/* CSS Document */
.js-game {
  display: grid;
  grid-template-columns: repeat(10, 1fr);
  grid-template-rows: repeat(7, 1fr);
  gap: 5px;
  width: 100%;
  height: 100%;
  background-color: #fff;
  position: relative;
  cursor: move;
}
.js-game::before {
  content: "";
  width: 100%;
  height: 100%;
  background: linear-gradient(-45deg, #ff0000, #ff7f00, #ffff00, #00ff00, #0000ff, #4b0082, #8f00ff);
  position: absolute;
  top: 0;
  left: 0;
  z-index: 2;
  mix-blend-mode: color;
  opacity: 1;
}
.js-game-item {
  background-color: #eee;
  border: 2px solid #999;
  border-radius: 10px;
  position: relative;
  z-index: 1;
  transition: .3s;
}