But that's not all you can do.
There are ongoing discussions for adding more options to control the direction of your layout.
This is very similar to flexbox where you can choose an orientation, and a starting position
with row/column or row-reverse/column-reverse.
With grid-lanes, same idea, you pick an orientation: row/column.
And a direction to fill the layout: left/right for row, or top/bottom for column.