Base element width: 36 (in 400 viewBox) — used for column width, square side, circle diameter, ring stroke. Corner radius: 4 on every rectangle. Padding mode A: framed, ~60 safe margin on all sides. Padding mode B: full bleed, radial fade on all edges (the fade is the padding). Accent: always solid black, applied to a whole element — never as a small dot on top of a gray shape.