<!DOCTYPE html> <html> <head> <style type="text/css"> #a { height: 20px; background-color: green; } #b { background-color: green; margin-top: 10px; } #c { margin-top: 20px; margin-bottom: 30px; height: 0; } #d { height: 10px; background-color: red; } </style> </head> <body> <div id="a"></div> <div id="b"> <div id="c"> <div id="d"></div> </div> </div> </body> </html>
