body{
  background-color:#333333;
}
#board {
  width: 800px;
  margin: 50px auto;
}
.red {
  width: 100px;
  height: 100px;
background-color:crimson;
float: left;
}
.white {
  width: 100px;
  height: 100px;
background-color:gainsboro;
float: left;
}
.red, .white {
  width: 100px;
  height: 100px;
  float: left;
}