body{
  background:#fff;
}
.blue{
  background-color: #4de
}
#blocao{
  position:relative;
  margin:auto;
  width:500px;
  top:0px;
  padding-bottom:20px;
  text-align:center;
  background-color:#fff;
  animation-name:down;
  animation-duration:1s
}
form{
  width:50%;
  margin:auto;
}
input{
  display:block;
  margin:5px;
  width:100%;
  height:50px;
  text-align:center;
}
input[type=submit]{
  width:100%;
}
input[type=submit]:hover{
  text-decoration: none;
}
@keyframes down{
  0%{
    margin-top:-10%;
    opacity:0.3;
  }
  100%{
    margin-top:0;
    opacity:1;
  }
  
}