JSFiddle - React, Tailwind, and code Playground
HTML
<div id="top-element">Some div that has greater width than the inner div</div>
<div id="iframe-wrapper">
<iframe src="http://www.apple.com/" scrolling="auto"></iframe>
</div>
CSS
div#iframe-wrapper {
position: fixed;
top: 150px;
left: 300px;
right:300px;
bottom: 45px;
width: 200px;
}
div#iframe-wrapper iframe {
position: absolute;
top: 0;
bottom: 0;
left: 0;
right: 100px;
height: 100%;
width: 100%;
}
div#top-element{
width: 800px;
color: black;
background: orange;
}
}