:root{
  --radius-xs:4px;      /* chart bar caps */
  --radius-sm:8px;      /* list rows, focus rings */
  --radius-md:12px;     /* icon tiles, small inputs */
  --radius-lg:14px;     /* compact cards, stat cards, pickers */
  --radius-xl:16px;     /* standard app card */
  --radius-2xl:18px;    /* breathing strip, step cards */
  --radius-3xl:20px;    /* the default card radius — web + app */
  --radius-4xl:24px;    /* sheets, game boards */
  --radius-5xl:26px;    /* primary CTA pill on tall buttons */
  --radius-6xl:28px;    /* the anxiety button */
  --radius-7xl:32px;    /* fullscreen game surfaces */
  --radius-device:44px; /* iPhone bezel in .device */
  --radius-pill:100px;  /* buttons, chips, badges — Capsule() */
  --radius-full:9999px;

  /* Border widths — the app draws hairlines at 0.5pt, the web at 1px */
  --border-hair:0.5px;
  --border-thin:1px;
}