Simple baseline

grid.css

.grid{
  width: 100%;
  height: 100%;
  background-color: #a9a9a9;
  border-top: dotted 1px #000;
  background-image: linear-gradient(90deg, transparent 0px, transparent 1.5px, #fff 1px, #fff 2px),
    linear-gradient(0, transparent 0px, transparent 1px, #fff 1px, #fff 2px);
  background-image: -webkit-linear-gradient(90deg, transparent 0px, transparent 1.5px, #fff 1px, #fff 2px),
    -webkit-linear-gradient(0, transparent 0px, transparent 1px, #fff 1px, #fff 2px);
  background-image: -moz-linear-gradient(90deg, transparent 0px, transparent 1.5px, #fff 1px, #fff 2px),
    -moz-linear-gradient(0, transparent 0px, transparent 1px, #fff 1px, #fff 2px);

  /* Change the below value from '30px' to Npx to set the line-height */
  background-size: 2px 30px;
  position: absolute;
  top: 0;
  left: 0;
  z-index: -1;
}