Weird boldness discrepancy in Safari

Hi! So one of my clients brought up an issue she can only see in Safari.

If you open safari and go to her homepage here: (she teaches women's sexuality courses) you can see the problem by looking at the dropdown menu under "About" and the one under "Offerings"

Despite being the same type of elements with the same properties (at least as far as I can tell), these two elements look REALLY different. The Offerings submenu is clearly much bolder.

Any ideas?