<!DOCTYPE html>
<html>
<head>
<style type="text/css">
html, body {
margin: 0; padding: 0;
}
html {
background-color: white;
margin: 20px 0;
body {
background-color: green;
margin: 10px 0;
height: 100px;
</style>
</head>
<body>
</body>
</html>