Свойство transform-style

transform-style: flat | preserve-3d;

<!DOCTYPE html>
<html lang='ru'>
<head>
<meta charset='UTF-8'>
<meta name='viewport' content='width=device-width, initial-scale=1.0'>
<title>Document</title>
</head>
<body>
<div class='example-2'>
 <div class='example-2-front'></div>
 <div class='example-2-back'></div>
 </div>
 
 <style>
 .example-2 {
 width: 200px;
 height: 200px;
 margin: 50px auto;
 transform: rotateX(-30deg) rotateY(-30deg);
 transform-style: preserve-3d;
 }
 .example-2-front,
 .example-2-back {
 width: 200px;
 height: 200px;
 position: absolute;
 }
 .example-2-front {
 background-color: red;
 transform: translateZ(50px);
 }
 .example-2-back {
 background-color: green;
 transform: translateZ(-50px);
 }
 </style>
</body>
</html>