How can I change width of Tutorial Videos?

I have used the Tutorials Videos on my website, however, when I view on my mobile device, the videos don't auto adjust to the width of my device.

I also have youtube videos on my website, but these videos DO adjust on different devices.

Is there a way I can make the width 100% for the videos? I only see how you can set a specific PX width for the videos, but that doesn't help much for viewing on mobile.