:root{
/* 6px base, doubled — a printer's measure, not a UI grid */
--sp-1:6px;--sp-2:12px;--sp-3:18px;--sp-4:24px;--sp-5:36px;--sp-6:48px;--sp-7:72px;--sp-8:96px;--sp-9:144px;
/* cover geometry: the page is divided in twelfths, the margin is one twelfth */
--cover-w:1200px;--cover-h:1800px;--cover-margin:100px;--cover-col:calc((var(--cover-w) - var(--cover-margin)*2)/12);
--spine-w:112px;
/* the circle motif */
--motif-d:640px;--motif-bar-w:5px;--motif-bar-h:46px;--motif-count:36;
/* lines */
--rule-w-hair:1px;--rule-w-mid:3px;--rule-w-heavy:9px;
/* radii: none. print does not round corners. */
--radius-0:0px;--radius-object:2px;
}