Navbar cuts the boat on mid/small screen resolutions

[Crsk]

While scrolling on the main page, navigation bar partially cuts the boat. This should only happen on certain screen resolutions, such as mine: Macbook pro built-in retina display 13,3-inch (2560 × 1600) at 100% zoom.

Increasing z-index seems to fix the issue.

https://github.com/helm/helm-www/assets/6186848/08c5dccf-2081-46d4-a2c8-8272396a2199