<!DOCTYPE html> <html> <head> <style type="text/css"> #separator-top { height: 20px; margin-bottom: 20px; background-color: green; } #overflow { background-color: green; height: 40px; } #separator-bottom { height: 20px; margin-top: 20px; background-color: green; } </style> </head> <body> <div id="separator-top"></div> <div id="overflow"></div> <div id="separator-bottom"></div> </body> </html>