How to increase the width of this blog? (Width of the main body and widget)

Question

This is the link to the blog https://www.glamiva.com/2021/09/its-been-while.html

Issue:

1. I want the page size to occupied 100% of the screen instead of it is currently now. Can you show the code section that I need to edit?

I include the below image to make it easier to understand:

Answer 1

There is :

@media (min-width: 1200px){
  .container {
    width: 1170px;
  }
}

Set the same but with width: auto; or 100% to overwrite the basic rule