<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0//EN"> <html lang="en"> <head> <title>Margin Collapsing: in flow (height)</title> <style type="text/css"> table { border-spacing: 0; font-size: 50px; border: solid; background: red; } td { padding: 0; width: 1em; } /* test */ .test .outer { background: orange; } .test .a { background: red; margin: 0; height: auto; } .test .aa { background: yellow; margin: 0 0 1em 0; height: 1em; } .test .b { background: lime; margin: 0; height: 1em; } /* control */ .control .a { border-top: 1em yellow solid; } .control .b { border-top: 1em orange solid; } .control .c { border-top: 1em lime solid; } </style> </head> <body> <p>The following box should contain exactly three bands, one yellow, one orange, and one lime, with <strong>absolutely no red visible</strong>.</p> <table> <tr> <td class="test"> <div class="outer"> <div class="a"> <div class="aa"></div> </div> <div class="b"></div> </div> </td> <td class="control"> <div class="a"></div> <div class="b"></div> <div class="c"></div> </td> </tr> </table> </body> </html>