html, body {
  color: white;
}
.ldldl {
  background-image: linear-gradient(
      to top,
      #000 0%,
      #000 50%,
      transparent 50%,
      transparent 100%
  ),
  linear-gradient(to right, transparent 0%, transparent 50%, #000 50%, #000 100%);
  background-size: 50px 50px;
}