W3Schools Tryit Editor

<!DOCTYPE html>
<html>
<head>
<style>
  #frameDiv {
    width: 200px;
    height: 200px;
    margin: 20px;
    position: relative;
    border: solid black 1px;
    background-color: rgb(205, 242, 205);
  }

span {
    position: absolute;
    top: 0;
    left: 0;
  }

#frameDiv > div {
    width: 50px;
    height: 20px;
    border-radius: 3px 10px 10px 3px;
    background-color: hotpink;
    offset-path: path('M20,170 L100,20 L180,100 Z');
    animation: moveDiv 3s 3;
  }

@keyframes moveDiv {
    100%  { offset-distance: 100%; }
  }
</style>
</head>
<body>

<h1>Animation along an offset-path</h1>

<p>The pink div is animated to follow a path written in SVG syntax.</p>
<p><code>offset-path: path('M20,170 L100,20 L180,100 Z');</code> creates a path that starts in position x,y=20,170 then creates a line to position 100,20 and then a line to 180,100 and then a line back to start.</p>
<ul>
  <li>'M' = moveto</li>
  <li>'L' = lineto</li>
  <li>'Z' = closepath</li>
</ul>
<p>For more info on how to draw an SVG path visit <a href="https://www.w3schools.com/graphics/svg_path.asp" target="_blank">SVG Tutorial -> SVG Path</a></p>

</body>
</html>