.modal {
  display: flex;
  justify-content: center;
  align-items: start;
  height: 100%;
  position: fixed;
  width: 100%;
  top: 0;
  visibility: hidden;
  opacity: 0;
  transition: all 0.3s ease;
  z-index: 1000;
}
.modal .modal-backdrop {
  background: rgba(0, 0, 0, 0.7);
  height: 100%;
  width: 100%;
  position: fixed;
}
.modal .modal-content {
  position: relative;
  top: -100%;
  transition: all 0.6s ease;
}
.modal.visible {
  opacity: 1;
  visibility: visible;
  overflow-y: scroll;
}
.modal.visible .modal-content {
  top: 0;
}