JSFiddle - React, Tailwind, and code Playground

by otinanaipali

HTML

<div id="main">
    <svg xmlns="http://www.w3.org/2000/svg" version="1.1">
        <defs>
            <filter id="f1" x="0" y="0">
                <feGaussianBlur in="SourceGraphic" stdDeviation="2" />
            </filter>
        </defs>
    </svg>
    <p>Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod
        tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam,
        quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo
        consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse
        cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat
        non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.
        Sed ut perspiciatis unde omnis iste natus error sit voluptatem accusantium
        doloremque laudantium, totam rem aperiam, eaque ipsa quae ab illo inventore
        veritatis et quasi architecto beatae vitae dicta sunt explicabo. Nemo enim
        ipsam voluptatem quia voluptas sit aspernatur aut odit aut fugit, sed quia
        consequuntur magni dolores eos qui ratione voluptatem sequi nesciunt. Neque
        porro quisquam est."</p>
</div>
<div id="blurContainer">
     <h1>Modal</h1>

</div>
<div id="blurry"></div>

CSS

body, html {
    height:100%;
    min-height:100%;
    margin: 0;
    padding: 0;
}
svg {
    height:0;
}
#main {
    background:url('http://lorempixel.com/800/800/nature') no-repeat;
    width:800px;
    height:700px;
}
#blurContainer {
    position:fixed;
    width:300px;
    height:300px;
    top: 50%;
    left: 50%;
    margin:-150px 0 0 -150px;
    border-radius:120px;
    box-shadow:inset 0px 1px 0px 0px #fff, inset 0px -1px 2px 0px #000, 0 5px 8px rgba(0, 0, 0, .8), 0 0px 0px 1px rgba(0, 0, 0, .3);
    background: -moz-linear-gradient(top, rgba(0, 0, 0, 0) 0%, rgba(0, 0, 0, 0.7) 100%);
    z-index:2;
}
#blurry {
    position:fixed;
    z-index:1;
    width:300px;
    height:300px;
    top: 50%;
    left: 50%;
    margin:-150px 0 0 -150px;
    border-radius:120px;
    background:-moz-element(#main) no-repeat fixed;
    /*background-size:118%; /* You may use zoom for extra realism */
    filter:url(#f1);
    color:#fff;
    font-weight:bold;
}
#main p {
    width:400px;
    color:#fff;
    margin:50px auto 0;
}
#blurContainer h1 {
    font:small-caps bold 26px Times New Roman;
    text-transform:capitalize;
    text-align:center;
    color:#0000;
    padding:10px 0 0 0;
    display:block;
    height:50%;
    border-radius:120px 120px 10px 10px;
    text-shadow:0 1px 0px rgba(255, 255, 255, .75);
    background: -moz-linear-gradient(top, rgba(255, 255, 255, 0.6) 0%, rgba(255, 255, 255, 0.1) 100%)
}

JavaScript

$(window).scroll(function () {
    var y = $(this).scrollTop();
    var x = $(this).scrollLeft();
    $('#blurry').css('background-position', parseInt(-x) + 'px ' + parseInt(-y) + 'px');
});