Quick and easy way to make your YouTube videos adjust automatically to the tab width across responsive screens - simply change the width to 100%! I kept my player height at 240 so that most, if not all videos will play back in proper proportions on even the smallest handheld device...
<iframe width="
100%" height="240" src="//www.youtube-nocookie.com/embed/32HiJHMRdqg?rel=0" frameborder="0" allowfullscreen=""></iframe></p>
You can see this video in a related product's tab at:
https://www.iowish.com*NOTE: while the video is initially stretched and cropped before being viewed, it plays back normally with black side-bars on wider display areas, and in my opinion it doesn't look bad to start with so it shouldn't affect customer perception.