<!DOCTYPE html>
<html>
<head>
<style>
.container {
margin-left: 100px;
margin-top: 100px;
}
.child {
position: relative;
width: 100px;
height: 100px;
background-color: black;
</style>
</head>
<body>
<div class="container">
<div class="child"></div>
</div>
</body>
</html>