.table-calendar {
    max-width: 480px;
}
.table-calendar td.not-current-month {
    background-color: #f9f9f9;
    /* Color de fondo base */
    background-image: repeating-linear-gradient(-45deg,
            transparent,
            transparent 10px,
            #ebebeb 10px,
            /* Color de la raya */
            #ebebeb 20px);
}