/* === BOUTON RETOUR EN HAUT ACCESSIBLE === */
.back-to-top {
  position: fixed;
  bottom: 20px;
  left: 50%;
  transform: translateX(-50%);
  width: 50px;
  height: 50px;
  border-radius: 50%;
  border: 2px solid currentColor;
  background: transparent;
  color: #000; /* Adapter selon ton thème pour un contraste suffisant */
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  opacity: 0;
  visibility: hidden;
  transition: opacity 0.3s ease, visibility 0.3s ease;
  z-index: 999;
}

/* Icône */
.back-to-top svg {
  stroke: currentColor;
  width: 24px;
  height: 24px;
}

/* Apparition */
.back-to-top.show {
  opacity: 1;
  visibility: visible;
}

/* Survol (souris) */
.back-to-top:hover {
  background: rgba(0, 0, 0, 0.1);
}

/* Focus clavier (obligatoire WCAG) */
.back-to-top:focus {
  outline: 3px solid #005fcc; /* Contraste fort et visible */
  outline-offset: 3px;
}

/* Respect du prefers-reduced-motion */
@media (prefers-reduced-motion: reduce) {
  .back-to-top {
    transition: none;
  }
}