🎨 Palette: Add tactile :active states to buttons and cards

[keough99]

💡 What: Added :active states to .btn and .social-card elements to complement their existing transform-based :hover states.
🎯 Why: To provide continuous, satisfying tactile feedback during interactions, preventing the elements from feeling unresponsive when clicked.
📸 Before/After: Before, buttons and cards only scaled or translated on hover, remaining static when clicked. After, they scale down slightly (scale(0.98)) or reduce translation (translateY(-2px)) when actively clicked.
♿ Accessibility: Improves visual feedback for interactive elements, aiding users with cognitive or visual impairments by clearly indicating when an action has been successfully triggered.

---

PR created automatically by Jules for task 7118819934099202915 started by @keough99

[google-labs-jules]

👋 Jules, reporting for duty! I'm here to lend a hand with this pull request.

When you start a review, I'll add a 👀 emoji to each comment to let you know I've read it. I'll focus on feedback directed at me and will do my best to stay out of conversations between you and other bots or reviewers to keep the noise down.

I'll push a commit with your requested changes shortly after. Please note there might be a delay between these steps, but rest assured I'm on the job!

For more direct control, you can switch me to Reactive Mode. When this mode is on, I will only act on comments where you specifically mention me with @jules. You can find this option in the Pull Request section of your global Jules UI settings. You can always switch back!

New to Jules? Learn more at jules.google/docs.

---

For security, I will only act on instructions from the user who triggered this task.