div#popup-message{
    background: #fff;
    border: 2px solid #666;
    text-align: center;
}
div#popup-window-content-popup-message{
    font-size: 24px;
    color: red;
}
.popup-window-dark div#popup-window-content-popup-message{
    font-size: 24px;
    color: green;
}