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

body {
  font-family: 'Arial Rounded MT Bold', Arial, sans-serif;
  background: linear-gradient(180deg, #87CEEB 0%, #98FB98 60%, #90EE90 100%);
  min-height: 100vh;
  overflow: hidden;
  user-select: none;
}

#app { display: flex; flex-direction: column; height: 100vh; }

/* ── LEVEL SELECT ─────────────────────────────────────────────────────────── */
#level-select {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: flex-start;
  min-height: 100vh;
  padding: 16px 16px 24px;
  background: linear-gradient(180deg, #1565C0 0%, #1976D2 40%, #0D47A1 100%);
  overflow-y: auto;
  gap: 12px;
}

#ls-thomas {
  animation: bob 2s ease-in-out infinite;
  margin-top: 4px;
}

#ls-title {
  color: #FFD700;
  font-size: 1.8rem;
  text-shadow: 2px 2px 6px rgba(0,0,0,0.6);
  text-align: center;
}

#ls-score-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
  max-width: 600px;
  background: rgba(255,255,255,0.15);
  border-radius: 16px;
  padding: 10px 18px;
  box-shadow: 0 2px 8px rgba(0,0,0,0.2);
}

#ls-score {
  color: #FFD700;
  font-size: 1.15rem;
  font-weight: bold;
  text-shadow: 1px 1px 3px rgba(0,0,0,0.5);
  letter-spacing: 0.5px;
}

.ls-reset-btn {
  background: rgba(183,28,28,0.85);
  color: white;
  border: 2px solid rgba(255,255,255,0.4);
  border-radius: 12px;
  padding: 8px 16px;
  font-size: 0.9rem;
  font-weight: bold;
  cursor: pointer;
  transition: all 0.15s;
  font-family: inherit;
}
.ls-reset-btn:hover {
  background: rgba(198,40,40,1);
  transform: scale(1.05);
  box-shadow: 0 3px 8px rgba(0,0,0,0.3);
}

#ls-groups {
  display: flex;
  flex-direction: column;
  gap: 12px;
  width: 100%;
  max-width: 600px;
}

.ls-group {
  border-radius: 18px;
  padding: 14px 16px;
  box-shadow: 0 4px 12px rgba(0,0,0,0.3);
}

.ls-group[data-group="1"] { background: linear-gradient(135deg, #2E7D32, #43A047); }
.ls-group[data-group="2"] { background: linear-gradient(135deg, #E65100, #F57C00); }
.ls-group[data-group="3"] { background: linear-gradient(135deg, #B71C1C, #E53935); }
.ls-group[data-group="4"] { background: linear-gradient(135deg, #4A148C, #7B1FA2); }
.ls-group[data-group="5"] { background: linear-gradient(135deg, #004D40, #00796B); }

.ls-group-label {
  color: white;
  font-size: 1rem;
  font-weight: bold;
  margin-bottom: 10px;
  text-shadow: 1px 1px 3px rgba(0,0,0,0.4);
}

.ls-levels {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  justify-content: flex-start;
}

.ls-level-btn {
  width: 72px;
  height: 72px;
  border-radius: 50%;
  border: 3px solid rgba(255,255,255,0.6);
  background: white;
  font-size: 1.3rem;
  font-weight: bold;
  color: #333;
  cursor: pointer;
  position: relative;
  box-shadow: 0 4px 8px rgba(0,0,0,0.3);
  transition: all 0.15s;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-direction: column;
}

.ls-level-btn:hover:not(.locked) {
  transform: scale(1.12);
  box-shadow: 0 6px 14px rgba(0,0,0,0.4);
}

.ls-level-btn.unlocked.completed {
  background: linear-gradient(135deg, #FFF9C4, #FFD700);
  border-color: #F9A825;
}

.ls-level-btn.unlocked.completed::after {
  content: '★';
  position: absolute;
  top: -8px;
  right: -4px;
  font-size: 0.85rem;
  color: #F9A825;
  text-shadow: 0 1px 3px rgba(0,0,0,0.4);
}

