M · 6 × 3 rows
Drag the header to move · drag the corner to resize — both snap to the grid
Widths are S · M · L · XL (3, 6, 9 or 12 of 12 columns). Heights are multiples of 108px: a card is 108, a chart 324. Each kind allows only some sizes; each dot is a size the widget can snap to from where it sits.