Need help with unique page inside nav

Hey everybody ! I am build locally my site with Lithium theme ( change little bit stuff straight from partials.html and main.css) but right now I am stuck. I have menu with 4 list-item(localhost/page/list-item-name (md files)) and now I want one of them be different (I want make row columns) and I can’t understand how make it. I saw videos about sections and overriding partials but still don’t get it how implement it in code.

The structure of theme nav is: