<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"> <html lang="en" xmlns="http://www.w3.org/1999/xhtml"> <head> <title>CSS Test: Margin Collapsing: top margins</title> <link rel="author" title="Ian Hickson" href="mailto:ian@hixie.ch"/> <link rel="alternate" href="http://www.hixie.ch/tests/adhoc/css/box/block/margin-collapse/040.html" type="text/html"/> <link rel="help" href="http://www.w3.org/TR/CSS21/box.html#collapsing-margins"/> <style type="text/css"> .a { margin: 0; background: red; } .b { margin: 2em 0 0 0; background: red; } .c { margin: 0; background: red; } .d { margin: 1em 0 0 0; background: green; color: white; } </style> </head> <body> <p>There should be no red below.</p> <div class="a"> <div class="b"> <div class="c"> <div class="d"> This line should be green. </div> </div> </div> </div> </body> </html>