css/css-flexbox/percentage-heights-015.html

<!DOCTYPE html>
<html>
  <meta charset="utf-8">
  <title>CSS Flexbox Test: Test the percentage resolution of a child in a flex item that has an indefinite main size</title>
  <link rel="author" title="Daniel Holbert" href="mailto:dholbert@mozilla.com">
  <link rel="author" title="Ting-Yu Lin" href="mailto:tlin@mozilla.com">
  <link rel="author" title="Mozilla" href="https://www.mozilla.org/">
  <link rel="help" href="https://drafts.csswg.org/css-flexbox-1/#definite-sizes">
  <link rel="help" href="https://bugzilla.mozilla.org/show_bug.cgi?id=1654044">
  <link rel="match" href="percentage-heights-015-ref.html">

  <style>
  .container {
    display: inline-flex;
    flex-direction: column;
    width: 100px;
    max-height: 200px;
  }

  .item {
    min-height: 0px;
    background: red;
    width: 100px;
  }

  .child {
    height: 50%;
    background: green
  }

  .tall {
    height: 250px;
  }
  </style>

  <p>You should not see any red (except perhaps as the background of a vertical scrollbar)</p>

  <div class="container">
    <div class="item" style="overflow:hidden">
      <div class="child">
        <div class="tall"></div>
      </div>
    </div>
  </div>

  <div class="container">
    <div class="item" style="overflow:auto">
      <div class="child">
        <div class="tall"></div>
      </div>
    </div>
  </div>

  <div class="container">
    <div class="item" style="overflow:scroll">
      <div class="child">
        <div class="tall"></div>
      </div>
    </div>
  </div>

  <div class="container">
    <div class="item" style="overflow:visible">
      <div class="child" >
        <div class="tall"></div>
      </div>
    </div>
  </div>
</html>