Reduced Motion Demo

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

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  background: #0d1117;
  color: #e6edf3;
  min-height: 100vh;
  padding: 32px 16px;
  display: flex;
  justify-content: center;
}

.demo {
  width: 100%;
  max-width: 720px;
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.rm-toolbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  background: #161b22;
  border: 1px solid #21262d;
  border-radius: 10px;
  padding: 12px 18px;
  gap: 12px;
  flex-wrap: wrap;
}

.rm-sys-status {
  font-size: 13px;
  color: #8b949e;
}
.rm-sys-status.active {
  color: #f85149;
}
.rm-sys-status.inactive {
  color: #3fb950;
}

.rm-override {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 13px;
  color: #8b949e;
  cursor: pointer;
}
.rm-override input:focus-visible + .rm-override-label {
  outline: 2px solid #6366f1;
  border-radius: 4px;
}
.rm-override-label {
  font-weight: 600;
}

.rm-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 14px;
}

.rm-card {
  background: #161b22;
  border: 1px solid #21262d;
  border-radius: 12px;
  padding: 20px;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 12px;
  min-height: 160px;
  justify-content: center;
}
.rm-card--wide {
  grid-column: 1 / -1;
  flex-direction: row;
  flex-wrap: wrap;
  justify-content: flex-start;
  gap: 14px;
}

.rm-label {
  font-size: 11px;
  font-weight: 700;
  color: #4a555f;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  align-self: flex-start;
  width: 100%;
}

.rm-caption {
  font-size: 11px;
  color: #4a555f;
}

.rm-replay-btn {
  background: #21262d;
  border: 1px solid #30363d;
  color: #8b949e;
  font-size: 12px;
  padding: 5px 12px;
  border-radius: 7px;
  cursor: pointer;
  align-self: flex-start;
}
.rm-replay-btn:hover {
  color: #e6edf3;
  border-color: #8b949e;
}

/* Animations */
.spin-loader {
  width: 36px;
  height: 36px;
  border: 3px solid #30363d;
  border-top-color: #6366f1;
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
}
@keyframes spin {
  to {
    transform: rotate(360deg);
  }
}

.bounce-ball {
  width: 20px;
  height: 20px;
  background: #6366f1;
  border-radius: 50%;
  animation: bounce 0.7s ease-in-out infinite alternate;
}
@keyframes bounce {
  to {
    transform: translateY(-24px);
  }
}

.gradient-shift {
  width: 100%;
  max-width: 120px;
  height: 48px;
  border-radius: 8px;
  background: linear-gradient(270deg, #6366f1, #ec4899, #f59e0b);
  background-size: 300% 100%;
  animation: grad-shift 3s ease infinite;
}
@keyframes grad-shift {
  0%,
  100% {
    background-position: 0% 50%;
  }
  50% {
    background-position: 100% 50%;
  }
}

.slide-demo {
  display: flex;
  flex-direction: column;
  gap: 8px;
  flex: 1;
}
.slide-item {
  background: #21262d;
  border-radius: 7px;
  padding: 8px 14px;
  font-size: 13px;
  color: #cdd6f4;
  opacity: 0;
  transform: translateX(-20px);
  animation: slide-in 0.5s ease forwards;
}
.slide-item:nth-child(1) {
  animation-delay: 0.1s;
}
.slide-item:nth-child(2) {
  animation-delay: 0.3s;
}
.slide-item:nth-child(3) {
  animation-delay: 0.5s;
}
@keyframes slide-in {
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

.parallax-card {
  width: 80px;
  height: 80px;
  border-radius: 12px;
  position: relative;
  background: #0d1117;
  border: 1px solid #30363d;
  overflow: hidden;
  cursor: pointer;
}
.pc-layer {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: transform 0.1s;
}
.pc-layer--back {
  background: radial-gradient(circle at 30% 30%, #1e1e4e, #0d1117);
}
.pc-layer--mid {
  background: transparent;
}
.pc-layer--front {
  font-size: 24px;
  color: #6366f1;
}

/* Fallbacks */
.fallback-dots {
  display: flex;
  gap: 6px;
  align-items: center;
}
.fallback-dots span {
  width: 8px;
  height: 8px;
  background: #6366f1;
  border-radius: 50%;
  animation: pulse-dot 1.2s ease-in-out infinite;
}
.fallback-dots span:nth-child(2) {
  animation-delay: 0.2s;
}
.fallback-dots span:nth-child(3) {
  animation-delay: 0.4s;
}
@keyframes pulse-dot {
  0%,
  100% {
    opacity: 0.4;
  }
  50% {
    opacity: 1;
  }
}

.fallback-static-ball {
  width: 20px;
  height: 20px;
  background: #6366f1;
  border-radius: 50%;
  animation: pulse-opacity 2s ease-in-out infinite;
}
@keyframes pulse-opacity {
  0%,
  100% {
    opacity: 0.5;
  }
  50% {
    opacity: 1;
  }
}

.fallback-static-grad {
  width: 100%;
  max-width: 120px;
  height: 48px;
  border-radius: 8px;
  background: linear-gradient(135deg, #6366f1, #ec4899);
}

.fallback-fade-demo {
  display: flex;
  flex-direction: column;
  gap: 8px;
  flex: 1;
}
.fade-item {
  background: #21262d;
  border-radius: 7px;
  padding: 8px 14px;
  font-size: 13px;
  color: #cdd6f4;
  opacity: 0;
  animation: fade-in 0.4s ease forwards;
}
.fade-item:nth-child(1) {
  animation-delay: 0.1s;
}
.fade-item:nth-child(2) {
  animation-delay: 0.25s;
}
.fade-item:nth-child(3) {
  animation-delay: 0.4s;
}
@keyframes fade-in {
  to {
    opacity: 1;
  }
}

