:root {
  --popup-window-overlay: rgba(31, 31, 32, .22);
}

.overlay {
  left: 0;
  top: 0;
  transition: opacity 0.2s ease-out;
  width: 100%;
  background-color: var(--popup-window-overlay);
  height: 100vh;
  position: fixed;
  z-index: 100;
  opacity: 0;
  visibility: hidden;
}
.overlay.visible {
  opacity: 1;
  visibility: visible;
}