<!DOCTYPE html> <html> <head> <style type="text/css"> html, body { margin: 0; padding: 0; background-color: green; } div { margin: 30px 20px; background-color: red; height: 20px; } div div { margin: 50px; background-color: blue; } </style> </head> <body> <div><div></div></div> </body> </html>
