<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html40/strict.dtd"> <!-- vim:sw=4:et:ts=4 --> <html lang="en-US"> <head> <title>z-index testcase: 'auto' doesn't establish new stacking context (position: relative)</title> <meta http-equiv="Content-Style-Type" content="text/css"> <link rel="copyright" href="/~dbaron/legal.html"> <style type="text/css"> div { height: 100px; width: 100px; margin: 0; border: none; padding: 0; position: relative; } div#contain { z-index: auto; } div#two { background: green; z-index: 2; } div#one, div#three { background: red; z-index: 1; } div#contain, div#three { margin-top: -100px; } </style> </head> <body> <div id="one"></div> <div id="contain"> <div id="two"></div> <div id="three"></div> </div> </body> </html>