[izietto]

here with a yellow background (edit: changed to a yellow-to-green circle-shaped radial gradient because why not): https://codepen.io/mdesantis/pen/RwNZEZJ

[pbhjpbhj]

Maybe, https://codepen.io/pbhj/pen/dyPzwEj instead - centre the video and put the gradient on the body to emphasise the matting?