<div class="arrow bounce">
  <a class="fa fa-arrow-down fa-2x" href="#"></a>
</div>

@bg: #2d2d37; // Dark blue
@primary: #fd6b21; // Orange

body { background: @bg;}
a { color: white; text-decoration: none; }

.arrow {
  text-align: center;
  margin: 8% 0;
}
.bounce {
  -moz-animation: bounce 2s infinite;
  -webkit-animation: bounce 2s infinite;
  animation: bounce 2s infinite;
}

@keyframes bounce {
  0%, 20%, 50%, 80%, 100% {
    transform: translateY(0);
  }
  40% {
    transform: translateY(-30px);
  }
  60% {
    transform: translateY(-15px);
  }
}