.bounce {
  position:fixed;
  left:50%;
  bottom:0;
  margin-top:-25px;
  margin-left:-25px;
  height:50px;
  width:50px;
  background: url(../images/misc/arrow.png);
  -webkit-animation:bounce 1s infinite;
  -moz-animation:bounce 1s infinite;
  -o-animation:bounce 1s infinite;
  animation:bounce 1s infinite;

}

@-webkit-keyframes bounce {
  0%       { bottom:0px; }
  50%      { bottom:15px; }
  100%     {bottom:30;}
}

 @-moz-keyframes bounce {
  0%       { bottom:0px; }
  50%      { bottom:15px; }
  100%     {bottom:30;}
}

 @-o-keyframes bounce {
  0%       { bottom:0px; }
  50%      { bottom:15px; }
  100%     {bottom:30;}
}

 @keyframes bounce {
  0%       { bottom:0px; }
  50%      { bottom:15px; }
  100%     {bottom:30;}
}