Sitcky Menu - Item Menu

I need to be able to make a small change in the style of the menu. Because each menu item consists of two words, I need them to appear on top of each other…
Should appear as… Nuestras Normativas
Caravanas Precios
I guess it will be necessary to include some line of code type @media (min-width: 1200px) {> li {
width: 100px! Important;
I’ve tried but it does not work, any suggestions.
Thank you

Attached image of how the menu should look. Thanks.