<!DOCTYPE html>
<html>
<head>
<title>The title of the document</title>
<style>
.element {
width: 200px;
height: 200px;
background: #666;
color: #eee;
backface-visibility: visible;
-webkit-animation: element 2s infinite linear alternate;
animation: element 2s infinite linear alternate;
}
@-webkit-keyframes element {
to {
-webkit-transform: rotateY(180deg);
}
}
</style>
</head>
<body>
<h2>Backface-visibility property example</h2>
<div class="element">
<h2>Hello world!</h2>
</div>
</body>
</html>