Parallax Depth Card Grid

if (!window.MotionPreference) {
  const __mql = window.matchMedia("(prefers-reduced-motion: reduce)");
  const __listeners = new Set();

  const MotionPreference = {
    prefersReducedMotion() {
      return __mql.matches;
    },
    setOverride(value) {
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      document.documentElement.classList.toggle("reduced-motion", reduced);
      window.dispatchEvent(new CustomEvent("motion-preference", { detail: { reduced } }));
      for (const listener of __listeners) {
        try {
          listener({ reduced, override: reduced, systemReduced: __mql.matches });
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    },
    onChange(listener) {
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        listener({
          reduced: __mql.matches,
          override: null,
          systemReduced: __mql.matches,
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      return () => __listeners.delete(listener);
    },
    getState() {
      return { reduced: __mql.matches, override: null, systemReduced: __mql.matches };
    },
  };

  window.MotionPreference = MotionPreference;
}

function prefersReducedMotion() {
  return window.MotionPreference.prefersReducedMotion();
}

function initDemoShell() {
  // No-op shim in imported standalone snippets.
}

import gsap from 'gsap';
import { ScrollTrigger } from 'gsap/ScrollTrigger';
import Lenis from 'lenis';

gsap.registerPlugin(ScrollTrigger);

initDemoShell({ title: 'Parallax Depth Card Grid', category: 'scroll', tech: ['gsap', 'scrolltrigger', 'css-3d-transforms'] });

const lenis = new Lenis({ lerp: 0.1, smoothWheel: true });
lenis.on('scroll', ScrollTrigger.update);
gsap.ticker.add((time) => lenis.raf(time * 1000));
gsap.ticker.lagSmoothing(0);

const reduced = prefersReducedMotion();
if (reduced) document.documentElement.classList.add('reduced-motion');

// Intro animation
if (!reduced) {
  gsap.set('.hero .eyebrow', { opacity: 0, y: 20 });
  gsap.set('.hero h1', { opacity: 0, y: 40 });
  gsap.set('.hero .subtitle', { opacity: 0, y: 25 });

  gsap.timeline({ defaults: { ease: 'expo.out' } })
    .to('.hero .eyebrow', { opacity: 1, y: 0, duration: 0.7, delay: 0.3 })
    .to('.hero h1', { opacity: 1, y: 0, duration: 0.9 }, '-=0.4')
    .to('.hero .subtitle', { opacity: 1, y: 0, duration: 0.7 }, '-=0.5');
}

// Card entrance animations with depth stagger
const cards = document.querySelectorAll('.card');
cards.forEach((card) => {
  const depth = parseFloat(card.style.getPropertyValue('--depth')) || 0.5;
  const index = parseInt(card.style.getPropertyValue('--index'), 10) || 0;

  // Initial state
  gsap.set(card, {
    opacity: 0,
    y: 80,
    scale: 0.8,
    rotationY: -15,
    rotationX: 10,
  });

  if (!reduced) {
    // Entrance animation with depth-based delay
    gsap.to(card, {
      opacity: 1,
      y: 0,
      scale: 1,
      rotationY: 0,
      rotationX: 0,
      duration: 1,
      ease: 'expo.out',
      delay: depth * 0.3, // Depth determines stagger
      scrollTrigger: {
        trigger: '.cards-container',
        start: 'top 70%',
        toggleActions: 'play none none reverse',
      },
    });

    // Hover lift effect
    card.addEventListener('mouseenter', () => {
      gsap.to(card, {
        y: -20,
        boxShadow: '0 30px 60px rgba(134, 232, 255, 0.2)',
        duration: 0.4,
        overwrite: 'auto',
      });
    });

    card.addEventListener('mouseleave', () => {
      gsap.to(card, {
        y: 0,
        boxShadow: '0 10px 30px rgba(0, 0, 0, 0.3)',
        duration: 0.4,
        overwrite: 'auto',
      });
    });
  }
});

// Parallax depth during scroll
if (!reduced) {
  gsap.to('.cards-grid', {
    scrollTrigger: {
      trigger: '.cards-container',
      start: 'top center',
      end: 'bottom center',
      scrub: 1,
      onUpdate: (self) => {
        cards.forEach((card, i) => {
          const depth = parseFloat(card.style.getPropertyValue('--depth')) || 0.5;
          const offset = self.progress * depth * 50; // Parallax amount
          gsap.set(card, { y: offset, overwrite: 'auto' });
        });
      },
    },
  });
}

// Details section reveals
document.querySelectorAll('.details h2, .details h3, .details p, .details ul').forEach((el) => {
  if (!reduced) {
    gsap.set(el, { opacity: 0, y: 30 });
    gsap.to(el, {
      opacity: 1,
      y: 0,
      duration: 0.7,
      ease: 'expo.out',
      scrollTrigger: {
        trigger: el,
        start: 'top 75%',
        toggleActions: 'play none none reverse',
      },
    });
  }
});

