Stretch background to full screen width?

Question

css

Good afternoon!
I have a fixed-width parent container that has a full-page-width block inside it, how can I stretch the background of this div?

Answer 1

codepen.io/Q2art/pen/EVevNM

Answer 2

background-size: cover;

Answer 3

If a block with width: 100% has nothing but a background, then it would be more logical to make it a parent of a block with a fixed width and not suffer.