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

<!DOCTYPE html>
<html>
<head>
  <style>.bar {
  width: 100%;
  height: 20px;
  border: 1px solid #2980b9;
  border-radius: 3px;
  background-image: 
    repeating-linear-gradient(
      -45deg,
      #2980b9,
      #2980b9 11px,
      #eee 10px,
      #eee 20px /* determines size */
    );
  background-size: 28px 28px;
  animation: move .5s linear infinite;
}

@keyframes move {
  0% {
    background-position: 0 0;
  }
  100% {
    background-position: 28px 0;
  }
}</style>
</head>
<body>
  <div class="bar"></div>
  <script></script>
</body>
</html>