Would like help to improve parent child menu items display in Charm template

I would like to improve the line spacing of the submenu items now because they are not very attractive with the default spacing. What I would like to know how to do is to reduce the spacing between the child items so that they would appear a bit closer to their parent items. And, also increase the spacing between a parent item that is appearing below another parent item.

I have made a picture to hopefully be clearer in what I am hoping for.

I would love a little CSS tweak for this.

Sean