<!DOCTYPE html>
<style>
div {
  position: absolute;
  top: 50px;
  left: 50px;
  width: 100px;
  height: 100px;
  outline: green solid 5px;
  outline-offset: 10px;
}

</style>

Box should be repainted when outline-offset style changes. Passes if no red.
<div id="target"></div>