<!DOCTYPE html>
<!-- https://github.com/servo/servo/issues/9309 -->
<style>
body {
margin: 0;
}
.a {
background: red;
width: 100%;
height: 100%;
position: absolute;
overflow: hidden;
}
.b {
background: green;
width: 40px;
height: 40px;
position: absolute;
right: -40px;
}
</style>
<div class="a">
<div class="b"></div>
</div>