Add click feedback and visited state for clickable cards

When clicking on cards in **New Chapters**, **New Projects**, or **Top Contributors**, there is no clear visual feedback indicating that the click was registered. Additionally, after navigating back, there is no visual indication that a card has already been visited.

This can make the interface feel unresponsive and makes it harder for users to track which items they have already explored while browsing multiple cards.

**Proposed solution:**
- Add an **active / pressed state** when a card is clicked (e.g., subtle background, scale, or shadow change)
- Add a **visited state** for cards that have already been opened so users can distinguish explored and unexplored items

**Alternatives considered:**
- Relying only on hover states (current behavior), which does not provide sufficient feedback
- Adding a loading indicator alone, which does not address visited state recognition

**Implementation:**
- [x] I am willing to work on implementing this

This change would apply consistently across card-based sections such as **New Chapters**, **New Projects**, and **Top Contributors**, and can likely be implemented using CSS and lightweight state handling without backend changes.