debug css grid

debug-grid.css

/* DEBUG Grid */
body {
  position: relative;
  background: blue;
}
body:after {
  background-size: var(--grid-size) var(--grid-size);
  background-repeat: repeat;
  background-image:
    linear-gradient(
      var(--transred1) 0%,
      var(--transred1) 1.25%,
      transparent 1.25%,
      transparent 48.75%,
      var(--transred2) 48.75%,
      var(--transred2) 51.25%,
      transparent 51.25%,
      transparent 98.75%,
      var(--transred1) 98.75%,
      var(--transred1) 100%
    ),
    linear-gradient(to right,
      var(--transred1) 0%,
      var(--transred1) 1.25%,
      transparent 1.25%,
      transparent 48.75%,
      var(--transred2) 48.75%,
      var(--transred2) 51.25%,
      transparent 51.25%,
      transparent 98.75%,
      var(--transred1) 98.75%,
      var(--transred1) 100%
    );
  content: '';
  pointer-events: none;
  position: absolute;
  bottom: 0;
  right: 0;
  top: 0;
  left: 0;
  z-index: 9999;
}