Card Stack Cascade

*,
*::before,
*::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

:root {
  --bg: #070a12;
  --text: #f0f4fb;
  --muted: #8a95a8;
  --accent: #86e8ff;
  --neon-purple: #ae52ff;
}

html {
  background: var(--bg);
  color: var(--text);
  font-family: "Inter", "SF Pro Display", system-ui, sans-serif;
}
body {
  overflow-x: hidden;
}

.intro {
  min-height: 70vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: 2rem;
}

.eyebrow {
  font-size: 0.7rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.18em;
  color: var(--accent);
  margin-bottom: 1rem;
}

h1 {
  font-size: clamp(2.2rem, 6vw, 4rem);
  font-weight: 700;
  letter-spacing: -0.03em;
  background: linear-gradient(135deg, #fff, var(--accent), var(--neon-purple));
  background-clip: text;
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.subtitle {
  font-size: clamp(0.9rem, 2vw, 1.05rem);
  color: var(--muted);
  max-width: 460px;
  margin-top: 0.75rem;
  line-height: 1.6;
}

/* Stack section */
.stack-section {
  position: relative;
  min-height: 250vh;
}

.perspective-container {
  position: sticky;
  top: 0;
  height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  perspective: 1200px;
}

.card-stack {
  position: relative;
  width: 380px;
  height: 460px;
}

/* Cards */
.stack-card {
  position: absolute;
  inset: 0;
  will-change: transform, opacity;
}

.card-glass {
  width: 100%;
  height: 100%;
  background: linear-gradient(
    135deg,
    hsla(var(--hue, 200), 30%, 15%, 0.6),
    hsla(var(--hue, 200), 20%, 10%, 0.8)
  );
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border: 1px solid hsla(var(--hue, 200), 40%, 40%, 0.2);
  border-radius: 20px;
  padding: 2.5rem;
  display: flex;
  flex-direction: column;
  justify-content: center;
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.3), inset 0 1px 0 hsla(var(--hue, 200), 50%, 70%, 0.08);
}

.card-num {
  font-size: 3rem;
  font-weight: 700;
  line-height: 1;
  margin-bottom: 1rem;
  color: hsla(var(--hue, 200), 60%, 60%, 0.2);
}

.card-glass h3 {
  font-size: 1.3rem;
  font-weight: 600;
  margin-bottom: 0.6rem;
  color: hsl(var(--hue, 200) 70% 80%);
}

.card-glass p {
  font-size: 0.88rem;
  color: var(--muted);
  line-height: 1.55;
  margin-bottom: 1.2rem;
}

.card-tags {
  display: flex;
  gap: 0.4rem;
  flex-wrap: wrap;
}
.card-tags span {
  padding: 0.18rem 0.55rem;
  border-radius: 4px;
  font-size: 0.65rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  background: hsla(var(--hue, 200), 40%, 30%, 0.25);
  color: hsl(var(--hue, 200) 60% 70%);
}

/* Outro */
.outro {
  min-height: 50vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: 2rem;
}

.outro h2 {
  font-size: clamp(1.8rem, 4vw, 3rem);
  font-weight: 700;
  letter-spacing: -0.02em;
  margin-bottom: 1.5rem;
}

.btn-back {
  display: inline-block;
  padding: 0.7rem 2rem;
  border-radius: 999px;
  border: 1px solid rgba(134, 232, 255, 0.3);
  color: var(--accent);
  text-decoration: none;
  font: 600 0.85rem / 1 "Inter", system-ui, sans-serif;
  transition: all 0.25s ease;
}
.btn-back:hover {
  background: rgba(134, 232, 255, 0.08);
  border-color: var(--accent);
}

/* Reduced motion */
.reduced-motion .stack-card {
  opacity: 1 !important;
  transform: none !important;
}

@media (max-width: 640px) {
  .card-stack {
    width: 300px;
    height: 400px;
  }
  .card-glass {
    padding: 1.8rem;
  }
}

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

  const MotionPreference = {
    prefersReducedMotion() {
      return __mql.matches;
    },
    setOverride(value) {
      const reduced = Boolean(value);
      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 });
        } catch {}
      }
    },
    onChange(listener) {
      __listeners.add(listener);
      try {
        listener({
          reduced: __mql.matches,
          override: null,
          systemReduced: __mql.matches,
        });
      } catch {}
      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: "Card Stack Cascade",
  category: "scroll",
  tech: ["gsap", "scrolltrigger", "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");

window.addEventListener("motion-preference", (e) => {
  document.documentElement.classList.toggle("reduced-motion", e.detail.reduced);
  ScrollTrigger.refresh();
});

const cards = gsap.utils.toArray(".stack-card");
const total = cards.length;

