.error-card,
.success-card {
  position: fixed;
  top: 20px;
  right: 20px;
  min-width: 260px;
  padding: 15px 20px;
  border-radius: 6px;
  color: #fff;
  z-index: 9999;
  box-shadow: 0 5px 15px rgba(0,0,0,.2);
}
.d-none{
  display: none;
}

.error-card {
  background-color: #dc3545;
}

.success-card {
  background-color: #28a745;
}