Fix Home Page Navbar Positioning

On the home page, make the navbar position: absolute; so that when the user scrolls down, the content can scroll under the navbar. This will make the navbar stay at the top of the page.

Start at the home page navbar and inspect its current positioning styles. Update the navbar positioning as requested, then verify by scrolling that the page content moves under it while the navbar stays at the top.

Written by the indexing model from the issue text.