* Modals & Overlays (Tutorial, Game Over) */
.overlay-modal {
  position: absolute;
  inset: 0;
  background: rgba(8, 11, 18, 0.85);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 100;
  transition: opacity 0.3s ease;
}

.overlay-modal[hidden] {
  display: none;
}

.modal-card {
  background: var(--panel);
  border: 1px solid rgba(255, 255, 255, 0.18);
  border-radius: 24px;
  padding: 32px 36px;
  max-width: 440px;
  width: 90%;
  text-align: center;
  box-shadow: 0 24px 60px rgba(0, 0, 0, 0.7), 0 0 40px rgba(0, 242, 254, 0.15);
  animation: modalEnter 0.35s cubic-bezier(0.16, 1, 0.3, 1);
}

@keyframes modalEnter {
  from { transform: scale(0.92) translateY(20px); opacity: 0; }
  to { transform: scale(1) translateY(0); opacity: 1; }
}

.modal-title {
  font-size: 26px;
  font-weight: 900;
  letter-spacing: -0.5px;
  margin-bottom: 8px;
}

.modal-subtitle {
  font-size: 14px;
  color: var(--text-muted);
  margin-bottom: 24px;
  line-height: 1.5;
}

.tutorial-keys-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
  margin-bottom: 28px;
  text-align: left;
}

.tut-key-box {
  background: rgba(255, 255, 255, 0.04);
  border: 1px solid rgba(255, 255, 255, 0.08);
  border-radius: 14px;
  padding: 14px;
}

.tut-key-header {
  font-size: 12px;
  font-weight: 800;
  color: var(--accent-cyan);
  text-transform: uppercase;
  margin-bottom: 8px;
}

.tut-key-desc {
  font-size: 11px;
  color: var(--text-muted);
  line-height: 1.4;
}

.action-btn {
  display: block;
  width: 100%;
  padding: 15px 0;
  border-radius: 14px;
  border: none;
  font-family: inherit;
  font-size: 16px;
  font-weight: 800;
  letter-spacing: 0.5px;
  cursor: pointer;
  transition: all 0.2s cubic-bezier(0.16, 1, 0.3, 1);
}

.btn-primary {
  background: linear-gradient(135deg, var(--accent-blue), var(--accent-cyan));
  color: #0a101d;
  box-shadow: 0 8px 24px rgba(0, 242, 254, 0.35);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 12px 30px rgba(0, 242, 254, 0.5);
}

.btn-primary:active {
  transform: translateY(1px);
}

.btn-secondary {
  background: rgba(255, 255, 255, 0.08);
  color: var(--text-main);
  margin-top: 12px;
  border: 1px solid rgba(255, 255, 255, 0.1);
}

.btn-secondary:hover {
  background: rgba(255, 255, 255, 0.14);
}

/* Crash / Game Over specific elements */
.gameover-score-wrap {
  margin: 20px 0;
}

.gameover-score {
  font-size: 54px;
  font-weight: 900;
  color: var(--accent-cyan);
  line-height: 1;
}

.gameover-best {
  font-size: 14px;
  color: var(--text-muted);
  font-weight: 600;
  margin-top: 6px;
}

/* Desktop Cab Console: make keycaps interactive by mouse */
#keyboard-hud .key-cap {
  pointer-events: auto;
  cursor: pointer;
  transition: transform 0.08s ease, background 0.12s ease, box-shadow 0.12s ease;
}
#keyboard-hud .key-cap:active,
#keyboard-hud .key-cap.active {
  transform: translateY(2px) scale(0.96);
  background: var(--accent-cyan);
  color: #0b111a;
  box-shadow: 0 0 16px rgba(0, 242, 254, 0.6);
}

/* ==========================================================================
   MOBILE ON-SCREEN TOUCH CONTROLS (2 Left Buttons + 2 Right Buttons)
   ========================================================================== */
#mobile-touch-hud.mobile-touch-container {
  position: absolute;
  bottom: calc(16px + env(safe-area-inset-bottom, 0px));
  left: 0;
  right: 0;
  width: 100%;
  padding: 0 calc(12px + env(safe-area-inset-right, 0px)) 0 calc(12px + env(safe-area-inset-left, 0px));
  display: flex;
  justify-content: space-between;
  align-items: flex-end;
  pointer-events: none;
  z-index: 60;
  box-sizing: border-box;
}

.touch-side {
  display: flex;
  flex-direction: column;
  gap: 10px;
  pointer-events: auto;
}

.touch-center {
  position: absolute;
  left: 50%;
  transform: translateX(-50%);
  bottom: 0;
  pointer-events: auto;
}

.touch-action-btn {
  display: flex;
  align-items: center;
  gap: 8px;
  min-width: 124px;
  height: 52px;
  padding: 6px 14px;
  border-radius: 14px;
  background: rgba(14, 20, 32, 0.88);
  backdrop-filter: blur(18px);
  -webkit-backdrop-filter: blur(18px);
  border: 1.5px solid rgba(255, 255, 255, 0.14);
  color: #fff;
  cursor: pointer;
  touch-action: none;
  user-select: none;
  -webkit-user-select: none;
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.55), inset 0 1px 0 rgba(255, 255, 255, 0.12);
  transition: transform 0.08s ease, filter 0.12s ease, background 0.12s ease, box-shadow 0.12s ease;
  will-change: transform;
}

/* Front Bogie Styling (Cyan Accent) */
.touch-action-btn.btn-front {
  border-left: 3.5px solid var(--accent-cyan);
}
.touch-right .touch-action-btn.btn-front {
  border-left: 1.5px solid rgba(255, 255, 255, 0.14);
  border-right: 3.5px solid var(--accent-cyan);
}
.touch-action-btn.btn-front .touch-label {
  color: var(--accent-cyan);
}
.touch-action-btn.btn-front .touch-icon-box {
  color: var(--accent-cyan);
}

