css/css-flexbox/flex-box-wrap.html

<!DOCTYPE html>
<html>
<head>
    <title>CSS Flexbox Test: flex-wrap: wrap</title>
    <link rel="author" title="Tsuyoshi Tokuda" href="mailto:tokuda109@gmail.com">
    <link rel="help" href="http://www.w3.org/TR/css-flexbox-1/#flex-wrap-property">
    <link rel="match" href="reference/flex-box-wrap-ref.html">
    <meta name="assert" content="the test passes if you see green box.">
    <style type="text/css">

       .flex-box {
         position: relative;
         display: flex;
         flex-wrap: wrap;
         margin: 0;
         padding-left: 0;
         width: 200px;
       }
       .flex-item,
       .error {
         list-style-type: none;
         width: 120px;
         height: 100px;
         background-color: green;
       }
       .error {
         position: absolute;
         top: 100px;
         left: 0;
         background-color: red;
         z-index: -1;
       }

    </style>
</head>
<body>
    <p>There should be a green block with no red.</p>

    <ul class="flex-box">
      <li class="flex-item">width: 120px</li>
      <li class="flex-item">width: 120px</li>
      <li class="error"></li>
    </ul>

</body>
</html>