My mobile nav menu won't stay

Design help General
1

Can’t for the life of me figure out what I did. The nav menu drops down and goes away.

https://preview.webflow.com/preview/cournotlee?utm_medium=preview_link&utm_source=designer&utm_content=cournotlee&preview=a53a2e721d5841b091d09b3674d2c72d&mode=preview

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