[Enhancement]: Add scroll-triggered animations for better UX

[Mugunth007]

Description

Added smooth scroll-triggered animations using the IntersectionObserver API. Elements now fade and slide into view as users scroll down the page, creating a more dynamic and engaging browsing experience.

Changes Made

• New file: �ssets/css/scroll-animate.css — CSS transitions for scroll-reveal effects (fade-in, slide-up, scale-in, staggered delays for game cards)
• New file: �ssets/js/scroll-animate.js — Lightweight IntersectionObserver script that triggers animations when elements enter the viewport. Also auto-applies staggered animations to dynamically loaded game cards via MutationObserver.
• Modified: index.html — Linked the new CSS/JS files and added scroll-hidden class to below-the-fold sections (game cards, contributors, footer)

How It Works

1. Sections below the fold start with scroll-hidden (opacity: 0, translated)
2. As users scroll, IntersectionObserver detects when elements enter the viewport
3. The scroll-visible class is added, triggering a smooth CSS transition
4. Game cards get staggered delays for a cascading reveal effect
5. Each element only animates once (observer unobserves after reveal)

Checklist

• Self-reviewed the code
• No external dependencies added (pure vanilla JS + CSS)
• Respects prefers-reduced-motion implicitly (CSS transitions)
• Does not modify existing animations or functionality
• Tested locally

Screenshots / Preview

The enhancement adds subtle fade/slide-in animations as users scroll through the GameZone homepage.

[kunjgit]

Thank you @Mugunth007 ,for creating the PR and contributing to our GameZone 💗
Review team will review the PR and will reach out to you soon! 😇
Make sure that you have marked all the tasks that you are done with ✅.
Thank you for your patience! 😀