body {
  position: relative;
  margin: 0;
  padding: 1.5vmin;
  background-color: rgb(187, 173, 160);
}
.board {
  margin: 0;
  padding: 0;
  display: block;
  width: 97vmin;
  height: 97vmin;
}
.cell {
  float: left;
  width: 21.25vmin;
  height: 21.25vmin;
  background-color: #ddd;
  margin: 1.5vmin;
  border-radius: 1vmin;
  /* border: 1px solid black; */
  line-height: 21.25vmin;
  text-align: center;

  color: rgb(119, 110, 101);
  background-color: rgba(238, 228, 218, 0.35);
  font-family: monospace;
  font-size: 5vmin;
  font-weight: 900;
}
#game-over {
  display: none;
  position: absolute;
  top: 1.5vmin;
  left: 1.5vmin;
  width: 97vmin;
  height: 97vmin;
  background-color: rgba(255, 255, 255, 0.5);
  font-size: 8vmin;
  text-align: center;
  line-height: 97vmin;
}