.lightbox {
  display: none;
  position: fixed;
  top: 0;
  left: 0;
  z-index: 100;
  width: 100vw;
  height: 100vh;
  min-height: 100vh;
  overflow-y: scroll;
  background-color: rgba(0, 0, 0, 0.7);
}
.lightbox.show {
  display: block;
}