Hi @hmn566!
This will involve making some changes in both the CSS and the JavaScript that runs the menu – too much code to paste into this thread!
Rather than copy and pasting the multiple different parts, here’s a link to a child theme that will do the trick. If you aren’t already using a child theme of your own, you can upload and activate this and you should be good to go – you might need to adjust some theme settings, widgets, and menus, as with any theme activation ??
Child theme download: https://cloudup.com/cTfOwjCmwo7