.cover {
    position: absolute;
    height: 100%;
    width: 100%;
    top: 0;
    left: 0;
    background-color: rgba(0,0,0,0.5);
    z-index: 65000
}
.dialog {
    position: absolute;
    z-index: 65001;
    background-color: white;
}
.dialog iframe { width: 100%; height: 100%; border: 0; }