body {
  animation: 10000ms ease-in-out infinite color-change;
}

.in {
  opacity: 1;
  animation-name: fadeInOpacity;
  animation-iteration-count: 1;
  animation-timing-function: ease-in;
  animation-duration: 5s;
  text-align: center;
  position: absolute;
  left: 50%;
  top: 50%;
  transform: translate(-50%, -50%);
}

.button {
  border: solid;
  color: white;
  padding: 15px 32px;
  text-align: center;
  text-decoration: none;
  display: inline-block;
  font-size: 16px;
  margin: 4px 2px;
  cursor: pointer;
  background-color: #7289da;
  position: absolute;
  left: 46%;
  top: 40%;
}

@keyframes fadeInOpacity {
  0% {
    opacity: 0;
  }
  75% {
    opacity: 0;
  }
  100% {
    opacity: 1;
  }
}

@keyframes color-change {
  0% {
    background-color: wheat;
  }
  50% {
    background-color: coral;
  }
  100% {
    background-color: wheat;
  }
}