:root{
  --radius-xs:2px;
  --radius-sm:4px;
  --radius-md:8px;
  --radius-lg:16px;
  --radius-xl:28px;
  --radius-pill:999px;
  --radius-arch:999px 999px 4px 4px;       /* full cove arch — hairline frames, imagery, tiles */
  --radius-arch-soft:96px 96px 4px 4px;    /* filled panels: a domed top that still holds text */
}