filter-effects-1/#funcdef-filter-invert">
    <link rel="help" href="https://www.w3.org/TR/filter-effects-1/#funcdef-filter-opacity">
    <link rel="help" href="http://www.w3.org/TR/css3-animations/#animations">
    <link rel="match" href="css-filters-animation-combined-001-ref.html">
    <meta name="assert" content="The black square should be a gray square 10px blurred">
    <style type="text/css">
        @keyframes animate {
            0% {
                filter:
                    blur(20px)
        