<!DOCTYPE html> <html> <head> <title>Bug 1122366 - margin collapsing</title> <style type="text/css"> div { font: 40px/1em serif; height: 4em; } div.wrapper { margin: 10px; background: blue; border-left: green solid .5em; border-right: green solid 1.5em; width: 2em; } </style> </head> <body> <div class="wrapper"> </div> <div class="wrapper"> </div> </body> </html>