Is there custom code for mobile navigation?

Hello all, I'm currently operating on Brine 7.0, and while I like the template and all the customizations it has to offer I cannot modify the mobile navigation to my liking. Is there a code that would allow for a change from the Brine's hamburger menu to the drop down menu from Avenue? Thanks!

Add to Design > Custom CSS

div#mobileMenuLink>a:before {
    content: "\e030";
    font-family: 'squarespace-ui-font';
    font-size: 30px;
}
div#mobileMenuLink>a {
    font-size: 0 !important;
}