Reduce space in navigation (tablet)

Site URL: https://elephant-crane-cc3x.squarespace.com/

I would like to reduce the white space in my navigation only for tablets.

On Mobile it looks perfect so it would be great if it looks less or more the same.

Which CSS code can I use?

Thanks!

Add to Design > Custom CSS

div.container.header-menu-nav-item a {
    margin-top: 1.35vw;
    margin-bottom: 1.35vw;
}