<!DOCTYPE html>
<style>
#grandparent {
width: 200px; height: 200px; overflow: hidden; border-radius: 25px;
background-color: yellow;
}
#parent { position: relative; left: 30px; top: 30px; width: 200px;
height: 200px; overflow: hidden; background-color: blue;
}
#child { position: relative; left: 10px; top: 10px; width: 120px;
height: 120px; background-color: gray; will-change: transform;
}
#grandchild { position: relative; left: 10px; top: 10px; width: 200px;
height: 200px; background-color: green;
}
</style>
<div id='grandparent'>
<div id='parent'>
<div id='child'>
<div id='grandchild'></div>
</div>
</div>
</div>