.video-container {
    position: relative;
    padding-bottom: 56.25%;
    padding-top: 30px; height: 0; overflow: hidden;
}
 
#mask {
    z-index: 5;
    position: absolute; 
    top: 0;
    left:0;
    width: 100%;
    height:100%;
    display: none;
}

.video-container iframe,
.video-container object,
.video-container embed {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
}