calc

https://webref.ru/css/value/calc#comment-3851493027

by akogch

HTML

<div></div>

CSS

div {
  border: 1px solid #000;
  height: 200px;
  background: url(//webref.ru/example/image/figure.jpg) no-repeat;
  background-position: calc(100% - 20%) 0%;
}