Resizable grid overlay in CSS. The `background-size` attribute controls the dimension.

gistfile1.css

.grid {
  background-color: #222222;
  background-image: -webkit-linear-gradient(#444444 1px, transparent 1px), -webkit-linear-gradient(0deg, #444444 1px, transparent 1px);
  background-image: linear-gradient(#444444 1px, transparent 1px), linear-gradient(90deg, #444444 1px, transparent 1px);
  background-size: 10px 10px, 10px 10px;
  border: 1px solid #444444;
  border-width: 0 1px 1px 0;
}