.hairline(@c: #d9d9d9) {
  content: ' ';
  position: absolute;
  top: 0;
  left: 0;
  width: 200%;
  height: 200%;
  transform: scale(0.5);
  transform-origin: 0 0;
  pointer-events: none;
  box-sizing: border-box;
  border: 0 solid @c;
}