#puzzle {
  position: relative;
  width: 600px;
  height: 300px;
  left:173px;
}

#piecePuzzle {
  position: absolute;
  width: 80px;
  height: 80px;
  left: 20px;
  top: 110px;
  cursor: grab;
  border: 2px solid white;
  border-radius: 6px;
  z-index:9999;
}

#slot {
  position: absolute;
  width: 80px;
  height: 80px;
  left: 300px; 
  top: 110px;
  background: rgba(0, 0, 0, 0.4);
  border: 2px dashed white;
  border-radius: 6px;
  z-index:9998;
}