Thanks Mani. I should perhaps not assumed the issue was just depending on the background. See attaches screenshot. You might then understand the whole problem.
Or is that too, the template? I mean in this case I suspect not. (Yes I could publish smaller sized videos, but why, when that empty space under the VIDEO title is useless and looks bad.)
you can hide video title in backend custom field param. So it will show in left side.
i disabled it. Please check it.
if you need to increase width of video, use uikit class inside iframe class which render video good in mobile.
if you need custom development for video width, Please fill custom development form.