What do you mean fr unit goes from 0 to 100 like percentage ? my solution to level 21 was one 50px column, three columns taking equal share of remaining space,

What do you mean fr unit goes from 0 to 100 like percentage ? my solution to level 21 was one 50px column, three columns taking equal share of remaining space, one 50px column. grid-template-columns:50px 1fr 1fr 1fr 50px;