css/css-position/position-sticky-table-th-bottom.html

<!DOCTYPE html>
<title>position:sticky bottom constraint should behave correctly for &lt;th&gt; elements</title>
<link rel="match" href="position-sticky-table-th-bottom-ref.html" />
<link rel="help" href="https://www.w3.org/TR/css-position-3/#sticky-pos" />
<meta name="assert" content="This test checks that the position:sticky bottom constraint behaves correctly for &lt;th&gt; elements" />

<style>
table {
  border-collapse:collapse;
}

td, th {
  padding: 0;
}

td > div, th > div {
  height: 50px;
  width: 50px;
}

.group {
  display: inline-block;
  position: relative;
  width: 150px;
  height: 200px;
}

.scroller {
  position: relative;
  width: 100px;
  height: 150px;
  overflow-x: hidden;
  overflow-y: auto;
}

.prepadding {
  height: 100px;
}

.postpadding {
  height: 250px;
}

.indicator {
  position: absolute;
  background-color: red;
  left: 0;
  height: 50px;
  width: 50px;
}

.sticky {
  position: sticky;
  bottom: 25px;
  background-color: green;
}
</style>

<script>
window.addEventListener('load', function() {
  document.getElementById('scroller1').scrollTop = 0;
  document.getElementById('scroller2').scrollTop = 75;
  document.getElementById('scroller3').scrollTop = 200;
});
</script>

<div class="group">
  <div id="scroller1" class="scroller">
    <div class="indicator" style="top: 100px;"></div>
    <div class="prepadding"></div>
    <table>
      <tbody>
        <tr><td><div></div></td></tr>
        <tr><td><div></div></td></tr>
        <tr><td><div></div></td></tr>
      </tbody>
      <tfoot>
        <tr>
          <th class="sticky"><div></div></th>
        </tr>
      </tfoot>
    </table>
    <div class="postpadding"></div>
  </div>
</div>

<div class="group">
  <div id="scroller2" class="scroller">
    <div class="indicator" style="top: 150px;"></div>
    <div class="prepadding"></div>
    <table>
      <tbody>
        <tr><td><div></div></td></tr>
        <tr><td><div></div></td></tr>
        <tr><td><div></div></td></tr>
      </tbody>
      <tfoot>
        <tr>
          <th class="sticky"><div></div></th>
        </tr>
      </tfoot>
    </table>
    <div class="postpadding"></div>
  </div>
</div>

<div class="group">
  <div id="scroller3" class="scroller">
    <div class="indicator" style="top: 250px;"></div>
    <div class="prepadding"></div>
    <table>
      <tbody>
        <tr><td><div></div></td></tr>
        <tr><td><div></div></td></tr>
        <tr><td><div></div></td></tr>
      </tbody>
      <tfoot>
        <tr>
          <th class="sticky"><div></div></th>
        </tr>
      </tfoot>
    </table>
    <div class="postpadding"></div>
  </div>
</div>

<div>You should see three green boxes above. No red should be visible.</div>