Stack
A layout primitive that arranges children along a single axis — vertical or horizontal — with consistent spacing between them.
Example usage
“Build the form as a vertical stack with 16px gaps instead of margining each field by hand.”
Editor’s note
Stacks replace margin arithmetic with one spacing decision, which is why every
modern design system is built on them. The discipline is keeping spacing on
the container (gap), never on the children — the moment items carry their
own margins, the system leaks.