@-webkit-keyframes slideRight{
  from{-webkit-transform:translateX(-20px)}
  to{-webkit-transform:translateX(0)}
}
@-moz-keyframes slideRight{
  from{-moz-transform:translateX(-20px)}
  to{-moz-transform:translateX(0)}
}
@-o-keyframes slideRight{
  from{-o-transform:translateX(-20px)}
  to{-o-transform:translateX(0)}
}
@keyframes slideRight{
  from{transform:translateX(-20px)}
  to{transform:translateX(0)}
}
@-webkit-keyframes slideLeft{
  from{-webkit-transform:translateX(20px)}
  to{-webkit-transform:translateX(0)}
}
@-moz-keyframes slideLeft{
  from{-moz-transform:translateX(20px)}
  to{-moz-transform:translateX(0)}
}
@-o-keyframes slideLeft{
  from{-o-transform:translateX(20px)}
  to{-o-transform:translateX(0)}
}
@keyframes slideLeft{
  from{transform:translateX(20px)}
  to{transform:translateX(0)}
}
@-webkit-keyframes fadeIn{
  from{opacity:0}to{opacity:1}
}
@-moz-keyframes fadeIn{
  from{opacity:0}to{opacity:1}
}
@-o-keyframes fadeIn{
  from{opacity:0}to{opacity:1}
}
@keyframes fadeIn{
  from{opacity:0}to{opacity:1}
}
#left{
  display: inline-block;
  -webkit-animation: slideRight 1500ms ease 1200ms, fadeIn 1500ms ease 1400ms;
  -moz-animation: slideRight 1500ms ease 1200ms, fadeIn 1500ms ease 1400ms;
  -o-animzation: slideRight 1500ms ease 1200ms, fadeIn 1500ms ease 1400ms;
  animation: slideRight 1500ms ease 1200ms, fadeIn 1500ms ease 1400ms;
  -webkit-animation-fill-mode: backwards;
  -moz-animation-fill-mode: both;
  -o-animation-fill-mode: both;
  animation-fill-mode: both;
}
#right{
  display: inline-block;
  -webkit-animation: slideLeft 1500ms ease 1200ms, fadeIn 1500ms ease 1400ms;
  -moz-animation: slideLeft 1500ms ease 1200ms, fadeIn 1500ms ease 1400ms;
  -o-animzation: slideLeft 1500ms ease 1200ms, fadeIn 1500ms ease 1400ms;
  animation: slideLeft 1500ms ease 1200ms, fadeIn 1500ms ease 1400ms;
  -webkit-animation-fill-mode: both;
  -moz-animation-fill-mode: both;
  -o-animation-fill-mode: both;
  animation-fill-mode: both;
}

<div id="left">
  /* some content */
</div>
<div id="right">
  /* some content */
<div>