table {
    border: double 6px black;
    margin:auto
}
tr{
    height: 80px;
}
td{
    width: 80px;
    text-align: center;
    font-size: 3em;
}
tr:nth-child(odd) td:nth-child(even){
    background-color: black;
    color: white;
}
tr:nth-child(even) td:nth-child(odd){
    background-color: black;
    color: white;
}
h1{
    text-align: center;
    font-family: 'Lucida Sans', 'Lucida Sans Regular', 'Lucida Grande', 'Lucida Sans Unicode', Geneva, Verdana, sans-serif;
    font-size: x-large;
}
form{
    text-align: center;
    height: 20px;
}