<!DOCTYPE html>
<html>
<head>
<title>CSS Motion Path: ray paths with contain</title>
<style>
#container {
width: 300px;
height: 300px;
}
#target {
position: relative;
left: 30px;
top: 40px;
width: 10px;
height: 10px;
background-color: lime;
/* ray length is sqrt(30^2 + 40^2); contain does -max(10, 10) / 2; */
/* the result length is 45px. angle is 180deg; */
/* 5 is origin shift. */
transform: translate(-5px, 40px);
}
</style>
</head>
<body>
<div id="container">
<div id="target"></div>
</div>
</body>
</html>