JSFiddle - React, Tailwind, and code Playground

HTML

<div class="slide-up">

        <div class="slide-background"></div>
        <div class="blured"></div>
        <div class="slide-content">
             <h2>Pop up title</h2>

            <p>Pretty neat!</p>
        </div>

</div>
<div class="wrapper">
    <div class="content">
         <h1>Some titlehtrytrutrutyutyutyuityuity</h1>

        <div class="image">
            <img src="https://fbcdn-sphotos-a-a.akamaihd.net/hphotos-ak-xpf1/t1.0-9/1970856_10152030148361239_1864148173_n.jpg" />
        </div>
        <p>Lorem ipsum dolor sit amet, consectetur adipiscing elit. Quisque molestie magna elit, quis pulvinar lectus gravida sit amet. Phasellus lacinia massa et metus blandit fermentum. Cras euismod gravida scelerisque. Fusce molestie ligula diam, non porta ipsum faucibus sed. Nam interdum dui at fringilla laoreet. Donec sit amet est eu eros suscipit commodo eget vitae velit.</p>
    </div> <a class="trigger" href="#">trigger slide</a>

</div>
<svg version="1.1" xmlns="http://www.w3.org/2000/svg">
    <filter id="blur">
        <feGaussianBlur stdDeviation="3" />
    </filter>
</svg>

CSS

body {
    margin: 0;
    padding: 0;
    font-family:'Verdana', sans-serif;
    color: #fff;
}
.wrapper {
    position: relative;
    height: 100%;
    overflow: hidden;
    z-index: 100;
    background: #CD535B;
}
img {
    width: 100%;
    height: auto;
}
.blured {
    top: 0;
    height: 0;
    -webkit-filter: blur(3px);
    -moz-filter: blur(3px);
    -ms-filter: blur(3px);
    filter: blur(3px);
    filter: url(#blur);
    filter:progid:DXImageTransform.Microsoft.Blur(PixelRadius='3');
    position: absolute;
    z-index: 1000;
}
.blured .wrapper {
    position: absolute;
    width: inherit;
}
.content {
    width: 300px;
    margin: 0 auto;
}
.slide-up {
    top:10px;
    position: absolute;
    width: 100%;
    z-index: 2000;
    display: none;
    height: auto;
    overflow: hidden;
}


.slide-background {
    position: absolute;
    top: 0;
    width: 100%;
    height: 100%;
    background-color: #fff;
    z-index: 1500;
    opacity: 0.5;
}

JavaScript

var height = $('.slide-up').outerHeight();
var slide_top = parseInt($('.slide-up').css('top'), 10);
$wrapper_width = $('body > .wrapper').css("width");
$('.blured').css("width", $wrapper_width);
$('.trigger').click(function () {
    if ($(this).hasClass('triggered')) {
        $('.blured').animate({
            height: '0px',
        }, 1000, function () {
            $('.blured .wrapper').remove();
        });
        $('.slide-up').slideUp(700);
        $(this).removeClass('triggered');

    } else {
        $('.wrapper').clone().appendTo('.blured');
        $('.slide-up').slideDown(1000);
        $offset = $('.slide-wrapper').offset();
        $('.blured').animate({
            height: $offset.top + height + slide_top + 'px'
        }, 700);
        $('.blured .wrapper').animate({
            left: -$offset.left,
            top: -$offset.top
        }, 100);
        $(this).addClass('triggered');
    }
});