/* Retour au sommet - lien natif, sans JavaScript ni collecte. */
a.iris-scrolltop {
  position: fixed;
  z-index: 110;
  right: max(14px, calc(env(safe-area-inset-right, 0px) + 10px));
  bottom: max(14px, calc(env(safe-area-inset-bottom, 0px) + 10px));
  display: grid;
  place-items: center;
  width: 42px;
  height: 42px;
  border: 1px solid #79766d;
  border-radius: 50%;
  background: #faf9f5;
  color: #252a27;
  box-shadow: 0 3px 12px rgba(0,0,0,.15);
  font: 700 23px/1 Georgia,serif;
  text-decoration: none;
  cursor: pointer;
}
a.iris-scrolltop:hover { background: #e5dbc9; color: #1d2623; border-color: #4c4439; }
a.iris-scrolltop:focus-visible { outline: 3px solid #007c89; outline-offset: 4px; }
@media (max-width: 420px) {
  a.iris-scrolltop {
    width: 38px; height: 38px; font-size: 22px;
    right: max(12px, calc(env(safe-area-inset-right, 0px) + 9px));
    bottom: max(12px, calc(env(safe-area-inset-bottom, 0px) + 9px));
  }
}
@supports (animation-timeline: scroll()) {
  a.iris-scrolltop {
    animation: iris-scrolltop-reveal linear both;
    animation-timeline: scroll(root block);
    animation-range: 150px 350px;
  }
  @keyframes iris-scrolltop-reveal {
    from {opacity: 0; visibility: hidden;}
    to {opacity: 1; visibility: visible;}
  }
}