css/css-flexbox/flexbox-items-as-stacking-contexts-001.xhtml

<?xml version="1.0" encoding="UTF-8"?>
<!--
     Any copyright is dedicated to the Public Domain.
     http://creativecommons.org/publicdomain/zero/1.0/
-->
<!-- Testcase with flex items containing overlapping content, with
     "z-index" set on some of them, which should make them create
     stacking contexts. -->
<html xmlns="http://www.w3.org/1999/xhtml">
  <head>
    <title>CSS Test: Testing that 'z-index' property makes flex items form stacking contexts</title>
    <link rel="author" title="Daniel Holbert" href="mailto:dholbert@mozilla.com"/>
    <link rel="help" href="http://www.w3.org/TR/css-flexbox-1/#painting"/>
    <link rel="match" href="flexbox-items-as-stacking-contexts-001-ref.xhtml"/>
    <style>
      .flexbox {
        width: 90px;
        height: 10px;
        border: 2px solid gray;
        display: flex;
        margin-bottom: 10px;
      }
      .a {
        width: 10px;
        height: 10px;
        background: lightblue;
        min-width: 0;
      }
      .b {
        width: 10px;
        height: 10px;
        background: pink;
        min-width: 0;
        margin-right: 10px;
      }
      .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  { 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>