.preview-iframe-c{
    position: fixed;
    top:0; left: 0; right: 0; bottom: 0;
    background: rgba(0,0,0,0.8);
    z-index: 999999;
    padding: 50px;
    padding-bottom: 0;
}
.preview-iframe-c iframe{
    width: 100%; height: 100%;
    border: none;
    background: #fff;
}
.preview-iframe-c .preview-close{
    display: block;
    position: absolute;
    right: 15px; top: 15px;
    color: #fff !important;
    text-align: center;
    font-size: 30px;
    cursor: pointer;
}