Fixing gaps in 2-column posts display messes up 2-column widget at bottom

My posts are displayed in the classic 2-column layout (with a sidebar as a third column). The problem is that there are gaps in the 2 columns where there should be posts listed. I tried fixing it with the following CSS code (in Appearance-▸Custom CSS):

#content .row{
display:flex;
flex-wrap:wrap;
}

It works but it messes up the “news items” and “noteworthy items” widgets that I have at the bottom of the each page. Each widget has 2 columns. When I add the above-mentioned CSS code, it causes the widgets to become 1 columned.

Is there any way to fix the gaps in the posts listed in the columns without affecting my bottom widgets?

I’m not sure if this will help you but I created the widgets previously per these instructions:

https://wordpress.org/support/topic/how-to-add-new-content-section-to-home-page-only/

Thanks.

The page I need help with: [log in to see the link]