<body style="position: relative;">
    <div style="width: 90px; height: 90px; position: absolute; top: 0; left: 0; transform: matrix(.7071, .7071, -.7071, .7071, 0, 0) rotate(-45deg); border: 5px solid green;"></div>
    <div style="width: 90px; height: 90px; position: absolute; top: 5px; left: 5px; background-color: green;"></div>
</body>