div.waiting
  img.bird(src='https://images.unsplash.com/photo-1517516433317-4de48d8eb15b?ixlib=rb-1.2.1&q=85&fm=jpg&crop=entropy&cs=srgb&ixid=eyJhcHBfaWQiOjE0NTg5fQ' alt='Bird.')

* {
  padding: 0;
  margin: 0;
}

.bird {
  display: block;
  min-height: 100vh;
  width: 100vmax;
  object-fit: cover;
  object-position: center right;
}

.waiting {
  height: 100vh;
  width: 100vw;
  overflow: hidden;
  font-size: 2rem;
  position: relative;
  
  &:after {
    content: "Waiting.";
    position: absolute;
    top: 0;
    right: 0;
    bottom: 0;
    left: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    background-color: rgba(255,255,255,.75);
    color: Tomato;
    animation: waiting 3s steps(3, end) infinite;
  } 
}

@keyframes waiting {
  33% {
    content: "Waiting..";
  }
  66% {
    content: "Waiting...";
  }
}