check out page called “wonderqube”. about 1/4 the way down the page is a large black section with a video smack in the middle. works wonderfully in safari and chrome. in firefox it is invisible and cannot be accessed.
Attached are screen captures of SAFARI and FIREFOX.
After changing this, the video works for me in Firefox and Chrome. Since there is no nested elements that have a width dimension, Firefox and Chrome are not rendering any width to the background video.