.animation {
  opacity: 0;
  -webkit-transition: opacity 0.5s ease-in;
  -moz-transition: opacity 0.5s ease-in;
  -o-transition: opacity 0.5s ease-in;
  -ms-transition: opacity 0.5s ease-in;
  transition: opacity 0.5s ease-in;
}

.animation__fade {
  opacity: 1;
}