.loading-screen {
  display: flex;
  justify-content: center;
  align-items: center;
  position: absolute;
  left: 0;
  top: 0;
  z-index: 1000;
  width: 100%;
  height: 100%;
  background: rgba(0,0,0,0.7);
  opacity: 0;
  transition: opacity 300ms;
}

.loading-screen.visible {
  opacity: 1;
}