How to adjust the poster and your cover to the youtube video?

Question

YouTube

Hello! Can't get past the video bug. Website
There is a video on the main page. The cover is set by background'om + poster, well, to show your covers. How to achieve a universal solution so that the cover or the video container itself is the same size and nothing peeks out, even if the cover size is changed?
I tried doing

.videoWrapper {
  position: relative;
  padding-bottom: 56.25%;
  padding-top: 25px;
  height: 0;
}
.videoWrapper iframe {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
}

}

Does not help. I tried to calculate from the picture (cover). I created an object with the help of js new Image()and calculated by size, maybe the right solution, but it didn’t work because of crooked hands. I can't think of what to do.
When you click on the video thumbnails next to the main video, a window with the video appears, the same thing is there.
And the video grid, the covers are cut due to the small size.
Tell me please.

Answer 1

background-size: cover;