h1 {
    text-align: center;

}

table {
    border-collapse: collapse;
    border: 3px solid green;
    margin: 16px auto;

}

tr:nth-of-type(odd) {
    background-color: gainsboro;
}

td {
    padding: 3px 6px;
    border-collapse: collapse;
    border: 1.5px dashed green;
}