data/train/codepen-AKOQrA-wBKmbm/full.html

<!DOCTYPE html>
<html>
<head>
  <style>.loading {
  position: absolute;
  top: 50%;
  left: 50%;
}
.loading-bar {
  display: inline-block;
  width: 4px;
  height: 18px;
  border-radius: 4px;
  animation: loading 1s ease-in-out infinite;
}
.loading-bar:nth-child(1) {
  background-color: #3498db;
  animation-delay: 0;
}
.loading-bar:nth-child(2) {
  background-color: #c0392b;
  animation-delay: 0.09s;
}
.loading-bar:nth-child(3) {
  background-color: #f1c40f;
  animation-delay: .18s;
}
.loading-bar:nth-child(4) {
  background-color: #27ae60;
  animation-delay: .27s;
}

@keyframes loading {
  0% {
    transform: scale(1);
  }
  20% {
    transform: scale(1, 2.2);
  }
  40% {
    transform: scale(1);
  }
}</style>
</head>
<body>
  <div class="loading">
  <div class="loading-bar"></div>
  <div class="loading-bar"></div>
  <div class="loading-bar"></div>
  <div class="loading-bar"></div>
</div>
  <script></script>
</body>
</html>