Improve Notification Badge Styling

[Abd-Standard]

Description

Standardize badge colors and spacing for consistent visual representation of notification states.

Acceptance Criteria
Badge styles are consistent.
Colors follow the design system.
Accessibility contrast passes.

[iredis]

@iredis has applied to work on this issue as part of the Stellar Wave Program's 7th wave.

I’d love to work on this issue because it’s a great opportunity to contribute, improve my skills, and deliver a meaningful solution while learning from the project.

ℹ️ Repo Maintainers: To accept this application, review their application or assign @iredis to this issue.