<!DOCTYPE HTML>
<!--
     Any copyright is dedicated to the Public Domain.
     http://creativecommons.org/publicdomain/zero/1.0/
-->
<html><head>
  <meta charset="utf-8">
  <title>Reference: Fragmentation with forced break propagation</title>
  <link rel="author" title="Mats Palmgren" href="https://bugzilla.mozilla.org/show_bug.cgi?id=1144096">
  <style type="text/css">
html,body {
    color:black; background-color:white; font-size:16px; padding:0; margin:0;
}
body { overflow:hidden; }

.columns {
  position:relative;
     -moz-columns: 5;
      -ms-columns: 5;
  -webkit-columns: 5;
          columns: 5;
     -moz-column-fill: auto;
      -ms-column-fill: auto;
  -webkit-column-fill: auto;
          column-fill: auto;
  border: 2px dashed;
  margin-bottom: 5px;
}
.no-border { border-style:none; }

.grid {
  display: grid;
  grid-template-columns: 30px;
  grid-auto-rows: 10px;
  grid-gap: 2px;
  border:5px solid;
  height: 20px; /* create Class C break opportunities at both ends */
  align-content: center;
}
.start {
  align-content: start;
}

span { background:lime; border:1px solid black; }
.bb { border-bottom-width:6px; }
x { display:block; height: 40px; }
.t { border-bottom-width:0; }
.b { border-top-width:0; }
.m {  border:5px solid; border-top-width:0; border-bottom-width:0; }
.br1 { height:34px; border-width:5px; border-top-style:solid; }
.br2 { height:4px; }
.br3 { height:39px; }

</style>
</head>
<body>

<div class="columns" style="height:40px">
<div style="background:grey">
<div class="grid">
<span class="break-before"></span>
</div></div></div>

<div class="columns" style="height:40px">
<div style="background:grey">
<div class="grid start">
<span class="break-before"></span>
</div></div></div>

<div class="columns" style="height:40px">
<div style="background:grey">
<div class="br1"></div>
<div class="grid b">
<span class="avoid-break"><x></x></span>
</div></div></div>

<div class="columns" style="height:40px">
<div style="background:grey">
<div class="grid start">
<span class="avoid-break"><x></x></span>
</div></div></div>

<div class="columns" style="height:40px">
<div style="padding-top:1px; background:grey">
<div class="br3"></div>
<div class="grid">
<span class="break-before"></span>
</div></div></div>

<div class="columns" style="height:40px">
<div style="padding-top:1px; background:grey">
<div class="br3"></div>
<div class="grid start">
<span class="break-before"></span>
</div></div></div>

<div class="columns" style="height:40px">
<div style="padding-top:1px; background:grey">
<div class="br1"></div>
<div class="grid b">
<span class="avoid-break"><x></x></span>
</div></div></div>

<div class="columns" style="height:40px">
<div style="padding-top:1px; background:grey">
<div class="grid start">
<span class="avoid-break"><x></x></span>
</div></div></div>

<div class="columns" style="height:16px">
<div style="background:grey">
<div class="grid" style="height:10px">
<span class="break-before"></span>
</div></div></div>

<div class="columns" style="height:16px">
<div style="padding-top:1px; background:grey">
<div class="br2"></div>
<div class="grid" style="height:10px">
<span class="break-before"></span>
</div></div></div>

<div class="columns" style="height:10px">
<div style="background:grey">
<div class="grid" style="height:10px">
<span class="break-before"></span>
</div></div></div>

<div class="columns" style="height:10px">
<div style="padding-top:1px; background:grey">
<div class="br2"></div>
<div class="grid" style="height:10px">
<span class="break-before"></span>
</div></div></div>

<div class="columns" style="height:0px">
<div style="background:grey">
<div class="grid" style="height:10px">
<span class="break-before"></span>
</div></div></div>

<div class="columns" style="height:0px; margin-top:20px">
<div style="background:grey">
<div style="height:1px; overflow:hidden"></div>
<div class="grid" style="height:10px">
<span class="break-before"></span>
</div></div></div>

<div class="columns no-border" style="height:0px; margin-top:20px">
<div style="height:1px; overflow:hidden"></div>
<div style="height:5px; overflow:hidden; background:black; "></div>
<div class="grid m" style="height:10px;grid-auto-rows: 0px; align-content:start;">
<span class="bb"></span>
</div></div>

<div class="columns no-border" style="height:0px; margin-top:20px">
<div style="">
<div style="height:1px; overflow:hidden"></div>
<div style="height:5px; overflow:hidden; background:black; "></div>
</div>
<div style="height:7px; width:30px; margin-left:5px; overflow:hidden; background:black;"></div>
<div class="grid m" style="height:10px;grid-auto-rows: 0px; align-content:start;">
<span class="bb"></span>
</div></div>

<div class="columns no-border" style="height:0px; margin-top:20px">
<div style="height:1px; overflow:hidden; position:relative"></div>
<div style="border:5px solid; height:1px; overflow:hidden; ">
<div style="height:7px; width:30px; overflow:hidden;  position:absolute; background:black;"></div>
</div>
</div>
</div>

<div class="columns no-border" style="height:0px; margin-top:20px">
<div style="padding-top:1px; ">
<div style="height:1px; overflow:hidden"></div>
<div class="grid" style="height:1px;grid-auto-rows: 1px;">
<span class="break-before bb"></span>
<span class="break-before bb"></span>
</div></div></div>

<div class="columns no-border" style="height:0px; margin-top:20px">
<div style="padding-top:1px; ">
<div style="height:1px; overflow:hidden"></div>
<div class="grid" style="height:1px;grid-auto-rows: 11px;">
<span class="break-before bb"></span>
<span class="break-before bb"></span>
</div></div></div>

<div class="columns no-border" style="height:0px; margin-top:20px">
<div style="padding-top:1px; ">
<div style="height:1px; overflow:hidden"></div>
<div class="grid" style="height:1px;grid-auto-rows: 11px;">
<span class="break-before bb" style="grid-row:span 2"></span>
<span class="break-before bb"></span>
</div></div></div>


<div class="columns no-border" style="height:0px; margin-top:20px">
<div style="padding-top:1px; ">
<div style="height:1px; overflow:hidden"></div>
<div class="grid" style="height:1px;grid-auto-rows: 11px;">
<span class="break-before bb"></span>
<span class="break-before bb" style="grid-row:span 2"></span>
</div></div></div>

</body>
</html>