2048 Dark Theme Custom CSS

style.css

body {
  background:#000;
}

.grid-cell {
    background: #333;
    box-shadow: 0 0 10px inset #000;
}

.tile .tile-inner {
    box-shadow: inset 0 0 20px red;
}

.tile.tile-2 .tile-inner {
    box-shadow: inset 0 0 10px #999;
}

.tile.tile-4 .tile-inner {
  box-shadow: inset 0 0 10px #cc6b6b;
}

.tile.tile-128 .tile-inner {
  box-shadow: inset 0 0 10px #ff7100;
}

.tile.tile-1024 .tile-inner {
  background: #037043;
  color:#fff;
  box-shadow: inset 0 0 20px #00d0ff;
  text-shadow: 0 0 5px #41ffb6;
}

.tile.tile-2048 .tile-inner {
  background: #3a036b;
  color: #fff;
  box-shadow: inset 0 0 20px #509ef0;
  text-shadow: 0 0 6px #c4dcf7;
}

.tile.tile-4096 .tile-inner {
  background: #4e021f;
  color: #fff;
  box-shadow: inset 0 0 20px #f14747;
  text-shadow: 0 0 6px #ff0000;
}

.tile.tile-8192 .tile-inner {
    background: #1f4000;
    color: #fff;
    box-shadow: inset 0 0 10px #cdff00;
}

.game-container {
    background: #444;
}

#ucss-code-wrapper, #ucss-code-wrapper div {
  color:#000;
  background:#fff;
}

#ucss-code-wrapper div.ucss-panel {
  background:#000;
  color:#000;
}

#ucss-code-wrapper div.ucss-toggle {
  background:#f00;
  color:#000;
}