#interested {
    background-color: #c0c0c0;

    padding-top: 20px;
    padding-bottom: 20px;

    text-align: center;
    text-decoration: none;
}

@media screen and (max-width: 900px) {
    #interested {
        padding-top: 5px;
        padding-bottom: 5px;
    }
}