Oops! So sorry about that. It is a horizontal menu that is going 100% across the page but the links are all to the left. I would like them to be flush right. Here is a link to the site, so far: http://spoonfrogclients.com/nfr2/
If I've correctly understood what is wanted, I would be inclined to try one of the following two ideas, unless someone finds a simpler solution.
1. Using Menu Builder Design > Menu > Properties to adjust the following items at various breakpoints -
(a) Margin: probably zero right margin, and enough left margin to push the menu wholly to the right;
(b) Padding: probably zero left padding, and enough right padding to keep menu items a little away from the right extremity.
The Max width adjustment on the same panel may also help.
2a. Using Menu Builder Design > Menu > Properties to centralise the menu items (ticking Auto for Margin);
2b. In RSD, styling the HTML element in which the Menu Builder body content is placed. At various breakpoints one would need to reduce the width so that the menu items covered the whole width of the HTML element, and adjust the Position to float it right.