How do I right justify a row?

[seanwoods]

In this Gist:
https://gist.github.com/seanwoods/89fafc5028d514407950

I want the "login" box to be right justified on the right hand side of the navbar. Currently it comes right after the navigation buttons.

If I apply text-align: right to the #login element it doesn't work; likely because the width of that element doesn't reach to the right side of the page.

In the "normal" world I would just float a div and be done with it; how can a similar effect be achieved with FlexGrid?

Thanks!