.loading {
  position: relative;
}

.loading .btn-txt {
  display: none;
}

.loading:after {
  content: "";
  position: absolute;
  border-radius: 100%;
  top: 50%;
  width: 0;
  height: 0;
  border: 2px solid rgba(255, 255, 255, 0.5);
  border-left-color: #FFF;
  border-top-color: #FFF;
  animation: spin .6s infinite linear, grow .3s forwards ease-out;
}

@keyframes spin {
  to {
    transform: rotate(359deg);
  }
}

@keyframes grow {
  to {
    width: 20px;
    height: 20px;
    margin-top: -8px;
  }
}