.overlay-container {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    height: 100%;
    width: 100%;
    background: rgba(0, 0, 0, .5);
    z-index: 100;
}

.overlay-body {
    content: '';
    display: block;
    position: fixed;
    top: 0;
    bottom: 0;
    left: 0;
    right: 0;
    width: 75%;
    height: 75%;
    margin: auto;
    z-index: 101;
}

.overlay-body iframe {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
}