/* Public design system. Dark defaults in the shared document head; light remains available. */
:root,[data-theme="light"] {
  color-scheme: light;
  --bg:#f7f9fc; --surface:#fff; --surface-soft:#edf3fc; --text:#14243d;
  --muted:#5d6c82; --primary:#245dd8; --accent:#16788f; --border:#dce4ee;
  --header:rgba(255,255,255,.92); --shadow:0 20px 65px rgba(38,65,105,.08);
  --node-start:#dceaff; --node-end:#edf4ff; --node-mint:#e2f3f1; --diagram-line:#b9cce4;
  --success:#15734e; --success-bg:#edf8f1; --error:#b52d45; --error-bg:#fff0f2;
  --display:Fraunces,Georgia,serif; --body:Inter,system-ui,sans-serif;
}
[data-theme="dark"] {
  color-scheme:dark;
  --bg:#080f21; --surface:#101c33; --surface-soft:#142440; --text:#edf3ff;
  --muted:#acbad2; --primary:#83b2ff; --accent:#76d6e8; --border:#293b57;
  --header:rgba(8,15,33,.93); --shadow:0 20px 65px rgba(0,0,0,.2);
  --node-start:#1a3b68; --node-end:#162c4c; --node-mint:#143d46; --diagram-line:#3f6189;
  --success:#8be0b9; --success-bg:#11372e; --error:#ffb0bc; --error-bg:#3b2130;
}