How to make an adaptive background?

Question

css

Good afternoon everyone, I'm learning the science of website layout, and I have questions, so I ask you not to throw too many slippers =)
1) There are two blocks on the page, they are 1140px wide, how to properly implement the background for the entire width of the screen? I implemented it like this - https://codepen.io/polezhaevr/pen/bGeOvrd


2) I made a block with a search, it seems normal, BUT! Why doesn't it compress when the resolution is changed, while the other two compress? Also, I am attaching the code to the block with the search engine

https://codepen.io/polezhaevr/pen/bGeOvrd