.fallback-static-card {
  width: 80px;
  height: 80px;
  border-radius: 12px;
  background: radial-gradient(circle at 30% 30%, #1e1e4e, #0d1117);
  border: 1px solid #30363d;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 24px;
}

/* Global reduced motion overrides */
@media (prefers-reduced-motion: reduce) {
  .rm-anim {
    display: none !important;
  }
  .rm-fallback {
    display: flex !important;
  }
}

[data-reduced="true"] .rm-anim {
  display: none !important;
}
[data-reduced="true"] .rm-fallback {
  display: flex !important;
}

const mq = window.matchMedia("(prefers-reduced-motion: reduce)");
const statusEl = document.getElementById("rmSysStatus");
const override = document.getElementById("rmOverride");

function updateStatus(reduced) {
  if (reduced) {
    statusEl.textContent = "System preference: Reduced motion ON";
    statusEl.className = "rm-sys-status active";
  } else {
    statusEl.textContent = "System preference: Reduced motion OFF";
    statusEl.className = "rm-sys-status inactive";
  }
}

function applyMotion(reduced) {
  document.body.dataset.reduced = String(reduced);
}

mq.addEventListener("change", (e) => {
  updateStatus(e.matches);
  if (!override.checked) applyMotion(e.matches);
});

updateStatus(mq.matches);
applyMotion(mq.matches);

override.addEventListener("change", () => {
  applyMotion(override.checked || mq.matches);
});

// Parallax on hover
const card = document.getElementById("parallaxCard");
if (card) {
  card.addEventListener("mousemove", (e) => {
    if (document.body.dataset.reduced === "true") return;
    const rect = card.getBoundingClientRect();
    const cx = (e.clientX - rect.left) / rect.width - 0.5;
    const cy = (e.clientY - rect.top) / rect.height - 0.5;
    card.querySelector(".pc-layer--mid").style.transform = `translate(${cx * 6}px, ${cy * 6}px)`;
    card.querySelector(".pc-layer--front").style.transform =
      `translate(${cx * 12}px, ${cy * 12}px)`;
  });
  card.addEventListener("mouseleave", () => {
    card.querySelectorAll(".pc-layer").forEach((l) => (l.style.transform = ""));
  });
}

// Replay slide/fade animation
document.getElementById("replayBtn").addEventListener("click", () => {
  const reduced = document.body.dataset.reduced === "true";
  const slide = document.getElementById("slideDemo");
  const fade = document.getElementById("fadeFallback");

  if (reduced) {
    fade.querySelectorAll(".fade-item").forEach((el) => {
      el.style.animation = "none";
      requestAnimationFrame(() => {
        el.style.animation = "";
      });
    });
  } else {
    slide.querySelectorAll(".slide-item").forEach((el) => {
      el.style.animation = "none";
      requestAnimationFrame(() => {
        el.style.animation = "";
      });
    });
  }
});

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8" />
  <meta name="viewport" content="width=device-width, initial-scale=1.0" />
  <title>Reduced Motion Demo</title>
  <link rel="stylesheet" href="style.css" />
</head>
<body>
<div class="demo">
  <div class="rm-toolbar">
    <span class="rm-sys-status" id="rmSysStatus">System preference: detecting…</span>
    <label class="rm-override">
      <input type="checkbox" id="rmOverride" />
      <span class="rm-override-label">Force reduced motion</span>
    </label>
  </div>

  <div class="rm-grid">

    <div class="rm-card">
      <div class="rm-label">Spin Loader</div>
      <div class="rm-anim spin-loader"></div>
      <div class="rm-fallback fallback-dots" hidden>
        <span></span><span></span><span></span>
      </div>
      <div class="rm-caption">Spinner → Pulsing dots</div>
    </div>

    <div class="rm-card">
      <div class="rm-label">Bounce Ball</div>
      <div class="rm-anim bounce-ball"></div>
      <div class="rm-fallback fallback-static-ball" hidden></div>
      <div class="rm-caption">Bounce → Fade</div>
    </div>

    <div class="rm-card rm-card--wide">
      <div class="rm-label">Slide-in Content</div>
      <div class="rm-anim slide-demo" id="slideDemo">
        <div class="slide-item">Item slides in from left</div>
        <div class="slide-item">Staggered appearance</div>
        <div class="slide-item">Smooth enter animation</div>
      </div>
      <div class="rm-fallback fallback-fade-demo" id="fadeFallback" hidden>
        <div class="fade-item">Item appears with fade</div>
        <div class="fade-item">Simple opacity change</div>
        <div class="fade-item">Respects user preference</div>
      </div>
      <button class="rm-replay-btn" id="replayBtn">↺ Replay</button>
      <div class="rm-caption">Slide → Fade</div>
    </div>

    <div class="rm-card">
      <div class="rm-label">Parallax Card</div>
      <div class="rm-anim parallax-card" id="parallaxCard">
        <div class="pc-layer pc-layer--back"></div>
        <div class="pc-layer pc-layer--mid"></div>
        <div class="pc-layer pc-layer--front">✦</div>
      </div>
      <div class="rm-fallback fallback-static-card" hidden>
        <div class="fsc-content">✦</div>
      </div>
      <div class="rm-caption">Parallax → Static</div>
    </div>

    <div class="rm-card">
      <div class="rm-label">Gradient Shift</div>
      <div class="rm-anim gradient-shift"></div>
      <div class="rm-fallback fallback-static-grad" hidden></div>
      <div class="rm-caption">Animated → Static gradient</div>
    </div>

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