.container-custom {
position: relative;
width: 100%;
height: 875px;
padding-top: 30%; /* 16:9 Aspect Ratio */ 19.5:9
display: block;
overflow: auto;
}
.responsive-iframe-custom {
position: absolute;
top: 0;
left: 0;
bottom: 0;
right: 0;
width: 80%;
height: 100%;
border: none;
margin: auto;
}

https://youtu.be/-_pgXUcXD6g
Hear what Mike Lapper, Head of Customer Experience, Cadent Gas, had to say about Vyn