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

.arrow {
  position: absolute;
  bottom: 2em;
  left: 50%;
  margin-left: -20px;
  width: 40px;
  height: 40px;
}

.bounce {
  -moz-animation: bounce 2s infinite;
  -webkit-animation: bounce 2s infinite;
  animation: bounce 2s infinite;
}