.board {
  width:  384px;
  height: 384px;
  margin: 50px;
  border: 15px solid #333;
}
.black {
  float: left;
  width: 48px;
  height: 48px;
  font-size: 30px;
  text-align: center;
  vertical-align: middle;
  background-color: #999;
}
.white {
  float: left;
  width: 48px;
  height: 48px;
  font-size: 30px;
  text-align: center;
  vertical-align: middle;
  background-color: #eee;
}