feat(nav-links): add hover and active color styles using --vt-c-indigo

[diptipradeep]

Partially resolves issue #1539

This PR implements hover and active color styles for the navigation links (.nav-links) in the portfolio.

Changes included:

• Nav links now change from grey to the --vt-c-indigo color on hover and when active.
• Ensures consistency with the portfolio's color palette and improves UI feedback.

Pending tasks (to be implemented in future PRs):

• Navigation bar layout and responsiveness (desktop + mobile)
• Hamburger menu toggle for mobile
• Button (.btn) styles with hover and accessibility effects
• Consistent spacing using --section-gap

This partial update ensures the navigation links visually respond to user interaction and maintains color consistency with the theme.
I will be working on the remaining tasks (responsive nav layout, hamburger toggle, button styles, and spacing) in separate PRs to resolve issue #1539 fully.
Thank you!

[diptipradeep]

@microsoft-github-policy-service agree

[diptipradeep]

Hello maintainers,
I have created this PR — “feat(nav-links): add hover and active color styles using --vt-c-indigo” — as part of Hacktoberfest 2025.
If it aligns with the project’s standards, could you kindly consider adding the hacktoberfest-accepted label?
Thank you !