.center-form {
    width: 900px;
    max-width: 100%;
    margin: 0 auto;
    border: 1px solid #eaeaea !important;
    padding: 25px 25px 10px;
    box-shadow: 0 0 5px 3px #f1f1f1;
}

@media (min-width: 768px) {
    .center-form {
        padding: 40px 40px 10px;
    }
}