CSS Animatable left Property Example

<!DOCTYPE html>
<html>
<head>
<style> 
#container1, #container2 {
  	display: flex;
  	justify-content: center;
    align-items: center;
    color: #fff;
    font-size: 20px;
    font-weight: bold;
	width: 120px;
	height: 100px;
	position: absolute;
    box-shadow: 0 0 10px 0 #aaa;
}
#container1 {
    background: #f00;
    left: 0;
	animation: anim1 5s infinite;
}
#container2 {
    background: #00f;
    bottom: 0;
    left: calc(100% - 120px);
	animation: anim2 5s infinite;
}

@keyframes anim1 {
	50% {left: calc(100% - 120px);}
}
@keyframes anim2 {
	50% {left: 0;}
}
</style>
</head>
<body>

<h1>Animatable 'left' Property</h1>
<hr>

<p>Experience the changing position of the container using left property.<p>
<div id="container1">Container 1</div>
<div id="container2">Container 2</div>

</body>
</html>