<!DOCTYPE html>
<html><head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8"><title>CSS Test Reference</title>
<meta charset="utf-8">
<link rel="author" title="Emilio Cobos Álvarez" href="mailto:emilio@crisal.io">
<style>
.parent {
position: fixed;
top: 0;
left: 0;
display: block;
width: 200px;
height: 200px;
background: yellow;
}
.child {
position: absolute;
left: 50px;
top: 50px;
width: 100px;
height: 100px;
background: green;
}
</style>
</head><body><div class="parent"><div class="child"></div></div>
</body></html>