form {
    margin-left: auto;
    margin-right: auto;
    max-width: 540px;
}

form > div {
    margin-left: 8px;
    margin-right: 8px;
}

.badge  {
    font-size: 0.9em;
}

.btn:not(.btn-back) {
    min-width: 6.5em;
}

.card {
    margin-left: auto;
    margin-right: auto;
}

.card-title {
    margin-bottom: 0;
}

.text-footer {
    opacity: 0.2;
}