body{
    position: relative;
    height: 100%;
    overflow:hidden;
  }
  
  #logo{
    display:block;
    width: 70vw;
    height: 50%;
    overflow: hidden;
    margin: auto;
    position: absolute;
    top: 0; left: 0; bottom: 0; right: 0;

    -webkit-animation: fadein 1.618s;
    -moz-animation: fadein 1.618s;
    -ms-animation: fadein 1.618s;
    -o-animation: fadein 1.618s;
    animation: fadein 1.618s;
    animation-timing-function: ease;
}


@keyframes fadein {
    from { opacity: 0; top: -200px; }
    to   { opacity: 1; top: 0; }
}

@-moz-keyframes fadein {
    from { opacity: 0; top: -200px; }
    to   { opacity: 1; top: 0; }
}

@-webkit-keyframes fadein {
    from { opacity: 0; top: -200px; }
    to   { opacity: 1; top: 0; }
}

@-ms-keyframes fadein {
    from { opacity: 0; top: -200px; }
    to   { opacity: 1; top: 0; }
}

@-o-keyframes fadein {
    from { opacity: 0; top: -200px; }
    to   { opacity: 1; top: 0; }
}