body {
    width: 50rem;
    margin: 5rem auto;
    color: #eee;
    background-color: #111;
    font-family: Open Sans, sans-serif;
}

#preview {
    display: flex;
    flex-direction: row;
    margin-bottom: 1rem;
}

.group {
    display: block;
    margin-bottom: 0.5rem;
}

.space {
    display: block;
    height: 1rem;
}

#error {
    margin-top: 1rem;
    color: red;
}

#error:empty + span {
    display: none;
}