Plain square grid
square-grid-v1A uniform square lattice with an optional heavier major line every N cells and optional centre axes. Columns and rows are the floor of the usable dimension divided by the requested spacing; leftover space is reported, never absorbed.
- usable = page − left margin − right margin (and top/bottom)
- columns = floor(usable width / spacing)
- rows = floor(usable height / spacing)
- line xᵢ = left + i · spacing, i = 0 … columns