The navbar links should end up looking like this in the end, with the navbar’s full width intended to match the full width of the content: 2020-04-18_2032
Not your fault, that’s a long time bug: you can’t expect the Flexbox Justify rules to work well if the Flexbox element is a Webflow Container element.
But that’s ok: revert the Container from Flexbox to Block, put a div in the Container, put all the links in the div, make the div width 100%, and finally give Flexbox to the div and apply your — now working — Justify rule.