<!DOCTYPE html>

<html>
<head>
    <style>
        .box {
            position: fixed;
            top: 0;
            left: 0;
            width: 300px;
            height: 300px;
            background-color: blue;
            clip: rect(100px, 400px, 200px, 100px);
        }
        
        .indicator {
            position: fixed;
            top: 50px;
            left: 50px;
            width: 50px;
            height: 50px;
            top: ;
            background-color: green;
        }
    </style>
</head>
<body>
<div class="indicator"></div>
<div class="box">
    &nbsp;
</div>
</body>
</html>