<!DOCTYPE html> <html> <head> <!-- Without floats, no clearance applies, thus margin-top of #clear should collapse with margin-bottom of its parent element. --> <style type="text/css"> .separator { height: 20px; margin-bottom: 30px; background-color: green; } </style> </head> <body> <div class="separator"></div> <div class="separator"></div> </body> </html>