<?xml version="1.0" encoding="UTF-8"?> <!-- Any copyright is dedicated to the Public Domain. http://creativecommons.org/publicdomain/zero/1.0/ --> <!-- Reference case, with floated elements in place of flex items, and using "position: relative" on those elements, to make z-index work on them outside of a flex container. --> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <title>CSS Reftest Reference</title> <link rel="author" title="Daniel Holbert" href="mailto:dholbert@mozilla.com"/> <style> .flexbox { width: 90px; height: 10px; border: 2px solid gray; margin-bottom: 10px; } .a { width: 10px; height: 10px; background: lightblue; min-width: 0; float: left; } .b { width: 10px; height: 10px; background: pink; min-width: 0; margin-right: 10px; float: left; } .aKid { margin-left: 3px; margin-top: 3px; width: 10px; height: 10px; background: steelblue; border: 1px solid blue; } .bKid { margin-left: 3px; margin-top: 6px; width: 10px; height: 10px; background: violet; border: 1px solid purple; } .z0, .z1, .zn1 { position: relative; } .z0 { z-index: 0; } .z1 { z-index: 1; } .zn1 { z-index: -1; } </style> </head> <body> <!-- No "z-index" --> <div class="flexbox"> <div class="a"><div class="aKid"/></div> <div class="b"><div class="bKid"/></div> </div> <!-- Various "z-index" just on the first item --> <div class="flexbox"> <div class="a zn1"><div class="aKid"/></div> <div class="b"><div class="bKid"/></div> <div class="a z0"><div class="aKid"/></div> <div class="b"><div class="bKid"/></div> <div class="a z1"><div class="aKid"/></div> <div class="b"><div class="bKid"/></div> </div> <!-- Various "z-index" just on the second item --> <div class="flexbox"> <div class="a"><div class="aKid"/></div> <div class="b zn1"><div class="bKid"/></div> <div class="a"><div class="aKid"/></div> <div class="b z0"><div class="bKid"/></div> <div class="a"><div class="aKid"/></div> <div class="b z1"><div class="bKid"/></div> </div> <!-- Various "z-index" on the first item, w/ "z-index:0" on second item --> <div class="flexbox"> <div class="a zn1"><div class="aKid"/></div> <div class="b z0"><div class="bKid"/></div> <div class="a z0"><div class="aKid"/></div> <div class="b z0"><div class="bKid"/></div> <div class="a z1"><div class="aKid"/></div> <div class="b z0"><div class="bKid"/></div> </div> <!-- Various "z-index" on the second item, w/ "z-index:0" on first item --> <div class="flexbox"> <div class="a z0"><div class="aKid"/></div> <div class="b zn1"><div class="bKid"/></div> <div class="a z0"><div class="aKid"/></div> <div class="b z0"><div class="bKid"/></div> <div class="a z0"><div class="aKid"/></div> <div class="b z1"><div class="bKid"/></div> </div> </body> </html>