Hi there,
tricky to do that especially when Sub Menus are in play.
First off you would need to add some HTML to your menu item label so:
Model Portfolios
would become:
<div><span>Model </span><span>Portfolios</span></div>
Then give the Menu Item a CSS Class of two-line
This article explains how to add a class to the menu item:
https://docs.generatepress.com/article/using-the-wordpress-menu-builder/#custom-classes
Then we can use some CSS to change its layout for tablet/desktop:
@media(min-width: 769px) {
.main-navigation .main-nav ul li.two-line>a {
display: flex;
}
.main-navigation .main-nav ul li.two-line>a div {
display: flex;
flex-direction: column;
line-height: 1.2em;
justify-content: center;
}
}