.hairline(@c: #d9d9d9) {
    content: " ";
    position: absolute;
    top: 0;
    left: 0;
    width: 200%;
    height: 200%;
    transform: scale(.5);
    transform-origin: 0 0;
    pointer-events: none;
    box-sizing: border-box;
    border: 0 solid @c;
}