Template:Infobox NaviCust part/grid/styles.css

Template page
.navicust-grid {
  display: grid;
  grid-template-columns: repeat(7, 30px);
  grid-template-rows: repeat(7, 30px);
  grid-column-gap: 2px;
  grid-row-gap: 2px;
  margin: 1rem auto;
  background: black;
  border: 2px solid black;
}

.navicust-grid__cell {
	background-color: gray;
	color: transparent;
	text-align: center;
}

.navicust-grid__cell-filled {
	background-color: red;
}