Skewing both top and bottom of div - html

Question

I am trying to skew both the top and bottom of a div to create a shape that I can then insert a background pattern to however, after a few hours of research I can't really come up with a solid solution. I'm nearly there in the sense that all I need to do is to skew the bottom but am looking for some help or guidance on doing so.
I would like the bottom to mirror the skew of the top. Any suggestions?
#test {
position: relative;
width: 100%;
height: 400px;
}
.bg {
width: 50%;
height: 800px;
-webkit-transition: all 300ms ease-in;
background: black;
border-radius: 80px 0px 0px 80px;
position: absolute;
right: 0;
top: 0;
-ms-transform: skewY(-9deg);
-webkit-transform: skewY(-9deg);
transform: skewY(-9deg);
}
<section id="test">
<div class="bg"></div>
</section>
Example of what I currently have
https://jsfiddle.net/3atsj1e5/

Answer 1

With some rotation and perspective you can do it:
.box {
margin-left: auto;
width: 200px;
height: 450px;
transform-origin: right;
transform: perspective(100px) rotateY(-10deg);
border-radius: 40px 0 0 40px;
overflow: hidden;
}
.box::before {
content: "";
position: absolute;
top: 0;
left: 0;
right: 0;
bottom: 0;
background: url(https://picsum.photos/id/1074/400/800) center/cover;
transform-origin:inherit;
transform: perspective(100px) rotateY(10deg);
}
body {
margin: 0;
background:#eee;
}
<div class="box"></div>