<!DOCTYPE html>
<style>
body {
margin: 0;
}
</style>
<div style="width: 100px; height: 100px; background-color: green;"></div>
<!DOCTYPE html>
<style>
body {
margin: 0;
}
</style>
<div style="width: 100px; height: 100px; background-color: green;"></div>