:root {
  --primary: #2563eb;
  --bg-dark: #050505;
  --text: #ffffff;
  --panel: #121212;
  --panel-border: #2a2a2a;
}
* {
  box-sizing: border-box;
}
body {
  background: radial-gradient(circle at 20% 20%, #171717 0, var(--bg-dark) 55%);
  color: var(--text);
  font-family: 'Courier New', monospace;
  margin: 0;
  min-height: 100vh;
  touch-action: manipulation;
}
.game-shell {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 76px 16px 24px;
}
.screen {
  width: min(620px, 100%);
}
.hidden {
  display: none;
}
.card {
  border: 3px solid #0c0c0c;
  background: rgba(255, 255, 255, 0.94);
  border-radius: 16px;
  box-shadow: 0 16px 0 #0c0c0c;
  color: #0c0c0c;
  padding: 24px;
  text-align: center;
}
.card h1,
.card h2 {
  margin: 0 0 12px;
  color: var(--primary);
  text-transform: uppercase;
  text-shadow: 2px 2px #0c0c0c;
}
.card p {
  font-weight: 700;
  margin: 0 0 16px;
}
button {
  background: #2563eb;
  color: #ffffff;
  border: 3px solid #0c0c0c;
  font-weight: 700;
  cursor: pointer;
  padding: 12px 24px;
  font-size: 1rem;
  border-radius: 8px;
  font-family: inherit;
  box-shadow: 4px 4px 0 #0c0c0c;
  text-transform: uppercase;
}
button:active {
  transform: translate(4px, 4px);
  box-shadow: none;
}
.hud {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 8px;
  margin-bottom: 12px;
  padding: 14px;
  align-items: center;
}
.card-lite {
  border: 2px solid var(--panel-border);
  border-radius: 12px;
  background: #101010;
}
.hud div {
  font-size: 0.95rem;
}
.hud span {
  color: var(--primary);
  font-weight: 700;
}
#newGameButton {
  padding: 8px 10px;
  font-size: 0.8rem;
}
.grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 8px;
  background: #1a1a1a;
  border-radius: 8px;
  padding: 8px;
  touch-action: none;
  position: relative;
}
.board-wrap {
  position: relative;
}
.cell {
  aspect-ratio: 1;
  border-radius: 6px;
  background: #101010;
  border: 1px solid #2a2a2a;
  position: relative;
}
.tile {
  position: absolute;
  inset: 0;
  border-radius: 6px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: clamp(0.7rem, 3vw, 1.1rem);
  transition: transform 0.1s ease-out;
  will-change: transform;
}
.tile.slide-left {
  transform: translateX(-10px);
}
.tile.slide-right {
  transform: translateX(10px);
}
.tile.slide-up {
  transform: translateY(-10px);
}
.tile.slide-down {
  transform: translateY(10px);
}
.tile.new {
  animation: 120ms ease-out pop-in;
}
.tile.merge {
  animation: 120ms ease-out merge-pop;
}
@keyframes pop-in {
  0% {
    transform: scale(0.7);
    opacity: 0.6;
  }
  100% {
    transform: scale(1);
    opacity: 1;
  }
}
@keyframes merge-pop {
  0%,
  100% {
    transform: scale(1);
  }
  50% {
    transform: scale(1.1);
  }
}
.tile-dark {
  background: #2a2a2a;
  color: #f8f8f8;
}
.tile-green-1 {
  background: #172554;
  color: #dbeafe;
}
.tile-green-2 {
  background: #1e40af;
  color: #eff6ff;
}
.tile-gold-1 {
  background: #5a4a00;
  color: #fff6bf;
}
.tile-gold-2 {
  background: #8a7000;
  color: #fff6bf;
}
.tile-purple-1 {
  background: #3a1a5a;
  color: #f1d8ff;
}
.tile-purple-2 {
  background: #6a3a9a;
  color: #f1d8ff;
}
.tile-orange-1 {
  background: #5a2a00;
  color: #ffe6d1;
}
.tile-orange-2 {
  background: #9a5a00;
  color: #fff0dd;
}
.tile-unicorn {
  background: #2563eb;
  color: #ffffff;
}
.overlay {
  position: absolute;
  inset: 8px;
  margin: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  z-index: 5;
}
.overlay.hidden {
  display: none;
}
.overlay-actions {
  display: flex;
  justify-content: center;
  gap: 10px;
  flex-wrap: wrap;
}
.result-line {
  font-size: 1.1rem;
}
@media (max-width: 600px) {
  .game-shell {
    align-items: center;
    padding: 72px 16px;
  }
  .screen {
    width: min(420px, 100%);
  }
  .hud {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
  #newGameButton {
    grid-column: span 2;
  }
}