Customer mobile menu?

I put this question in another thread but might be lost there.

I am looking to have a specific menu for the mobile site - is this possible? The reason is that with the standard menu (using Colorway) I have a lot of menu and submenu items. On mobile this gives a really long list of items. I'd like the mobile menu to just list the top two levels. I know how to creat a custom menu. How do I get this to come up when viewed on mobile? Many thanks.

Edit: Meant "custom" not "customer"

 

Hello,

Paste this code in Custom CSS
Appearance > Theme Option > Styling Option > Custom CSS

Code:

#mobile_menu {
overflow-y: scroll;
height: 200px;
}

 

Thank you for your quick reply Gourav. I will give it a try.