.pct75pct-container {
    position: relative;
    padding-bottom: 75%;
    padding-top: 35px;
    height: 0;
    overflow: hidden; /*I am a comment*/
}
.pct75pct-container-iframe {
    position: absolute;
    top:0;
    left: 0;
    width: 100%;
    height: 100%;
}