Grid

Composes with the classes `Box` computes instead of replacing them.

How many columns a full row spans. It is the unit `Grid.Col`'s `span` counts against, so changing it rescales every child at once.

The element it paints.

Lets the columns of the last row stretch to fill it instead of leaving a gap on the end. Only affects a row that did not fill up.

Gap between columns and rows. Replaces `gap`, which `Grid` does not accept.

Wraps columns that do not fit onto the next row. Turn it off and they shrink instead, which is what you want for a row that must stay one line.