td  {
  width: 100px;
  height: 100px;
  text-align: center;
  background-color: white ;
  font-size: 500%;  
}
.vertical{
  border-left: 2px solid black;
  border-right: 2px solid black;
}
.horizontal{
  border-top: 2px solid black;
  border-bottom: 2px solid black;
}

.lemon,.cross{
  
}
table{
  margin-left: auto;
  margin-right: auto;
}
h2{
  text-align: center;
}