<!DOCTYPE html> <html> <head> <style type="text/css"> #block1 { height: 20px; margin-bottom: 80px; background-color: green; } #margin-only { margin-top: -40px; margin-bottom: 20px; } #block2 { height: 20px; margin-top: -10px; background-color: green; } </style> </head> <body> <div id="block1"></div> <div id="margin-only"></div> <div id="block2"></div> </body> </html>
