Card Grid Transition

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

:root {
  --bg: #070a12;
  --panel: #121a2b;
  --border: #263249;
  --text: #f0f4fb;
  --muted: #8a95a8;
  --accent: #86e8ff;
}

body {
  background: var(--bg);
  color: var(--text);
  font-family: "Inter", "SF Pro Display", system-ui, sans-serif;
  min-height: 100vh;
  overflow-x: hidden;
}

/* ── Views ── */
.view {
  display: none;
  min-height: 100vh;
}

.view.active {
  display: block;
}

/* ── Page header ── */
.page-header {
  text-align: center;
  padding: 5rem 2rem 2rem;
}

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

h1 {
  font-size: clamp(2rem, 5vw, 3.5rem);
  font-weight: 700;
  letter-spacing: -0.02em;
}

.subtitle {
  font-size: clamp(0.9rem, 2vw, 1.05rem);
  color: var(--muted);
  max-width: 480px;
  margin: 0.75rem auto 0;
  line-height: 1.6;
}

/* ── Card grid ── */
.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 1.25rem;
  max-width: 960px;
  margin: 2rem auto;
  padding: 0 2rem 4rem;
}

.card {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 14px;
  overflow: hidden;
  cursor: pointer;
  transition: transform 0.3s ease, border-color 0.3s ease, box-shadow 0.3s ease;
}

.card:hover {
  transform: translateY(-4px);
  border-color: rgba(134, 232, 255, 0.3);
  box-shadow: 0 8px 32px rgba(134, 232, 255, 0.06);
}

.card-visual {
  position: relative;
  height: 180px;
  overflow: hidden;
}

.card-image {
  width: 100%;
  height: 100%;
  background: linear-gradient(
    135deg,
    hsl(var(--hue, 200) 60% 15%),
    hsl(var(--hue, 200) 80% 25%),
    hsl(calc(var(--hue, 200) + 40) 70% 20%)
  );
  display: flex;
  align-items: center;
  justify-content: center;
}

.card-number {
  font-size: 3rem;
  font-weight: 700;
  color: rgba(255, 255, 255, 0.15);
  letter-spacing: -0.03em;
}

.card-body {
  padding: 1.25rem;
}

.card-body h3 {
  font-size: 1.05rem;
  font-weight: 600;
  margin-bottom: 0.5rem;
}

.card-body p {
  font-size: 0.85rem;
  color: var(--muted);
  line-height: 1.5;
}

/* ── Detail view ── */
.detail-layout {
  display: grid;
  grid-template-columns: 1fr 1fr;
  min-height: 100vh;
}

.detail-image-area {
  position: sticky;
  top: 0;
  height: 100vh;
  overflow: hidden;
}

.detail-image {
  width: 100%;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
  background: linear-gradient(135deg, hsl(200 60% 15%), hsl(200 80% 25%), hsl(240 70% 20%));
}

.detail-number {
  font-size: 8rem;
  font-weight: 700;
  color: rgba(255, 255, 255, 0.1);
  letter-spacing: -0.03em;
}

.detail-content {
  padding: 4rem 3rem;
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}

.back-btn {
  align-self: flex-start;
  background: none;
  border: 1px solid var(--border);
  border-radius: 8px;
  color: var(--accent);
  padding: 0.5rem 1rem;
  font: 600 0.8rem / 1 "Inter", system-ui, sans-serif;
  cursor: pointer;
  transition: border-color 0.25s, background 0.25s;
}

.back-btn:hover {
  border-color: var(--accent);
  background: rgba(134, 232, 255, 0.06);
}

.detail-title {
  font-size: clamp(2rem, 4vw, 3rem);
  font-weight: 700;
  letter-spacing: -0.02em;
  line-height: 1.1;
}

.detail-desc {
  font-size: 1.1rem;
  color: var(--muted);
  line-height: 1.6;
}

.detail-meta {
  display: flex;
  gap: 0.5rem;
  flex-wrap: wrap;
}

.meta-tag {
  padding: 0.25rem 0.7rem;
  background: rgba(134, 232, 255, 0.1);
  border: 1px solid rgba(134, 232, 255, 0.2);
  border-radius: 6px;
  font-size: 0.72rem;
  font-weight: 600;
  color: var(--accent);
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

.detail-body {
  font-size: 0.95rem;
  color: var(--muted);
  line-height: 1.7;
}

.detail-body code {
  background: rgba(134, 232, 255, 0.1);
  padding: 0.15rem 0.4rem;
  border-radius: 4px;
  font-size: 0.85rem;
  color: var(--accent);
}

/* ── View Transition styles ── */
::view-transition-old(root) {
  animation: fade-out 0.25s ease-out;
}

