Elements in navigation moving on load

Hello, the global navigation on my site shifts slightly when loading a new page (for example, clicking the ‘about’ or ‘contact’ links in the global nav on the homepage). It only shows up on my published site and isn’t apparent on the read-only link below. I’m not sure why this is happening all of a sudden, though it may be that one of our editors changed something in the text…I don’t know. Can you help? Thanks in advance!


Here is my site Read-Only: LINK
(how to share your site Read-Only link)