The video.js player keeps its defined width even on mobile, meaning that the video might stretch outside the visible screen.
[[File:Exhaust_fan_smoke_test.mp4|border|640px]]
Setting the following CSS seems to fix it;
:not(.thumbinner) > .video-js.video-js:not(.vjs-fullscreen) {
display: inline-block;
vertical-align: initial;
max-width: 100%;
height: auto;
padding-bottom: 56.25%;
}
The padding is necessary to keep the video height from becoming 0. The value 56.25% is the percentage relation between height and width in 16:9 format. (It would be 75% is the video was 4:3).
So the padding percentage must be calculated based on the height/width ratio.