🐛 Bug - Incorrect 404 Page Display and CSS Issues

[JeanThirion]

Requested by: @JeanThirion via YakShaver.ai 🦬
cc: @JeanThirion, @Aibono1225, @Marxoz, @PothieuG, @Freego1783

Hi Team!

  🟥  Watch the video (1 min 7 sec)

  Url from screen share: https://www.ssw.com.au/rules-beta/rules

Pain

Fix the unexpected navigation to a 404 page when clicking on rules, correct the message displayed, and address CSS issues causing overlapping text and poor layout.

Acceptance Criteria

1. Clicking on 'rules' should not navigate to a 404 page unless the page is genuinely not found.
2. The 404 message should be clear and correctly formatted, with '404' prominently displayed in the center.
3. CSS should be adjusted to prevent overlapping text and ensure consistent spacing between lines.
4. The overall look and feel of the page should be improved to meet design standards.

Reproduce Steps

1. Navigate to the 'Rules V3 (TinaCMS)' section.
2. Click on 'rules' at the top of the page.
3. Observe the navigation to a 404 page and the incorrect message displayed.
4. Check the CSS for overlapping text and inconsistent spacing.

Screenshot

Figure: Unexpected A44 page and incorrect message on rules click

[PothieuG]

Also, it's weird that we are landing on that page as we already have another one that we implemented during the migration:
(Don't mind the margin, it's an old screenshot).

[Freego1783]

✅Done (don't mind the footer, it's been fixed in another PR)