The mobile nav is too transparent, which affects readability

The mobile nav menu is too transparent and affects readability...👀
https://github.com/TanStack/tanstack.com/blob/main/src/components/Navbar.tsx#L565

<img width="300" alt="Image" src="https://github.com/user-attachments/assets/e467798c-0bb1-488e-b218-e5c3ffbbe8d0" />


