<!DOCTYPE html>
<!-- Nothing on this page should be scrollable. -->
<style>
body {
margin: 0;
}
.red {
background: red;
position: absolute;
width: 100%;
height: 100%;
overflow: hidden;
}
.green {
background: green;
position: absolute;
width: 500px;
height: 100%;
right: 0px;
width: 500px;
transform: translateX(250px);
box-shadow: 0px 0px 200px black;
}
</style>
<div class="red">
<div class="green"></div>
</div>