<div class="btn-pp-surface">
  <div class="btn-pp-area">
    <button class="btn-pp" aria-label="Play">
      <span class="btn-pp-ring" aria-hidden="true"></span>
      <span class="btn-pp-play" aria-hidden="true">▶</span>
      <span class="btn-pp-pause" aria-hidden="true"><span></span><span></span></span>
    </button>
    <div class="btn-pp-info">
      <div class="btn-pp-meta">
        <span class="btn-pp-title">Midnight Drive</span>
        <span class="btn-pp-sub">3:42 · Synthwave</span>
      </div>
      <span class="btn-pp-wave" aria-hidden="true"></span>
    </div>
  </div>
</div>

.btn-pp-surface {
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 28px 36px;
  background: #f2efe9;
  border-radius: 16px;
}
.btn-pp-area { display: flex; align-items: center; gap: 16px; }
.btn-pp-info { display: flex; flex-direction: column; gap: 6px; }
.btn-pp-meta { display: flex; flex-direction: column; gap: 2px; }
.btn-pp-title {
  font-family: ui-sans-serif, system-ui, sans-serif;
  font-size: 13px;
  font-weight: 600;
  color: #1a1814;
}
.btn-pp-sub {
  font-family: ui-monospace, "SF Mono", Menlo, monospace;
  font-size: 9px;
  letter-spacing: 1px;
  color: #b0aaa0;
}
.btn-pp {
  position: relative;
  width: 64px;
  height: 64px;
  flex-shrink: 0;
  border: none;
  border-radius: 50%;
  background: #1a1814;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: transform 0.2s cubic-bezier(.34,1.56,.64,1), background 0.3s;
}
.btn-pp:hover { transform: scale(1.1); background: #333; }
.btn-pp:active { transform: scale(0.93); }
.btn-pp-play {
  position: relative;
  z-index: 1;
  margin-left: 3px;
  font-size: 24px;
  line-height: 1;
  color: #fff;
  transition: opacity 0.15s, transform 0.15s;
}
.btn-pp-pause {
  position: absolute;
  z-index: 1;
  display: flex;
  gap: 5px;
  opacity: 0;
  transform: scale(0.5);
  transition: opacity 0.2s, transform 0.2s;
}
.btn-pp-pause span { width: 4px; height: 20px; border-radius: 2px; background: #fff; }
.btn-pp.is-playing .btn-pp-play { opacity: 0; transform: scale(0); }
.btn-pp.is-playing .btn-pp-pause { opacity: 1; transform: scale(1); }
.btn-pp-ring {
  position: absolute;
  inset: -6px;
  border-radius: 50%;
  border: 2px solid rgba(26,24,20,0.2);
}
.btn-pp.is-playing .btn-pp-ring { animation: btn-pp-ring 2s ease-in-out infinite; }
@keyframes btn-pp-ring {
  0%,100% { transform: scale(1); opacity: 0.5; }
  50%     { transform: scale(1.15); opacity: 0.15; }
}
.btn-pp-wave {
  display: flex;
  align-items: center;
  gap: 4px;
  height: 36px;
}
.btn-pp-bar {
  width: 3px;
  border-radius: 2px;
  background: #1a1814;
  opacity: 0.25;
  transition: height 0.3s, opacity 0.3s;
}
.btn-pp-bar.is-active {
  opacity: 0.7;
  animation: btn-pp-dance var(--dur, 0.8s) ease-in-out infinite alternate;
}
@keyframes btn-pp-dance {
  from { height: var(--min, 4px); }
  to   { height: var(--max, 28px); }
}
@media (prefers-reduced-motion: reduce) {
  .btn-pp.is-playing .btn-pp-ring,
  .btn-pp-bar.is-active { animation: none; }
}

document.querySelectorAll('.btn-pp-area').forEach(function (area) {
  var btn = area.querySelector('.btn-pp');
  var wave = area.querySelector('.btn-pp-wave');
  var playing = false;
  var barCount = 18;
  var heights = [];
  for (var i = 0; i < barCount; i++) {
    var mid = barCount / 2;
    var d = Math.abs(i - mid) / mid;
    var h = { min: 3 + d * 3, max: 6 + (1 - d * d) * 26 };
    heights.push(h);
    var bar = document.createElement('span');
    bar.className = 'btn-pp-bar';
    bar.style.height = h.min + 'px';
    bar.style.setProperty('--min', h.min + 'px');
    bar.style.setProperty('--max', h.max + 'px');
    bar.style.setProperty('--dur', (0.4 + Math.random() * 0.7).toFixed(2) + 's');
    bar.style.animationDelay = (Math.random() * 0.5).toFixed(2) + 's';
    wave.appendChild(bar);
  }
  btn.addEventListener('click', function () {
    playing = !playing;
    btn.classList.toggle('is-playing', playing);
    btn.setAttribute('aria-label', playing ? 'Pause' : 'Play');
    var bars = wave.querySelectorAll('.btn-pp-bar');
    bars.forEach(function (b, i) {
      if (playing) {
        b.classList.add('is-active');
        b.style.height = '';
      } else {
        b.classList.remove('is-active');
        b.style.height = heights[i].min + 'px';
      }
    });
  });
});