**Fixes Issue #1109**
**Changes:**
- Added tailwind class `fixed` to navbar, preventing it from
"disappearing" on mobile.
**Impact:**
Improves mobile navigation by ensuring the navbar is always visible,
enhancing user experience.
**Testing:**
- Manual device testing
- Manual dev tools testing
**Screenshots:**

This PR fixes several guide styles to support dark mode
- fixes table header color
- fixes admonition background color and text
- sets inactive tabs color
- sets black text to white
This solves #1108
The user avatar content in the header is now populated with a htmx get request. The request object is used to show either the join link, avatar or no avatar icon.
Issue: #850
Now using proprietary styles for the user guide - not shared with docs. We are able to better isolate and fix issues with the user guide header without having to touch antora.
Fonts are set in site.css at a large base than we use. This resets it and now haeder fonts match. Body font is not quite as big either and matches the main site.
Now using proprietary styles for the user guide - not shared with docs. We are able to better isolate and fix issues with the user guide header without having to touch antora.