// Initial stacked position: all centered, slight y offsets, increasing scale-down
cards.forEach((card, i) => {
  gsap.set(card, {
    y: i * -8,
    scale: 1 - (total - 1 - i) * 0.04,
    rotateX: 0,
    zIndex: i,
    opacity: i === total - 1 ? 1 : 0.6,
  });
});

if (!reduced) {
  const tl = gsap.timeline({
    scrollTrigger: {
      trigger: ".stack-section",
      start: "top top",
      end: "bottom bottom",
      scrub: 1,
    },
  });

  // Fan out: each card moves to its final position
  cards.forEach((card, i) => {
    const angle = (i - (total - 1) / 2) * 8; // spread angle
    const xOff = (i - (total - 1) / 2) * 120; // horizontal spread
    const yOff = Math.abs(i - (total - 1) / 2) * 30; // arc shape
    const rot = (i - (total - 1) / 2) * 4; // slight rotation

    tl.to(
      card,
      {
        x: xOff,
        y: yOff,
        rotateY: angle,
        rotateZ: rot,
        scale: 1,
        opacity: 1,
        zIndex: i,
        duration: 1,
        ease: "none",
      },
      0
    );
  });

  // Second phase: cards settle into a grid-like arrangement
  cards.forEach((card, i) => {
    const col = i % 3;
    const row = Math.floor(i / 3);
    const gridX = (col - 1) * 200;
    const gridY = row * 240 - 120;

    tl.to(
      card,
      {
        x: gridX,
        y: gridY,
        rotateY: 0,
        rotateZ: 0,
        rotateX: 0,
        scale: 0.85,
        duration: 1,
        ease: "none",
      },
      1
    );
  });
}

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

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

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Card Stack Cascade — stealthisdesign</title>
  <link rel="stylesheet" href="style.css">
    <script type="importmap">{"imports":{"gsap":"https://esm.sh/gsap@3.13.0","gsap/ScrollTrigger":"https://esm.sh/gsap@3.13.0/ScrollTrigger","gsap/SplitText":"https://esm.sh/gsap@3.13.0/SplitText","gsap/Flip":"https://esm.sh/gsap@3.13.0/Flip","gsap/ScrambleTextPlugin":"https://esm.sh/gsap@3.13.0/ScrambleTextPlugin","gsap/TextPlugin":"https://esm.sh/gsap@3.13.0/TextPlugin","gsap/all":"https://esm.sh/gsap@3.13.0/all","gsap/":"https://esm.sh/gsap@3.13.0/","lenis":"https://esm.sh/lenis@1.1.13/dist/lenis.mjs","three":"https://esm.sh/three@0.171.0","three/addons/":"https://esm.sh/three@0.171.0/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="intro">
    <span class="eyebrow">Demo 05</span>
    <h1>Card Stack Cascade</h1>
    <p class="subtitle">Cards start stacked and fan out with 3D transforms as you scroll. Glassmorphism panels with perspective depth.</p>
  </section>

  <section class="stack-section">
    <div class="perspective-container">
      <div class="card-stack" id="card-stack">
        <div class="stack-card" data-index="0" style="--hue: 200;">
          <div class="card-glass">
            <span class="card-num">01</span>
            <h3>Scroll Animations</h3>
            <p>Choreograph complex timelines driven by scroll position with GSAP ScrollTrigger.</p>
            <div class="card-tags"><span>gsap</span><span>scrolltrigger</span></div>
          </div>
        </div>
        <div class="stack-card" data-index="1" style="--hue: 260;">
          <div class="card-glass">
            <span class="card-num">02</span>
            <h3>3D WebGL Scenes</h3>
            <p>Build immersive particle tunnels, shader backgrounds, and product showcases with Three.js.</p>
            <div class="card-tags"><span>three.js</span><span>webgl</span></div>
          </div>
        </div>
        <div class="stack-card" data-index="2" style="--hue: 320;">
          <div class="card-glass">
            <span class="card-num">03</span>
            <h3>View Transitions</h3>
            <p>Seamless page transitions with shared-element morphing using the View Transitions API.</p>
            <div class="card-tags"><span>view-transitions</span><span>css</span></div>
          </div>
        </div>
        <div class="stack-card" data-index="3" style="--hue: 40;">
          <div class="card-glass">
            <span class="card-num">04</span>
            <h3>Canvas Effects</h3>
            <p>Bokeh particles, spotlights, noise overlays, and magnetic cursors with Canvas 2D.</p>
            <div class="card-tags"><span>canvas</span><span>vanilla-js</span></div>
          </div>
        </div>
        <div class="stack-card" data-index="4" style="--hue: 160;">
          <div class="card-glass">
            <span class="card-num">05</span>
            <h3>Motion Design</h3>
            <p>Shared tokens, easing systems, and accessibility-first motion primitives.</p>
            <div class="card-tags"><span>design-system</span><span>a11y</span></div>
          </div>
        </div>
      </div>
    </div>
  </section>

  <section class="outro">
    <h2>Stack complete.</h2>
    <a href="/" class="btn-back">Back to Showcase</a>
  </section>

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