.alert-top {
    z-index: 1020!important;
}

.alert:not(.visible) {
    opacity: 0;
}

.alert.visible {
    top: 0;
    opacity: 1;
    animation: fadeIn 0.3s linear;
}

.alert:not(.present) {
    display: none;
}

@keyframes fadeIn {
  0% {
      opacity: 0;
  }
  25%, 50% {
      opacity: 0.5;
  }
  100% {
      opacity: 1;
  }
}