:root{
/* Square by default. Radius exists only for the rare functional control. */
--radius-none:0px;
--radius-subtle:2px;
--radius-pill:999px; /* avoid; documented for exceptions only */

--border-hairline:1px;
--border-strong:2px;
--border-rule:1px solid var(--rule-hairline);
--border-rule-inverse:1px solid var(--rule-hairline-inverse);

/* No shadow system. Depth comes from surface value shifts. */
--shadow-none:none;
--elevation-1:var(--surface-raised);
--elevation-2:var(--surface-panel);
}