<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0//EN"> <html lang="en"> <head> <title>Margin Collapsing: effect of margins on collapsing-through</title> <style type="text/css"> td { border: solid; background: red; padding: 0; font: 3em/1 Ahem; } .bg { background: orange; color: yellow; } .a { margin: 0 0 1em 0; background: lime; } .c { margin: 1em 0 0 0; background: aqua; } .b1 { margin: 1em 0 1em 0; } .b2 { margin: 0em 0 1em 0; } .b3 { margin: 1em 0 0em 0; } .b4 { margin: 0em 0 0em 0; } .b5 { margin: 0.5em 0 0.5em 0; } .b6 { margin: 0em 0 0.5em 0; } .b7 { margin: 0.5em 0 0em 0; } .control .a { margin: 0 0 1em 0; } .control .c { margin: 0; } </style> </head> <body> <p>All the following should look the same (and all should look like the first).</p> <table> <tr> <td class="control"> <div class="bg"> <div class="a">A</div> <div class="c">C</div> </div> </td> <td> <div class="bg"> <div class="a">A</div> <div class="b1"></div> <div class="c">C</div> </div> </td> <td> <div class="bg"> <div class="a">A</div> <div class="b2"></div> <div class="c">C</div> </div> </td> <td> <div class="bg"> <div class="a">A</div> <div class="b3"></div> <div class="c">C</div> </div> </td> <td> <div class="bg"> <div class="a">A</div> <div class="b4"></div> <div class="c">C</div> </div> </td> <td> <div class="bg"> <div class="a">A</div> <div class="b5"></div> <div class="c">C</div> </div> </td> <td> <div class="bg"> <div class="a">A</div> <div class="b6"></div> <div class="c">C</div> </div> </td> <td> <div class="bg"> <div class="a">A</div> <div class="b7"></div> <div class="c">C</div> </div> </td> </tr> </table> </body> </html>