tr:nth-child(even) {
    background-color: #D6EEEE;
}

.tableStyle1 td:nth-child(even) {
    background-color: #afafaf;
}

table, td, th {
    border: 1px solid black;
    border-collapse: collapse;
    vertical-align: middle;
    font-size: 18px;
    height: 60px;
}

/* RESET serial number for EACH table */
table {
    width: 100%;
    border-collapse: collapse;
    counter-reset: Serial;
}

/* auto serial numbering */
tr td:first-child::before {
    counter-increment: Serial;
    content: counter(Serial);
}