Vanilla JS App Enhancement

I need a seasoned Vanilla JS developer to integrate Google Single Sign-On into my app, fix the issues with the side navigation, and implement collapsible sections in the sidenav.

Key Tasks:
- Integrate Google authentication for a seamless Single Sign-On experience.
- Troubleshoot and rectify layout problems in the sidenav.
- Fix broken navigation links in the sidenav.
- Upgrade the sidenav to include collapsible sections.

Ideal Skills and Experience:
- Proficient in Vanilla JS with a strong portfolio of similar projects.
- Experience with Google authentication integration.
- Strong problem-solving skills for UI/UX issues.
- Familiarity with creating interactive, user-friendly components.