#voltar-topo{position:fixed;bottom:20px;right:20px;width:50px;height:50px;display:flex;align-items:center;justify-content:center;border-radius:50%;color:#fff;cursor:pointer;z-index:9999;opacity:0;visibility:hidden;transition:opacity 0.3s ease,visibility 0.3s ease}#voltar-topo.show{opacity:1;visibility:visible}