/* Flat-by-default: surfaces carry no resting shadow. Depth comes from tonal
   layering (night-core → deep-navy → canvas-light). Shadows exist only as
   interaction signals, and every one is tinted tech-blue — never gray/black. */
:root {
  --shadow-glow-nav: 0 0 22px rgba(55, 138, 221, 0.40);
  --shadow-glow-primary: 0 0 28px rgba(55, 138, 221, 0.50);
  --shadow-glow-cta: 0 0 36px rgba(55, 138, 221, 0.55);
  --shadow-card-lift: 0 16px 48px rgba(55, 138, 221, 0.08);
  --shadow-icon-ambient: drop-shadow(0 0 20px rgba(55, 138, 221, 0.28));
}