#modal-dialog {
    // visibility: hidden;
    color: white;
    max-width: 300px;
    margin-left: -125px;
    background-color: black;
    text-align: center;
    border-radius: 2px;
    padding: 16px; // TODO: 'rem' better?
    position: fixed;
    z-index: 1;
    left: 50%;
    bottom: 30px;
    box-shadow: -1px 1px 10px rgba(0, 0, 0, 0.3);
}

#modal-dialog.show {
    visibility: visible;
}