Quick base line grid background pattern.

base-line-grid-bg.scss

$base-line-size: 1.5rem;
$base-line-color: rgba(0,0,0,.35);
$base-line-alt-color: rgba(0,0,0,.15);

html {
  font-size: 100%;
  line-height: 1.5rem;
}

body.base-line-grid {
  background-image: linear-gradient($base-line-color 1px, transparent 1px), linear-gradient($base-line-alt-color 1px, transparent 1px);
  background-size: $base-line-size $base-line-size, $base-line-size $base-line-size;
  background-position: 0 0, $base-line-size/2 $base-line-size/2;
  margin: $base-line-size;
}

h1 {
  font-size: 3rem;
  line-height: 1;
  margin: $base-line-size 0;
}

p {
  font-size: 1rem;
  margin: $base-line-size 0;
}