🐛 Bug: Dark mode navbar shows stray black underline on hover after page load

Describe the bug

• In dark mode on https://json-schema.org/ the navbar items (e.g., Specification, Docs, Tools, Blog, Community) show unwanted black underline lines when hovered.

• This issue does not appear immediately on page load. It starts appearing after ~2–3 seconds once the website finishes loading styles/resources and we hower it few times.

• The underline looks like a rendering/glitch artifact rather than intended styling.

Screencast:

https://github.com/user-attachments/assets/69fa8841-36f3-41be-81ab-06a4e23b011a

Steps To Reproduce

1. Go to https://json-schema.org/
2. Enable dark mode (moon icon in navbar)
3. Wait 2–3 seconds after the page fully loads
4. Hover over navbar items like Specification, Blog, Community multipe times.
5. Observe thin black lines appearing under the text

Expected Behavior

Hovering over navbar items in dark mode should show the intended highlight/underline effect without any black glitch lines.

Screenshots

Attached Above.

Device Information [optional]

- OS:Ubuntu (latest)
- Browser: Brave
- version:

Are you working on this issue?

Yes

Do you think this work might require an [Architectural Decision Record (ADR)]? (significant or noteworthy)

No

Reproduce the issue on https://json-schema.org/ by enabling dark mode, waiting for the page to finish loading, and repeatedly hovering navbar items. Inspect the navbar's dark-mode hover styling and verify that the intended highlight appears without black underline artifacts.