<section>
<p>SCROLL DOWN CSS</p>
<a href="#" class="scroll-down" address="true"></a>
</section>
<section class="ok">
<p>OK SCROLL !</p>
</section>

body {
  background-color: #000;
}

*,
:after,
:before {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

section {
  height: 100vh;
  width: 100%;
  display: table;
  
}
section.ok{
  background-color: #555;
}

p{
  color: white;
  font-family: arial;
  display: table-cell;
  text-align: center;
  vertical-align: middle;
}

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

.scroll-down {
  position: absolute;
  bottom: 30px;
  left: 50%;
  margin-left: -16px;
  display: block;
  width: 32px;
  height: 32px;
  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);
  }
}

 $(function() {
    $('.scroll-down').click (function() {
      $('html, body').animate({scrollTop: $('section.ok').offset().top }, 'slow');
      return false;
    });
  });