#arrow-down {
  position: relative;
  margin: 0 auto;
  text-align: center;

}
.fa-angle-down {
      content: '\f0a8';
      font-family: 'Font Awesome 5 Free';
      font-size: 80px;
      transition: .3s ease-in-out;
  }

.fa-angle-down:hover {
      opacity: 0.7;
      transition: .3s ease-in-out;
  }


.fa, .fas {
  color: crimson;
}

.fa-angle-down {
    animation-name: move_arrow;
    animation-duration: 1.4s;
    animation-timing-function: linear;
    animation-iteration-count: infinite;
    animation-play-state: running;
    position: relative;
}


@keyframes move_arrow{
  0% {
    top: 5px;
}
25% {
    top: 15px;
}
50% {
    top: 20px;
}
75% {
    top: 15px;
}
100% {
    top: 5px;
}
    }