Hello 
I'm new to PrestaShop (and to PHP aaaand to Smarty! 😅 ), I'm playing around with the Classic theme trying to adapt it in a child theme. I was able to use custom.css and also to override modules partially (with extends) or totally in this child theme.
But I'm having my first difficulties now, I would like to be able to split the mainmenu (header-top) in half, three items menu on the left and three on the right (numbers could change in the future) without impacting mainmenu in mobile. I found the ps_mainmenu module and understood the foreach loop through the nodes.
I reckon best way to achieve the split is to have two <ul> (with a float right on the second one) but I'm not sure. And I can't figure how to override the code to do that.
Hope I gave you enough informations and reaaally hope to find some help here. Thanks in advance.
Cheers