<!DOCTYPE html>
<html>
<head>
<title>CSS Motion Path: ray paths with contain</title>
<style>
#container {
width: 300px;
height: 300px;
}
#target {
position: relative;
left: 100px;
top: 100px;
width: 100px;
height: 100px;
background-color: lime;
/* ray length is sqrt(150^2 + 0^2); contain does -max(100, 100) / 2; */
/* the result length is 100. sin(45deg) * length = 70.71; */
transform: rotate(-45deg) translate(100px) rotate(45deg);
}
</style>
</head>
<body>
<div id="container">
<div id="target"></div>
</div>
</body>
</html>