/* Preventy — Elevation & depth
 * Depth is deliberately minimal: a sharp 1px hairline plus the near-white-on-white
 * surface jump is preferred over shadow. When a surface floats, it uses a finely
 * layered, very-low-alpha shadow — never one heavy drop. */
:root{
  --elev-0:none;                                     /* flat: hairline only */
  --shadow-whisper:0px 1px 1px rgba(0,0,0,0.04);     /* level 1 */
  --shadow-floating:0px 2px 2px rgba(15,63,113,0.04),0px 8px 16px -4px rgba(15,63,113,0.08); /* level 2 */
  --elev-1:var(--shadow-whisper);
  --elev-2:var(--shadow-floating);
  --hairline-width:1px;
}