Add the following CSS to the header block of your HTML document.

Then add the mark-up below to the body block of the same document.

<br /> .videoWrapper { <br /> position: relative; <br /> padding-bottom: 56.25%; <br /> padding-top: 25px; <br /> height: 0; <br /> } <br /> .videoWrapper iframe { <br /> position: absolute; <br /> top: 0; <br /> left: 0; <br /> width: 100%; <br /> height: 100%; <br /> }