// List items
document.querySelectorAll('.details ul li').forEach((li, i) => {
  if (!reduced) {
    gsap.set(li, { opacity: 0, x: -20 });
    gsap.to(li, {
      opacity: 1,
      x: 0,
      duration: 0.6,
      ease: 'expo.out',
      delay: 0.05 * i,
      scrollTrigger: {
        trigger: li,
        start: 'top 75%',
        toggleActions: 'play none none reverse',
      },
    });
  }
});

// Motion preference listener
window.addEventListener('motion-preference', (e) => {
  if (e.detail.reduced) {
    gsap.globalTimeline.paused(true);
  } else {
    gsap.globalTimeline.paused(false);
  }
});

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Parallax Depth Card Grid — stealthisdesign</title>
  <link rel="stylesheet" href="style.css">
    <script type="importmap">{"imports":{"gsap":"/vendor/gsap/index.js","gsap/ScrollTrigger":"/vendor/gsap/ScrollTrigger.js","gsap/SplitText":"/vendor/gsap/SplitText.js","gsap/Flip":"/vendor/gsap/Flip.js","gsap/ScrambleTextPlugin":"/vendor/gsap/ScrambleTextPlugin.js","gsap/TextPlugin":"/vendor/gsap/TextPlugin.js","gsap/all":"/vendor/gsap/all.js","gsap/":"/vendor/gsap/","lenis":"/vendor/lenis/dist/lenis.mjs","three":"/vendor/three/build/three.module.js","three/addons/":"/vendor/three/examples/jsm/"}}</script>
  <style>html.lenis,
html.lenis body {
  height: auto;
}

.lenis:not(.lenis-autoToggle).lenis-stopped {
  overflow: clip;
}

.lenis [data-lenis-prevent],
.lenis [data-lenis-prevent-wheel],
.lenis [data-lenis-prevent-touch] {
  overscroll-behavior: contain;
}

.lenis.lenis-smooth iframe {
  pointer-events: none;
}

.lenis.lenis-autoToggle {
  transition-property: overflow;
  transition-duration: 1ms;
  transition-behavior: allow-discrete;
}</style>
</head>
<body>
  <section class="hero">
    <div class="content">
      <span class="eyebrow">Demo 38</span>
      <h1>Parallax Depth Card Grid</h1>
      <p class="subtitle">Cards positioned at different depth layers, staggered entrance with perspective. Creates a cinematic 3D effect without using WebGL.</p>
    </div>
  </section>

  <section class="cards-container">
    <div class="cards-grid">
      <div class="card" style="--depth: 0.8; --index: 0;">
        <div class="card-inner">
          <div class="card-icon">◆</div>
          <h3>Strategic Vision</h3>
          <p>Cards recede into the distance with layered transforms, creating depth.</p>
        </div>
      </div>

      <div class="card" style="--depth: 0.6; --index: 1;">
        <div class="card-inner">
          <div class="card-icon">▲</div>
          <h3>Cinematic Feel</h3>
          <p>Rotation and scale based on depth position for premium impression.</p>
        </div>
      </div>

      <div class="card" style="--depth: 0.4; --index: 2;">
        <div class="card-inner">
          <div class="card-icon">●</div>
          <h3>Smooth Stagger</h3>
          <p>Each card enters in sequence with customized delay and easing.</p>
        </div>
      </div>

      <div class="card" style="--depth: 0.7; --index: 3;">
        <div class="card-inner">
          <div class="card-icon">■</div>
          <h3>Responsive</h3>
          <p>Parallax depth scales gracefully on mobile without performance hit.</p>
        </div>
      </div>

      <div class="card" style="--depth: 0.5; --index: 4;">
        <div class="card-inner">
          <div class="card-icon">✦</div>
          <h3>Hover Interaction</h3>
          <p>Cards lift forward on hover, responding to mouse position.</p>
        </div>
      </div>

      <div class="card" style="--depth: 0.9; --index: 5;">
        <div class="card-inner">
          <div class="card-icon">◈</div>
          <h3>CSS 3D Transforms</h3>
          <p>Pure CSS perspective without JavaScript for depth effects.</p>
        </div>
      </div>
    </div>
  </section>

  <section class="details">
    <div class="content">
      <h2>How It Works</h2>
      <p>Each card has a <code>--depth</code> CSS variable that controls its position in 3D space. GSAP animates:</p>
      <ul>
        <li><strong>Transform:</strong> scaleZ, translateZ for depth positioning</li>
        <li><strong>Opacity:</strong> Cards closer to viewer are more opaque</li>
        <li><strong>Blur:</strong> Optional blur increases with distance (atmospheric perspective)</li>
        <li><strong>Delay:</strong> Each card stagger is calculated from its depth value</li>
      </ul>

      <h3>Technique Stack</h3>
      <p>This uses CSS 3D transforms with <code>perspective</code> container, GSAP for entrance choreography, and ScrollTrigger for scroll-based reveal. Hover states add interactivity.</p>

      <a href="/" class="btn-back">Back to Showcase</a>
    </div>
  </section>

  <script type="module" src="script.js"></script>
</body>
</html>