fix dark mode color and padding for the tab item

[nathanArseneau]

There were inconsistencies between the margins of all tabs.
Dark mode colors where not consistent

Motivation and Context

Adding consistency in the UI

How Has This Been Tested?

Breaking Changes

No

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Documentation update

Checklist

• I have read the MCP Documentation
• My code follows the repository's style guidelines
• New and existing tests pass locally
• I have added appropriate error handling
• I have added or updated documentation as needed

Additional context

[cliffhall]

@nathanArseneau the inconsistent tab gap was fixed with #265. Maybe you can resolve the conflicts and just make this PR handle the dark mode colors?

[nathanArseneau]

Hello @cliffhall I removed the fix for the tab gap and resolved the conflicts