JSFiddle - React, Tailwind, and code Playground
HTML
<div id="sb-body">
<a id="sb-nav-previous" class="sb-bignav" title="Previous" onclick="Shadowbox.previous()">
<span class="sb-img-next"></span>
<span class="sb-img-previous"></span>
</a>
<a id="sb-nav-next" class="sb-bignav" title="Next" onclick="Shadowbox.next()">
<span class="sb-img-previous"></span>
<span class="sb-img-next"></span>
</a>
<div id="sb-body-inner">
<img style="position: absolute;" src="http://www.element17.com/gallery/01_CONSTRUCTS/Shear.jpg" id="sb-player" height="405" width="609">
</div>
</div>
CSS
#sb-nav-next {
right:0;
}
#sb-nav-previous {
left:0;
}
#sb-body:hover .sb-bignav {
opacity:0.5;
-webkit-opacity:0.5;
-moz-opacity:0.5;
}
#sb-nav-next:hover #sb-nav-previous,
#sb-nav-previous:hover #sb-nav-next {
opacity:0;
-webkit-opacity:0;
-moz-opacity:0;
}
.sb-bignav {
cursor:pointer;
position:absolute;
width:200px;
height:100%;
top:0;
z-index:400;
opacity:0;
-webkit-opacity:0;
-moz-opacity:0;
transition: opacity .125s ease-in;
-webkit-transition: opacity .125s ease-in;
-moz-transition: opacity .125s ease-in;
}
.sb-bignav:hover {
opacity:1.0;
-webkit-opacity:1.0;
-moz-opacity:1.0;
}
.sb-img-previous{
background:url('http://www.element17.com/images/nav-left.png') center center no-repeat;
}
.sb-img-next{
background:url('http://www.element17.com/images/nav-right.png') center center no-repeat;
}
.sb-img-previous,.sb-img-next{
position: fixed;
width: 200px;
height:100%;
}
.sb-img-previous{
left:0;
}
.sb-img-next{
right:0;
}
#sb-nav-previous .sb-img-next{
right:0;
pointer-events: none;
}
#sb-nav-next .sb-img-previous{
left:0;
pointer-events: none;
}
#sb-nav-previous .sb-img-next,
#sb-nav-next .sb-img-previous,
#sb-nav-previous:hover .sb-img-previous,
#sb-nav-next:hover .sb-img-next{
opacity: 1;
}
#sb-nav-previous .sb-img-previous,
#sb-nav-next .sb-img-next,
#sb-nav-previous:hover .sb-img-next,
#sb-nav-next:hover .sb-img-previous{
opacity: 0;
}