/* Rear Bogie Styling (Blue/Violet Accent) */
.touch-action-btn.btn-rear {
  border-left: 3.5px solid var(--accent-blue);
}
.touch-right .touch-action-btn.btn-rear {
  border-left: 1.5px solid rgba(255, 255, 255, 0.14);
  border-right: 3.5px solid var(--accent-blue);
}
.touch-action-btn.btn-rear .touch-label {
  color: var(--accent-blue);
}
.touch-action-btn.btn-rear .touch-icon-box {
  color: var(--accent-blue);
}

.touch-icon-box {
  font-size: 15px;
  font-weight: 900;
  display: flex;
  align-items: center;
  justify-content: center;
  width: 28px;
  height: 28px;
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.07);
  box-shadow: inset 0 1px 2px rgba(0, 0, 0, 0.4);
}

.touch-info {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  line-height: 1.15;
}
.touch-info.text-right {
  align-items: flex-end;
}

.touch-label {
  font-size: 11px;
  font-weight: 900;
  letter-spacing: 0.8px;
}

.touch-sub {
  font-size: 9px;
  font-weight: 700;
  color: var(--text-muted);
  letter-spacing: 0.5px;
}

/* Center Straighten / Align Button */
.touch-center-btn {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 3px;
  min-width: 66px;
  height: 52px;
  padding: 4px 8px;
  border-radius: 14px;
  background: rgba(20, 26, 38, 0.88);
  backdrop-filter: blur(18px);
  -webkit-backdrop-filter: blur(18px);
  border: 1.5px solid rgba(255, 209, 102, 0.4);
  color: var(--accent-gold);
  cursor: pointer;
  touch-action: none;
  user-select: none;
  -webkit-user-select: none;
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.55);
  font-size: 9px;
  font-weight: 800;
  letter-spacing: 0.5px;
  transition: transform 0.08s ease, filter 0.12s ease;
  will-change: transform;
}

/* Active Pressed Feedback */
.touch-action-btn:active,
.touch-action-btn.active {
  transform: scale(0.92);
  background: rgba(28, 38, 56, 0.98);
  box-shadow: 0 0 20px rgba(0, 242, 254, 0.5);
  filter: brightness(1.25);
}
.touch-action-btn.btn-rear:active,
.touch-action-btn.btn-rear.active {
  box-shadow: 0 0 20px rgba(79, 172, 254, 0.5);
}

.touch-center-btn:active,
.touch-center-btn.active {
  transform: scale(0.92);
  filter: brightness(1.35);
  box-shadow: 0 0 18px rgba(255, 209, 102, 0.6);
}

/* Desktop vs Mobile Media Queries */
@media (min-width: 901px) and (pointer: fine) {
  #mobile-touch-hud {
    display: none !important;
  }
  #keyboard-hud {
    display: flex;
  }
}

@media (max-width: 900px), (pointer: coarse) {
  #keyboard-hud {
    display: none !important;
  }
  #mobile-touch-hud {
    display: flex;
  }
}

/* Small Screens / Portrait Phones Adjustments */
@media (max-width: 520px) {
  #mobile-touch-hud.mobile-touch-container {
    bottom: calc(10px + env(safe-area-inset-bottom, 0px));
    left: calc(8px + env(safe-area-inset-left, 0px));
    right: calc(8px + env(safe-area-inset-right, 0px));
    gap: 6px;
  }
  .touch-side {
    gap: 8px;
  }
  .touch-action-btn {
    min-width: 102px;
    height: 48px;
    padding: 4px 8px;
    gap: 6px;
  }
  .touch-icon-box {
    width: 24px;
    height: 24px;
    font-size: 13px;
  }
  .touch-label {
    font-size: 10px;
  }
  .touch-sub {
    font-size: 8px;
  }
  .touch-center-btn {
    min-width: 58px;
    height: 48px;
    font-size: 8px;
  }
}

@media (max-width: 380px) {
  .touch-action-btn {
    min-width: 92px;
    padding: 3px 6px;
  }
  .touch-sub {
    display: none;
  }
}

/* Responsive adjustments for Top HUD on mobile to prevent overflow and maintain perfect centering */
@media (max-width: 768px) {
  #hud-top {
    top: calc(8px + env(safe-area-inset-top, 0px));
    left: calc(8px + env(safe-area-inset-left, 0px));
    right: calc(8px + env(safe-area-inset-right, 0px));
    gap: 6px;
    align-items: center;
  }
  .hud-glass-card {
    padding: 6px 10px;
    border-radius: 12px;
  }
  .score-value {
    font-size: 22px;
  }
  .high-score {
    font-size: 9px;
  }
  .stats-container {
    gap: 6px;
  }
  .skin-selector-card .stat-title,
  .skin-selector-card .stat-val {
    display: none;
  }
  .skin-selector-card {
    padding: 6px;
    min-width: unset;
  }
  .rail-signal-box .signal-info {
    display: none;
  }
  .rail-signal-box {
    padding: 6px;
    min-width: unset;
  }
  .icon-btn {
    width: 34px;
    height: 34px;
    border-radius: 8px;
  }
  .stat-val {
    font-size: 15px;
  }
  .stat-title {
    font-size: 8px;
  }
  #drift-combo-hud {
    top: 74px;
    left: calc(10px + env(safe-area-inset-left, 0px));
  }
  #stunt-banner {
    top: 74px;
  }
}