::view-transition-new(root) {
  animation: fade-in 0.25s ease-in;
}

::view-transition-group(card-image-1),
::view-transition-group(card-image-2),
::view-transition-group(card-image-3),
::view-transition-group(card-image-4),
::view-transition-group(card-image-5),
::view-transition-group(card-image-6) {
  animation-duration: 0.4s;
  animation-timing-function: cubic-bezier(0.4, 0, 0.2, 1);
}

::view-transition-group(card-title-1),
::view-transition-group(card-title-2),
::view-transition-group(card-title-3),
::view-transition-group(card-title-4),
::view-transition-group(card-title-5),
::view-transition-group(card-title-6) {
  animation-duration: 0.35s;
  animation-timing-function: cubic-bezier(0.4, 0, 0.2, 1);
}

@keyframes fade-out {
  from {
    opacity: 1;
  }
  to {
    opacity: 0;
  }
}

@keyframes fade-in {
  from {
    opacity: 0;
  }
  to {
    opacity: 1;
  }
}

/* ── Fallback for no View Transitions ── */
.no-vt .view {
  transition: opacity 0.3s ease;
}

/* ── Responsive ── */
@media (max-width: 768px) {
  .detail-layout {
    grid-template-columns: 1fr;
  }

  .detail-image-area {
    position: relative;
    height: 50vh;
  }

  .detail-content {
    padding: 2rem 1.5rem;
  }

  .card-grid {
    grid-template-columns: 1fr;
    padding: 0 1rem 3rem;
  }
}

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.
}

// ── Demo shell ──
initDemoShell({
  title: "Card Grid Transition",
  category: "transitions",
  tech: ["view-transitions-api", "css"],
});

// ── Check support ──
const supportsVT = typeof document.startViewTransition === "function";
if (!supportsVT) {
  document.body.classList.add("no-vt");
}

// ── Card data ──
const cardData = {
  1: {
    title: "Kinetic Typography",
    desc: "Motion-driven text that responds to scroll, time, and user interaction.",
    hue: 200,
  },
  2: {
    title: "Particle Systems",
    desc: "Thousands of elements choreographed into flowing, organic formations.",
    hue: 270,
  },
  3: {
    title: "Scroll Choreography",
    desc: "Precisely timed sequences that unfold as the user scrolls through content.",
    hue: 330,
  },
  4: {
    title: "Shader Art",
    desc: "GPU-powered visuals that create mesmerizing patterns in real-time.",
    hue: 45,
  },
  5: {
    title: "3D Environments",
    desc: "Immersive three-dimensional spaces built with WebGL and Three.js.",
    hue: 160,
  },
  6: {
    title: "Magnetic Interactions",
    desc: "Elements that attract, repel, and respond to cursor proximity with spring physics.",
    hue: 15,
  },
};

// ── DOM refs ──
const gridView = document.getElementById("grid-view");
const detailView = document.getElementById("detail-view");
const detailImage = document.getElementById("detail-image");
const detailNumber = document.getElementById("detail-number");
const detailTitle = document.getElementById("detail-title");
const detailDesc = document.getElementById("detail-desc");
const backBtn = document.getElementById("back-btn");

let currentId = null;

// ── Navigate to detail ──
function showDetail(id) {
  const data = cardData[id];
  if (!data) return;

  currentId = id;

  const updateDOM = () => {
    // Set view-transition-name on detail elements to match the card
    detailImage.style.viewTransitionName = `card-image-${id}`;
    detailTitle.style.viewTransitionName = `card-title-${id}`;

    // Update detail content
    detailImage.style.background = `linear-gradient(135deg, hsl(${data.hue} 60% 15%), hsl(${data.hue} 80% 25%), hsl(${data.hue + 40} 70% 20%))`;
    detailNumber.textContent = String(id).padStart(2, "0");
    detailTitle.textContent = data.title;
    detailDesc.textContent = data.desc;

    // Clear view-transition-name on the card's elements so they don't conflict
    const cardImage = document.querySelector(`[data-id="${id}"] .card-image`);
    const cardTitle = document.querySelector(`[data-id="${id}"] h3`);
    if (cardImage) cardImage.style.viewTransitionName = "none";
    if (cardTitle) cardTitle.style.viewTransitionName = "none";

    // Swap views
    gridView.classList.remove("active");
    detailView.classList.add("active");
  };

  if (supportsVT && !prefersReducedMotion()) {
    document.startViewTransition(updateDOM);
  } else {
    updateDOM();
  }
}

// ── Navigate back to grid ──
function showGrid() {
  const id = currentId;

  const updateDOM = () => {
    // Restore view-transition-name on original card elements
    if (id) {
      const cardImage = document.querySelector(`[data-id="${id}"] .card-image`);
      const cardTitle = document.querySelector(`[data-id="${id}"] h3`);
      if (cardImage) cardImage.style.viewTransitionName = `card-image-${id}`;
      if (cardTitle) cardTitle.style.viewTransitionName = `card-title-${id}`;
    }

