.box {
  /*background-color: #61ab20;*/
  margin: 0 auto;
  /*width: 500px;*/
  height: 100%;
  position: relative;
  /*box-shadow: inset 0 0 3px #000;*/
  border-radius: 5px;
  /*border: 1px solid #111;*/
  /*overflow: hidden;*/
}
.box b {
  display: block;
  width: 152px;
  height: 98px;
  /*border-radius: 50%;*/
  /*background-color: #3673cf;*/
  background: url("../images/duck.png") no-repeat scroll 0px 0px transparent;
  /*box-shadow: inset -5px -5px 5px rgba(0,0,0,.6), 15px 15px 2px rgba(0,0,0,.04);*/
  position: absolute;
  margin-top: 0px;
  -webkit-animation: moveX 15.05s linear 0s infinite alternate, moveY 20.4s linear 0s infinite alternate;
  -moz-animation: moveX 15.05s linear 0s infinite alternate, moveY 20.4s linear 0s infinite alternate;
  -o-animation: moveX 15.05s linear 0s infinite alternate, moveY 20.4s linear 0s infinite alternate;
  animation: moveX 15.05s linear 0s infinite alternate, moveY 20.4s linear 0s infinite alternate;
}

@-webkit-keyframes moveX {
  from { left: 0; } to { left: 90%; }
}
@-moz-keyframes moveX {
  from { left: 0; } to { left: 90%; }
}
@-o-keyframes moveX {
  from { left: 0; } to { left: 90%; }
}
@keyframes moveX {
  from { left: 0; } to { left: 90%; }
}
@-webkit-keyframes moveY {
  from { top: 0; } to { top: 100%; }
}
@-moz-keyframes moveY {
  from { top: 0; } to { top: 85%; }
}
@-o-keyframes moveY {
  from { top: 0; } to { top: 100%; }
}
@keyframes moveY {
  from { top: 0; } to { top: 85%; }
}