JSFiddle - React, Tailwind, and code Playground
HTML
<p> Click <a href = "javascript:void(0)" onclick = "document.getElementById('light').style.display='block';document.getElementById('fade').style.display='block'">here</a></p>
<div id="light" class="white_content">
<iframe src="iframe.html" width="100%" height="100%" name="frame1" id="frame1" scrolling="auto" frameborder="0"></iframe>
</div>
<div id="fade" class="black_overlay"></div>
CSS
.black_overlay{
display: none;
position: absolute;
top: 0%;
left: 0%;
width: 100%;
height: 100%;
background-color: black;
z-index:1001;
-moz-opacity: 0.8;
opacity:.80;
filter: alpha(opacity=80);
}
.white_content {
display: none;
/*position: absolute;
top: 20%;
left: 25%; */
margin-left: auto;
margin-right: auto;
margin-top: 75;
width: 100%;
height: 100%;
/*border: 10px solid black; */
background-color: black;
z-index:2002;
overflow: auto;
position:relative;
}