Flatiron Gallery - Space between projects

Site URL: http://nichowell.com

I'm trying to add spacing between my projects using the Flatiron Template. I grabbed the code from this question...

I'm hoping to use a black background and when I change the color to black in this code i end up with a white margin on the right side of screen. So it looks like the below. Any thoughts on how to remove that white margin or really just make sure it's black as well. Thanks. 

On 11/30/2021 at 2:27 AM, NicHow151 said:

Site URL: http://nichowell.com

I'm trying to add spacing between my projects using the Flatiron Template. I grabbed the code from this question...

I'm hoping to use a black background and when I change the color to black in this code i end up with a white margin on the right side of screen. So it looks like the below. Any thoughts on how to remove that white margin or really just make sure it's black as well. Thanks. 

 

use

#grid .item a {
    border: 16px solid #000;
}

Thank You. 

If I can ask one more question. That removed any margin on right side of the screen so now images are flush on right side but have a margin on the left side. Is there a way to keep the margin on right side so that it's even with left side?