<!DOCTYPE HTML>
<html>
<head>
<style>
    .wackeddiv {
        position: fixed;
        left: 20px;
        top: 20px;
        width: 50px;
        height: 50px;
        border: 2px solid highlight;
        background-color: transparent;
        -moz-transform: rotate(90deg); 
    }
    
    .posabssemitransparentblack {
        position:absolute;
        left: 0px;
        top: 50px;
        width: 100px;
        height: 100px;
        background: lime;
        opacity: 0.1;
    }
</style>
</head>
<body>
    <div class="posabssemitransparentblack"></div>
    <div class="wackeddiv"></div>
</body>
</html>