.ls-level-btn.locked {
  background: #9E9E9E;
  border-color: #757575;
  color: #555;
  cursor: not-allowed;
  opacity: 0.6;
}

.ls-level-btn.locked::before {
  content: '🔒';
  font-size: 0.7rem;
  position: absolute;
  bottom: 6px;
}

#btn-free-mode {
  margin-top: 4px;
  padding: 12px 32px;
  font-size: 1.1rem;
}

/* ── GAME SCREEN ──────────────────────────────────────────────────────────── */
#game-screen {
  display: flex;
  flex-direction: column;
  height: 100vh;
}

/* Header */
#header {
  display: flex; align-items: center; gap: 12px;
  background: linear-gradient(90deg, #1565C0, #1976D2, #1565C0);
  padding: 8px 16px;
  box-shadow: 0 3px 8px rgba(0,0,0,0.4);
  flex-shrink: 0;
}

#btn-back {
  background: rgba(255,255,255,0.2);
  border: 2px solid rgba(255,255,255,0.5);
  font-size: 0.9rem;
  padding: 8px 14px;
  white-space: nowrap;
}
#btn-back:hover { background: rgba(255,255,255,0.35); }

#level-info {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 4px;
}

#level-title-display {
  color: #FFD700;
  font-size: 1.2rem;
  font-weight: bold;
  text-shadow: 1px 1px 4px rgba(0,0,0,0.5);
}

#gaps-counter {
  display: inline-block;
  background: #FF8F00;
  color: white;
  font-size: 0.85rem;
  font-weight: bold;
  padding: 3px 12px;
  border-radius: 20px;
  box-shadow: 0 2px 6px rgba(0,0,0,0.3);
}

#gaps-counter:empty { display: none; }

/* Free mode header title */
#header h1 {
  color: #FFD700; font-size: 1.4rem;
  text-shadow: 2px 2px 4px rgba(0,0,0,0.5);
  flex: 1; text-align: center;
}

#thomas-logo { animation: bob 2s ease-in-out infinite; }

@keyframes bob {
  0%,100% { transform: translateY(0); }
  50% { transform: translateY(-4px); }
}

/* Toolbar */
#toolbar {
  background: linear-gradient(90deg, #FF8F00, #FFA000);
  padding: 8px 12px;
  display: flex; align-items: center; gap: 8px;
  flex-wrap: wrap;
  box-shadow: 0 2px 6px rgba(0,0,0,0.3);
  flex-shrink: 0;
}
#tools-label {
  color: white; font-size: 1rem; font-weight: bold;
  white-space: nowrap;
}
#track-tools {
  display: flex; gap: 6px; flex-wrap: wrap;
}
.tool-btn {
  display: flex; flex-direction: column; align-items: center;
  background: white; border: 3px solid #e0e0e0;
  border-radius: 12px; padding: 6px 8px;
  cursor: pointer; transition: all 0.15s;
  font-size: 0.8rem; font-weight: bold; color: #555;
  min-width: 70px;
}
.tool-btn svg { width: 54px; height: 54px; }
.tool-btn:hover { border-color: #1976D2; transform: scale(1.08); box-shadow: 0 3px 8px rgba(0,0,0,0.2); }
.tool-btn.active { border-color: #1565C0; background: #E3F2FD; box-shadow: 0 0 0 3px #90CAF9; }
.tool-btn.special { border-color: #7B1FA2; }
.tool-btn.special.active { border-color: #7B1FA2; background: #F3E5F5; box-shadow: 0 0 0 3px #CE93D8; }
.tool-btn.eraser { border-color: #c62828; }
.tool-btn.eraser.active { border-color: #c62828; background: #FFEBEE; box-shadow: 0 0 0 3px #EF9A9A; }
.tool-btn span { margin-top: 3px; }

