/* Square corners everywhere. Hierarchy comes from rules, weight and colour — never shadow. */
:root{
  --radius:0;
  --border-width:1px;
  --border-width-accent:2px;
  --border-width-card-accent:3px;
  --rule-section:2px;
  --shadow-none:none;
  --focus-ring:0 0 0 3px var(--color-red-focus);
}