.mc-bg {
  position: absolute;
  inset: 0; /* top:0 left:0 width:100% height:100% */
  display: grid;
  z-index: 0; /* behind content inside .page */
  pointer-events: none;
}

.tile {
  width: 50px;
  height: 50px;
  background-size: cover;
  background-repeat: no-repeat;
  background-position: center;
}