iframe#appointment-iframe {
    width: 1px;
    min-width: 100%;
    min-height: 620px;
    transition: height 0.5s ease-out 0s;
    -webkit-transition: height 0.5s ease-out 0s;
    -moz-transition: height 0.5s ease-out 0s;
    -o-transition: height 0.5s ease-out 0s;
}

.hidden {
    display: none;
}