Hamburger and projects not working on mobile

Describe the bug I recently published and deployed a Hugo site that includes a Projects section. On my laptop the site works as expected. But when I view the site on my mobile device, neither the hamburger menu nor the ability to bring up information about individual projects works. When I click on the hamburger icon or one of the project headings on mobile the text turns from blue to black but nothing else happens.

To Reproduce Steps to reproduce the behavior:

1. Go to http://gcbumpy.com/ on a mobile device
2. Click on the hamburger icon or one of the five listed projects

Expected behavior When I access the site on my laptop via Chrome or Safari and make the browser window narrow to approximate the display on mobile, these two features of the site work as expected. When I click on the hamburger icon, it brings up a menu with a clickable list featuring the sections of the page. When I click on a project heading or thumbnail, it brings up a title, image carousel, and description of the project. I expected the same functionality on mobile.

Screenshots

Desktop:

• OS: macOS Monterrey 12.14
• Browser: Chrome
• Version: 114.0.5735.198 (Official Build) (arm64)

Smartphone:

• Device: iPhone 12
• OS: iOS 16.5.1
• Browser: Chrome
• Version: 108.0.5359.52

Additional context I am new to Hugo so I could be missing something obvious here! This is only my second Hugo site and my first using the Introduction theme. When I view the Hugo Netlify site linked from this GitHub repo on mobile I encounter the same problem (see the fifth screenshot). But I also see broken image links so perhaps this demo is no longer being maintained? Thanks so much for any help folks can offer!