.scroll-down {
    opacity: 1;
    -webkit-transition: all .5s ease-in 3s;
    transition: all .5s ease-in 3s;
}

.scroll-down {
    display: block;
    margin-left: auto;
    margin-right: auto;
    margin-top: 4.5vw;
    width: 48px;
    height: 48px;
    border: 2px solid #FFF;
    background-size: 14px auto;
    border-radius: 50%;
    z-index: 2;
    -webkit-animation: bounce 2s infinite 2s;
    animation: bounce 2s infinite 2s;
    -webkit-transition: all .2s ease-in;
    transition: all .2s ease-in;
    transform: scale(1)
  }
  
  .scroll-down:before {
      position: absolute;
      top: calc(50% - 8px);
      left: calc(50% - 6px);
      transform: rotate(-45deg);
      display: block;
      width: 12px;
      height: 12px;
      content: "";
      border: 2px solid white;
      border-width: 0px 0 2px 2px;
  }
  
  @keyframes bounce {
    0%,
    100%,
    20%,
    50%,
    80% {
      -webkit-transform: translateY(0);
      -ms-transform: translateY(0);
      transform: translateY(0);
    }
    40% {
      -webkit-transform: translateY(-10px);
      -ms-transform: translateY(-10px);
      transform: translateY(-10px);
    }
    60% {
      -webkit-transform: translateY(-5px);
      -ms-transform: translateY(-5px);
      transform: translateY(-5px);
    }
  }