<!DOCTYPE html>
<html>
<head>
<title>Title of the document</title>
<style>
.largerBox {
width: 250px;
height: 250px;
background-color: #c3c9c5;
position: relative;
}
.parent {
width: 170px;
height: 170px;
background-color: #7a7a7a;
position: absolute;
bottom: 0px;
}
.child {
width: 90px;
height: 90px;
background-color: #fff;
position: absolute;
right: 0px;
top: 0px;
}
</style>
</head>
<body>
<div class="largerBox">
<div class="parent">
<div class="child"></div>
</div>
</div>
</body>
</html>