JSFiddle - React, Tailwind, and code Playground

HTML

<a class="lightbox" href="#firstimg"><img src="//placehold.it/200x150"/></a>
<div class="lightbox-target" id="firstimg">
    <img src="//placehold.it/800x600" />
    <a class="lightbox-close" href="#close"></a>
</div>

CSS

/*Eliminates padding, centers the thumbnail */
 body, html {
    padding: 0;
    margin: 0;
    text-align: center;
}
/* Styles the thumbnail */
 a.lightbox img {
    height: 150px;
    border: 3px solid white;
    box-shadow: 0px 0px 8px rgba(0, 0, 0, .3);
    margin: 20px;
}
/* Styles the lightbox, removes it from sight and adds the fade-in transition */
 .lightbox-target {
    position: fixed;
    top: -100%;
    width: 100%;
    background: rgba(0, 0, 0, .7);
    width: 100%;
    opacity: 0;
    -webkit-transition: opacity .5s ease-in-out;
    -moz-transition: opacity .5s ease-in-out;
    -o-transition: opacity .5s ease-in-out;
    transition: opacity .5s ease-in-out;
    overflow: hidden;
}
/* Styles the lightbox image, centers it vertically and horizontally, adds the zoom-in transition and makes it responsive using a combination of margin and absolute positioning */
 .lightbox-target img {
    margin: auto;
    position: absolute;
    top: 0;
    left:0;
    right:0;
    bottom: 0;
    max-height: 0%;
    max-width: 0%;
    border: 3px solid white;
    box-shadow: 0px 0px 8px rgba(0, 0, 0, .3);
    box-sizing: border-box;
    -webkit-transition: .5s ease-in-out;
    -moz-transition: .5s ease-in-out;
    -o-transition: .5s ease-in-out;
    transition: .5s ease-in-out;
}
/* Styles the close link, adds the slide down transition */
 a.lightbox-close {
    display: block;
    width:50px;
    height:50px;
    box-sizing: border-box;
    background: white;
    color: black;
    text-decoration: none;
    position: absolute;
    top: -80px;
    right: 0;
    -webkit-transition: .5s ease-in-out;
    -moz-transition: .5s ease-in-out;
    -o-transition: .5s ease-in-out;
    transition: .5s ease-in-out;
}
/* Provides part of the "X" to eliminate an image from the close link */
 a.lightbox-close:before {
    content:"";
    display: block;
    height: 30px;
    width: 1px;
    background: black;
    position: absolute;
    left: 26px;
    top:10px;
   ...