table {
    border-collapse: collapse;
    border: 3px solid black;
    width: 100%;
}

td {
    border: 1px solid black;
    text-align: center;
    padding: 10px;
    font-size: 20px;
}

th {
    border: 1px solid black;
    text-align: center;
    padding: 10px;
    font-size: 20px;
}