CSS Hack for making borders any size

gistfile1.sass

//produces a 100px box with 80px right border

div{
  height: 100px;
  position:relative;
  &:after {
    content: '';
    position: absolute;
    height: 80%;
    border-right: 2px solid red;
    right: 1px;
    top: 1px;
  }
}