.main {
    max-width: 450px;
    background: rgba(255, 255, 255, 1);
    border-top: 5px double rgb(0, 0, 0);
    border-left: 5px double rgb(0, 0, 0);
    border-right: 5px double rgb(0, 0, 0);
    border-bottom: 5px double rgb(0, 0, 0);
    filter: drop-shadow(5px 5px rgba(0, 0, 0, 0.25));
}