html/ms-like.html

<!DOCTYPE html>
<html>
<head>
  <style>
    .L {
      position: fixed;
      top: 0;
      left: 0;
      height: 100%;
      width: 100%;
      background: #000;
    }
    .d {
      position: absolute;
      top: calc(50% - 2px);
      left: -4px;
      height: 4px;
      width: 4px;
      background: #fff;
      animation: A 4s cubic-bezier(0, .8, 1, .2) calc(var(--d) * .2s) infinite;
    }
    @keyframes A {
      50%, to {
        transform: translateX(calc(100vw + 4px));
      }
    }
  </style>
</head>
<body>
  <div class="L">
    <div style="--d:1" class="d"></div>
    <div style="--d:2" class="d"></div>
    <div style="--d:3" class="d"></div>
    <div style="--d:4" class="d"></div>
    <div style="--d:5" class="d"></div>
    <div style="--d:6" class="d"></div>
    <div style="--d:7" class="d"></div>
  </div>
</body>
</html>