Describe the bug

The hamburger menu on the docs site needs a fix. It works when the screen width is fairly narrow, but otherwise just darkens the page without displaying the navigation menu options.

To Reproduce
Steps to reproduce the behavior:

1. Go to https://block.github.io/goose/
2. View on a "typical" desktop screen size
3. Click the hamburger menu (☰) in the top navigation bar.
   The page darkens but no menu appears.
4. Resize to make the screen more narrow and click the hamburger menu.
   At around 800-1000px wide, the navigation options do display.

Expected behavior
When clicked, the hamburger menu should always display a sidebar containing the navigation items (Quickstart, Docs, Tutorials, MCPs, Blog, Resources, Discord, GitHub).

Environment

• OS & Arch: Multiple (affects all platforms)
• Interface: Documentation website
• Version: Current production site
• Browser: Multiple browsers affected

Additional context
Goose thinks the breakpoint for mobile navigation is set too high for typical desktop usage in
documentation/src/css/custom.css (around line 340)