:root{
  --border-width:2px;              /* every border on the site is 2px */
  --border-bone:2px solid var(--bone);
  --border-rule:2px solid var(--rule);
  --border-flame:2px solid var(--flame);

  --radius-input:12px;
  --radius-button:14px;
  --radius-tile:16px;
  --radius-card:20px;

  --focus-ring:3px solid var(--flame);
  --focus-offset:-1px;

  /* Blockstone uses no box-shadows: separation comes from 2px borders and flat fills. */
  --shadow-none:none;
}