#todayilearned

grid-column & grid-row both support a shorthand “slash” syntax where the first value represents the column or row start and the second value represents the column or row end. This is more concise than explicitly listing start and end positions, but not so terse as the four-way a/b/c/d syntax, which is harder to orient around.

.a {
  grid-column: 1 / 2;
  grid-row: 1 / 2;
}

From Rachel Andrew’s now very outdated (as of 2019) book, Getting Ready for CSS Grid Layout.