body {
 
}
body .arrows {
  position: relative;
  /**/
  position: absolute;
  top: 90%;
  left: 50%;
  /**/
  width: 50px;
  height: 50px;
  transform: translate(-50%, -50%);
}
body .arrows:before {
  content: '';
  position: absolute;
  width: 50px;
  height: 50px;
  border-left: 10px solid rgba(0, 0, 0, 0.7);
  border-bottom: 10px solid rgba(0, 0, 0, 0.7);
  transform: translate(26.66667px, 106.66667px) rotate(-45deg);
  animation: arrows 3s linear infinite;
}
body .arrows:after {
  content: '';
  position: absolute;
  width: 50px;
  height: 50px;
  border-left: 26.66667px solid rgba(0, 0, 0, 0.7);
  border-bottom: 26.66667px solid rgba(0, 0, 0, 0.7);
  transform: translate(53.33333px, 0px) rotate(-45deg);
  animation: arrows 3s linear infinite -1.5s;
}

@keyframes arrows {
  0% {
    border-left: 10px solid transparent;
    border-bottom: 10px solid transparent;
    transform: translate(-13.33333px, -53.33333px) rotate(-45deg);
  }
  10%, 90% {
    border-left: 10px solid transparent;
    border-bottom: 10px solid transparent;
  }
  50% {
    border-left: 10px solid rgba(255, 255, 255, 0.7);
    border-bottom: 10px solid rgba(255, 255, 255, 0.7);
    transform: translate(-13.33333px, 0px) rotate(-45deg);
  }
  100% {
    border-left: 10px solid transparent;
    border-bottom: 10px solid transparent;
    transform: translate(-13.33333px, 53.33333px) rotate(-45deg);
  }
}