Found a little typo in the lesson:
CSS Grid: Use CSS Grid units to Change the Size of Columns and Rows
The 4° paragraph needs to be updated from:
%: adjusts the column or row to the percent width of its container.
%: adjusts the column or row to the percent width or height of its container.
It’s nothing serious, but I thought It may be good just to clarify this before any further misundertandings can happen.