css/motion/offset-path-ray-018-ref.html

<!doctype html>
<meta charset="utf-8">
<title>CSS Motion Path test reference: ray() path with content-box</title>

<style>
  #outer {
    top: 100px;
    left: 100px;
    position: relative;
    width: 200px;
    height: 200px;
    padding: 50px;
    border: 50px solid black;
  }
  #box {
    background-color: green;
    transform: translate(100px, 0px);
    width: 100px;
    height: 100px;
  }
</style>

<div id="outer">
  <div id="box"></div>
</div>