/* ====== BOUTON TOP ====== */
#top-btn{
  position:fixed;bottom:26px;right:26px;width:50px;height:50px;border-radius:50%;
  background:var(--grad-or);color:#1a1305;border:none;font-size:1.15rem;cursor:pointer;
  opacity:0;pointer-events:none;transition:opacity .4s,transform .4s;z-index:999;
  box-shadow:var(--ombre-or);font-weight:800;
}
#top-btn.visible{opacity:1;pointer-events:auto}
#top-btn:hover{transform:translateY(-4px)}