<!DOCTYPE html>

<html>
<head>
    <style>
        .box {
            width: 250px;
            height: 250px;
            margin: 10px;
            background-color: green;
            box-sizing: border-box;
            -webkit-mask-image: linear-gradient(black, transparent);
            border: 5px solid black;
        }

        .composited {
            transform: translateZ(0);
        }
    </style>
</head>
<body>

<p>Both boxes should look the same, and show a fade to the bottom.</p>
<div class="masked composited box"></div>
<div class="masked composited box" style="-webkit-transform-style: preserve-3d;"></div>

</body>
</html>