table {
  border-collapse: collapse;
  margin: auto;
}

td {
  width: 100px;
  height: 100px;
  border: 1px solid black;
  text-align: center;
  vertical-align: middle;
  font-size: 50px;
  font-weight: bold;
  cursor: pointer;
}

td:hover {
  background-color: #eee;
}