    // Clear detail transition names
    detailImage.style.viewTransitionName = "none";
    detailTitle.style.viewTransitionName = "none";

    // Swap views
    detailView.classList.remove("active");
    gridView.classList.add("active");

    currentId = null;
  };

  if (supportsVT && !prefersReducedMotion()) {
    document.startViewTransition(updateDOM);
  } else {
    updateDOM();
  }
}

// ── Event listeners ──
document.querySelectorAll(".card").forEach((card) => {
  card.addEventListener("click", () => {
    const id = card.dataset.id;
    showDetail(id);
  });
});

backBtn.addEventListener("click", showGrid);

// ── Keyboard navigation ──
document.addEventListener("keydown", (e) => {
  if (e.key === "Escape" && detailView.classList.contains("active")) {
    showGrid();
  }
});

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Card Grid Transition — stealthisdesign</title>
  <link rel="stylesheet" href="style.css">
  </head>
<body>
  <!-- Grid View -->
  <div id="grid-view" class="view active">
    <header class="page-header">
      <span class="eyebrow">Demo 11</span>
      <h1>Card Grid Transition</h1>
      <p class="subtitle">Click any card to see a shared-element View Transition to the detail page.</p>
    </header>

    <div class="card-grid">
      <article class="card" data-id="1">
        <div class="card-visual" style="--hue: 200;">
          <div class="card-image" style="view-transition-name: card-image-1;">
            <span class="card-number">01</span>
          </div>
        </div>
        <div class="card-body">
          <h3 style="view-transition-name: card-title-1;">Kinetic Typography</h3>
          <p>Motion-driven text that responds to scroll, time, and user interaction.</p>
        </div>
      </article>

      <article class="card" data-id="2">
        <div class="card-visual" style="--hue: 270;">
          <div class="card-image" style="view-transition-name: card-image-2;">
            <span class="card-number">02</span>
          </div>
        </div>
        <div class="card-body">
          <h3 style="view-transition-name: card-title-2;">Particle Systems</h3>
          <p>Thousands of elements choreographed into flowing, organic formations.</p>
        </div>
      </article>

      <article class="card" data-id="3">
        <div class="card-visual" style="--hue: 330;">
          <div class="card-image" style="view-transition-name: card-image-3;">
            <span class="card-number">03</span>
          </div>
        </div>
        <div class="card-body">
          <h3 style="view-transition-name: card-title-3;">Scroll Choreography</h3>
          <p>Precisely timed sequences that unfold as the user scrolls through content.</p>
        </div>
      </article>

      <article class="card" data-id="4">
        <div class="card-visual" style="--hue: 45;">
          <div class="card-image" style="view-transition-name: card-image-4;">
            <span class="card-number">04</span>
          </div>
        </div>
        <div class="card-body">
          <h3 style="view-transition-name: card-title-4;">Shader Art</h3>
          <p>GPU-powered visuals that create mesmerizing patterns in real-time.</p>
        </div>
      </article>

      <article class="card" data-id="5">
        <div class="card-visual" style="--hue: 160;">
          <div class="card-image" style="view-transition-name: card-image-5;">
            <span class="card-number">05</span>
          </div>
        </div>
        <div class="card-body">
          <h3 style="view-transition-name: card-title-5;">3D Environments</h3>
          <p>Immersive three-dimensional spaces built with WebGL and Three.js.</p>
        </div>
      </article>

      <article class="card" data-id="6">
        <div class="card-visual" style="--hue: 15;">
          <div class="card-image" style="view-transition-name: card-image-6;">
            <span class="card-number">06</span>
          </div>
        </div>
        <div class="card-body">
          <h3 style="view-transition-name: card-title-6;">Magnetic Interactions</h3>
          <p>Elements that attract, repel, and respond to cursor proximity with spring physics.</p>
        </div>
      </article>
    </div>
  </div>

  <!-- Detail View (hidden, populated by JS) -->
  <div id="detail-view" class="view">
    <div class="detail-layout">
      <div class="detail-image-area">
        <div id="detail-image" class="detail-image">
          <span id="detail-number" class="detail-number"></span>
        </div>
      </div>
      <div class="detail-content">
        <button id="back-btn" class="back-btn">&larr; Back to grid</button>
        <h2 id="detail-title" class="detail-title"></h2>
        <p id="detail-desc" class="detail-desc"></p>
        <div class="detail-meta">
          <span class="meta-tag">View Transitions API</span>
          <span class="meta-tag">CSS</span>
          <span class="meta-tag">Shared Elements</span>
        </div>
        <p class="detail-body">This demo uses the View Transitions API to animate between a card grid and a detail page. The card image and title have matching <code>view-transition-name</code> properties, allowing the browser to smoothly interpolate their position and size during the transition.</p>
        <p class="detail-body">In browsers that don't support View Transitions, the content swaps instantly with a simple CSS crossfade fallback.</p>
      </div>
    </div>
  </div>

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