body {
  margin: 0;
  background: black;
}

#app {
  user-select: none;

  /* 4:3 */
  width: 1920px;
  height: 1080px;

  margin: auto;
  background: url("img/bg.jpg");
  background-position: center;
  background-repeat: no-repeat;

  position: relative;
}

.cell {
  position: absolute;
  transform: translate(-50%, -50%);
  background-position: center;
  background-repeat: no-repeat;
  width: 110px;
  height: 110px;
}

.row .cell.visible {
  color: inherit;
}
.cell img {
}