:root {
  --bg: #0f0f1a;
  --surface: #1a1a2e;
  --surface2: #16213e;
  --accent: #e94560;
  --accent2: #0f3460;
  --text: #eee;
  --text-dim: #888;
  --tile-radius: 12px;
  --gap: 4px;
}

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

body {
  font-family: 'Segoe UI', system-ui, -apple-system, sans-serif;
  background: var(--bg);
  color: var(--text);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 20px;
  overflow: hidden;
}

/* Header */
h1 {
  font-size: 2rem;
  margin-bottom: 4px;
  background: linear-gradient(135deg, var(--accent), #ff6b6b);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.subtitle {
  color: var(--text-dim);
  font-size: 0.85rem;
  margin-bottom: 20px;
}

/* Controls */
.controls {
  display: flex;
  gap: 12px;
  margin-bottom: 16px;
  flex-wrap: wrap;
  justify-content: center;
}

.controls button,
.controls select {
  padding: 8px 18px;
  border: none;
  border-radius: 8px;
  background: var(--surface2);
  color: var(--text);
  font-size: 0.9rem;
  cursor: pointer;
  transition: all 0.2s;
  outline: none;
}

.controls button:hover {
  background: var(--accent);
  transform: translateY(-1px);
}

.controls select {
  appearance: none;
  padding-right: 28px;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' fill='%23eee' viewBox='0 0 16 16'%3E%3Cpath d='M8 11L3 6h10z'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 10px center;
}

.controls select:focus {
  border: 1px solid var(--accent);
}

/* Stats */
.stats {
  display: flex;
  gap: 24px;
  margin-bottom: 16px;
  font-size: 1rem;
}

.stats span { color: var(--text-dim); }
.stats strong { color: var(--text); }

/* Board */
.board-container {
  position: relative;
}

.board {
  display: grid;
  gap: var(--gap);
  padding: var(--gap);
  background: var(--surface);
  border-radius: 16px;
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.4),
              inset 0 1px 0 rgba(255, 255, 255, 0.05);
  user-select: none;
  -webkit-user-select: none;
  touch-action: manipulation;
}

/* Tiles */
.tile {
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--tile-radius);
  font-weight: 700;
  cursor: pointer;
  transition: transform 0.15s ease, box-shadow 0.15s ease;
  position: relative;
  background: linear-gradient(145deg, var(--surface2), #1a1a3e);
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.3),
              inset 0 1px 0 rgba(255, 255, 255, 0.08);
}

.tile:not(.empty):hover {
  transform: scale(1.04);
  box-shadow: 0 4px 16px rgba(233, 69, 96, 0.3),
              inset 0 1px 0 rgba(255, 255, 255, 0.1);
}

.tile:not(.empty):active {
  transform: scale(0.97);
}

.tile.empty {
  background: transparent;
  box-shadow: none;
  cursor: default;
}

.tile.correct {
  background: linear-gradient(145deg, #1a3a2e, #16213e);
  box-shadow: 0 2px 8px rgba(0, 255, 100, 0.15),
              inset 0 1px 0 rgba(255, 255, 255, 0.08);
}

/* Win Overlay */
.win-overlay {
  position: fixed;
  top: 0; left: 0; right: 0; bottom: 0;
  background: rgba(0, 0, 0, 0.8);
  display: none;
  align-items: center;
  justify-content: center;
  flex-direction: column;
  z-index: 100;
  animation: fadeIn 0.3s;
}

.win-overlay.show { display: flex; }

.win-overlay h2 {
  font-size: 3rem;
  margin-bottom: 8px;
  animation: bounceIn 0.5s;
}

.win-overlay p {
  color: var(--text-dim);
  margin-bottom: 20px;
  font-size: 1.1rem;
}

.win-overlay button {
  padding: 12px 32px;
  border: none;
  border-radius: 10px;
  background: var(--accent);
  color: white;
  font-size: 1rem;
  cursor: pointer;
  transition: transform 0.2s;
}

.win-overlay button:hover {
  transform: scale(1.05);
}

/* Confetti */
.confetti {
  position: fixed;
  width: 10px;
  height: 10px;
  border-radius: 2px;
  z-index: 101;
  animation: confettiFall 3s ease-out forwards;
}

/* Animations */
@keyframes fadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}

@keyframes bounceIn {
  0% { transform: scale(0.3); opacity: 0; }
  50% { transform: scale(1.1); }
  100% { transform: scale(1); opacity: 1; }
}

@keyframes confettiFall {
  0% { transform: translateY(0) rotate(0deg); opacity: 1; }
  100% { transform: translateY(100vh) rotate(720deg); opacity: 0; }
}

/* Responsive */
@media (max-width: 480px) {
  h1 { font-size: 1.5rem; }
  .stats { gap: 16px; font-size: 0.9rem; }
}