.ci {
  text-decoration: underline dotted;
  text-underline-offset: 3px;
  text-decoration-thickness: 1px;
  cursor: help;
  color: inherit;              /* garde la couleur du texte courant */

  background-image: linear-gradient(rgba(34, 139, 230, 0.18), rgba(34, 139, 230, 0.18));
  background-size: 0% 100%;       /* au repos : invisible */
  background-repeat: no-repeat;
  transition: background-size 120ms ease;
}

.ci:hover,
.ci:focus-within {
  background-size: 100% 100%;
}

/* Accessibilité : en contraste élevé, remplace le pointillé par un souligné plein */
@media (prefers-contrast: more) {
  .ci { text-decoration-style: solid; }
}

/* Proposition 1 : style carte / clean */
.ci-tooltip {
  background: #fff;
  color: #111;
  border: 1px solid #e6e6e6;
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.12);
  padding: 10px 14px;
  font-size: 14.5px;
  line-height: 1.35;
  border-radius: 6px;
}

.ci-tooltip-arrow {
  background: #fff;
  border: 1px solid #e6e6e6;
  box-shadow: 0 3px 10px rgba(0, 0, 0, 0.08);
}

/* Proposition 2 : Moderne glossy */
/* .ci-tooltip {
  background: rgba(255,255,255,0.25);
  color: #0f172a;
  border: 1px solid rgba(0,0,0,0.06);
  box-shadow: 0 12px 36px rgba(0,0,0,.14);
  padding: 12px 14px;
  font-size: 14.5px;
  line-height: 1.35;
  border-radius: 10px;
  backdrop-filter: blur(8px) saturate(160%);
  -webkit-backdrop-filter: blur(8px) saturate(160%);
}

.ci-tooltip-arrow {
  background: rgba(255,255,255,0.85);
  border: 1px solid rgba(0,0,0,0.06);
  box-shadow: 0 4px 12px rgba(0,0,0,.12);
} */