<!doctype html>
<meta charset="utf-8">
<title>CSS Test: will-change: backdrop-filter should create a stacking context.</title>
<link rel="author" title="Philip Rogers" href="mailto:pdr@chromium.org">
<link rel="help" href="https://bugs.chromium.org/p/chromium/issues/detail?id=960953">
<link rel="help" href="https://drafts.csswg.org/css-will-change/#will-change">
<link rel="help" href="https://drafts.fxtf.org/filter-effects-2/#BackdropFilterProperty">
<link rel="match" href="green-square-100-by-100-ref.html">
<style>
  html, body { margin: 0; }
  .indicator {
    position: absolute;
    background-color: green;
    z-index: 1;
  }
  .willchange {
    will-change: backdrop-filter;
    z-index: 0;
  }
  .child {
    position: relative;
    background-color: red;
    z-index: 2;
  }
  .box {
    width: 100px;
    height: 100px;
  }
</style>

<div class="indicator box"></div>
<div class="willchange box">
  <!-- Because will-change: backdrop-filter creates a stacking context, this
       child remains on bottom even though it has a higher z-index than the
       indicator box. -->
  <div class="child box"></div>
</div>