.btn-loading {
  position: relative;
  color: transparent !important; /* Esconde o texto */
  pointer-events: none; /* Opcional: desativa o botão */
}

.btn-loading::after {
  content: "";
  position: absolute;
  top: 50%;
  left: 50%;
  width: 1.5em;
  height: 1.5em;
  margin-top: -0.75em;
  margin-left: -0.75em;
  border: 2px solid #fff;
  border-top: 2px solid #3498db;
  border-radius: 50%;
  animation: btn-spin 0.7s linear infinite;
  z-index: 2;
}

@keyframes btn-spin {
  0% { transform: rotate(0deg);}
  100% { transform: rotate(360deg);}
}