how do I remove part of a border?

Hi,

At the top of my blog there are two “vertical borders” I marked them in screenshot:
https://www.informationmarketingexpert.com/Images/top-borders.png

Can you tell me how to remove/hide these two without removing the entire border? I know they’re part of the body border, and created by this code:

#container
{
  border-left: 1px solid #000;
  border-right: 1px solid #000;
}

Can you give me code to input or edit to do that?

Here’s the website URL: https://www.informationmarketingexpert.com/test/
Here’s css file: https://www.informationmarketingexpert.com/styletest.css

Thanks!

(hopefully last question) ??