.card {
    margin: 0 auto; /* Added */
    float: none; /* Added */
    margin-bottom: 50px; /* Added */
    margin-top: 60px;
}

.hint{
    font-family: 'Open Sans', "Helvetica Neue", "Helvetica", Helvetica, Arial, sans-serif;
    font-weight: 200;
    font-style: italic;
    font-size: small;
}

.bg-dark1{
    background-color: #161510;
}