JSFiddle - React, Tailwind, and code Playground

HTML

<div class="outer">
    <div class="inner">
        <p>Paragraph text.</p>                
    </div>
</div>

CSS

.outer {
    background-color: #000;  
    position: fixed;
    top: 0;
    left: 0;
    z-index: 9998;
    height: 100%;
    width: 100%;
    opacity: 0.5;
}

.inner {
    background-color: blue;
    width: 240px;
    position: fixed;
    z-index: 9999;
    left: 50%;
    top: 50%;
    margin-left: -300px;
    margin-top: -150px;
}

JavaScript

$(".outer")
    .on("click", function () {
        $(this).find(".inner").slideUp();
    })
    .on("click", ".inner", function (event) {
        event.stopPropagation();
    });