<!DOCTYPE html>
<style>
body, html {
width: 100%;
height: 100%;
margin: 0;
background-color: green;
border: 5px solid black;
box-sizing: border-box;
}
</style>
<!DOCTYPE html>
<style>
body, html {
width: 100%;
height: 100%;
margin: 0;
background-color: green;
border: 5px solid black;
box-sizing: border-box;
}
</style>