✅ Enhancement: Highlight Active Navigation Link Based on Current Route

# ✅ Enhancement: Highlight Active Navigation Link Based on Current Route

## Description
### When a user navigates to any page (e.g., `/about`), the corresponding link in the navigation bar (**About**) should be highlighted in **green** (the ## theme color) to indicate the current active page.

## Current Behavior
- The navbar does **not** highlight the active link.
- Users have no visual clue which page they are currently on, unless they check the URL.

## Expected Behavior
- The active navigation item (e.g., **About**) should be visually distinguished — ideally using the same green color as the site's theme (`#A2E33E` or similar).
- This improves **navigation clarity** and **user experience**.