<html>
    <head>
        <style type="text/css">
            .green {
                width: 100px;
                height: 100px;
                background-color: rgba(0, 128, 0, 128);
                opacity: 0.5;
                display: block;
            }
            .blue {
                width: 100px;
                height: 100px;
                background-color: rgba(0, 0, 128, 128);
                opacity: 0.5;
                display: block;
                -webkit-transform: translate(50px, 50px);
            }

            .composited {
                -webkit-transform-style: preserve-3d;
            }
        </style>
    </head>
    <body>
        <div class="green composited">
            <div class="blue composited">
            </div>
        </div>
    </body>
</html>