backdrop-filters-grayscale-001.html

<!DOCTYPE html>
<title>CSS Backdrop Filters: Grayscale(50%)</title>
<link rel="author" href="mailto:[email protected]">
<link rel="help" href="https://drafts.fxtf.org/filter-effects-2/#BackdropFilterProperty">
<link rel="help" href="https://drafts.fxtf.org/filter-effects-1/#supported-filter-functions">
<link rel="help" href="https://bugs.chromium.org/p/chromium/issues/detail?id=831485">
<link rel="match" href="reference/backdrop-filters-grayscale-001-ref.html">
<meta name="assert" content="Check that backdrop-filter works with grayscale(50%)."/>
<style>
.square {
    position: absolute;
    width: 100px;
    height: 100px;
    top: 100px;
    left: 100px;
    background: blue;
}

.filt {
    backdrop-filter: grayscale(50%);
    position: absolute;
    width: 200px;
    height: 200px;
    top: 50px;
    left: 50px;
}

.greenbox {
    position: absolute;
    width: 50px;
    height: 50px;
    top: 75px;
    left: 75px;
    background: green;
}
</style>
<p>You should see a dark blue rectangle with a green box.</p>
<div class="square"></div>
<div class="filt">
    <div class="greenbox"></div>
</div>

chromium/third_party/blink/web_tests/external/wpt/css/filter-effects/backdrop-filters-grayscale-001.html