<!DOCTYPE html>
<html>
  <head>
    <title>CSS Motion Path: ray paths with contain</title>
    <style>
      #container {
        width: 250px;
        height: 250px;
        transform: translate(100px);
      }
      #target {
        position: relative;
        left: 50px;
        top: 50px;
        width: 150px;
        height: 25px;
        background-color: lime;
        /*
         * The original path length is 50px, contain applies
         * decrease, so that the new length is -25px (-150px / 2).
         * Note: offset-anchor is "200% -300%", and ray angle is -90deg
           and offset-rotate is -90deg.
         */
        transform: translate(-75px, -12.5px) rotate(-90deg) translate(-225px, 87.5px);
      }
    </style>
  </head>
  <body>
    <div id="container">
      <div id="target"></div>
    </div>
  </body>
</html>