#action-btns { display: flex; gap: 8px; margin-left: auto; }
.action-btn {
  border: none; border-radius: 16px; padding: 10px 18px;
  font-size: 1rem; font-weight: bold; cursor: pointer;
  transition: all 0.15s; box-shadow: 0 4px 0 rgba(0,0,0,0.3);
  color: white;
}
.action-btn:hover { transform: translateY(-2px); box-shadow: 0 6px 0 rgba(0,0,0,0.3); }
.action-btn:active { transform: translateY(2px); box-shadow: 0 2px 0 rgba(0,0,0,0.3); }
.action-btn.green { background: #2E7D32; }
.action-btn.red { background: #C62828; }
.action-btn.orange { background: #E65100; }

/* Main canvas area */
#main-area {
  flex: 1; position: relative; overflow: hidden;
  cursor: crosshair;
}
#grid-canvas, #train-canvas {
  position: absolute; top: 0; left: 0;
  width: 100%; height: 100%;
}
#train-canvas { pointer-events: none; }

/* Gap overlay */
#gap-overlay {
  position: absolute; top: 0; left: 0;
  width: 100%; height: 100%;
  pointer-events: none;
  z-index: 5;
}

.gap-indicator {
  position: absolute;
  border: 3px dashed #FFD700;
  border-radius: 6px;
  background: rgba(255, 215, 0, 0.15);
  pointer-events: none;
  animation: gapPulse 1.2s ease-in-out infinite;
  box-sizing: border-box;
}

.gap-indicator.filled {
  display: none;
}

@keyframes gapPulse {
  0%, 100% { border-color: #FFD700; background: rgba(255,215,0,0.15); }
  50%       { border-color: #FF8F00; background: rgba(255,143,0,0.25); }
}

/* Message overlay */
#message-overlay {
  position: fixed; inset: 0;
  background: rgba(0,0,0,0.5);
  display: flex; align-items: center; justify-content: center;
  z-index: 100;
}
#message-box {
  background: white; border-radius: 24px;
  padding: 32px 40px; text-align: center;
  box-shadow: 0 8px 32px rgba(0,0,0,0.4);
  border: 4px solid #FFD700;
  max-width: 360px;
  animation: popIn 0.3s cubic-bezier(0.34,1.56,0.64,1);
}
@keyframes popIn {
  from { transform: scale(0.5); opacity: 0; }
  to { transform: scale(1); opacity: 1; }
}
#message-icon { font-size: 3.5rem; margin-bottom: 12px; }
#message-text { font-size: 1.2rem; font-weight: bold; color: #333; margin-bottom: 20px; line-height: 1.5; white-space: pre-line; }
#message-actions { display: flex; gap: 12px; justify-content: center; }
#message-close {
  background: #1976D2; color: white; border: none;
  border-radius: 20px; padding: 12px 28px;
  font-size: 1.1rem; font-weight: bold; cursor: pointer;
  box-shadow: 0 4px 0 #0D47A1; transition: all 0.15s;
}
#message-close:hover { background: #1565C0; transform: translateY(-2px); }
#message-close:active { transform: translateY(2px); box-shadow: 0 2px 0 #0D47A1; }
#message-next {
  background: #2E7D32; color: white; border: none;
  border-radius: 20px; padding: 12px 28px;
  font-size: 1.1rem; font-weight: bold; cursor: pointer;
  box-shadow: 0 4px 0 #1B5E20; transition: all 0.15s;
}
#message-next:hover { background: #388E3C; transform: translateY(-2px); }
#message-next:active { transform: translateY(2px); box-shadow: 0 2px 0 #1B5E20; }

/* Puff cloud animation */
@keyframes puff {
  0% { transform: scale(1) translateY(0); opacity: 0.9; }
  100% { transform: scale(2.5) translateY(-30px); opacity: 0; }
}
.puff {
  position: absolute; border-radius: 50%;
  background: white; pointer-events: none;
  animation: puff 0.8s ease-out forwards;
}

/* Star fly animation */
@keyframes starFly {
  0%   { transform: scale(0) translateY(0); opacity:1; }
  60%  { transform: scale(1.4) translateY(-60px); opacity:1; }
  100% { transform: scale(0.8) translateY(-120px); opacity:0; }
}