#Container  {
  display:block; width:600px; height:400px; overflow:hidden; background-color:#000;
  padding:0;
}
.Change {
  display:block; position:absolute; height:1.6em; width:1.6em; background-color:rgba(0, 0, 0, 0.3);
  top:0; color:#0FF; text-align:center; font-size:120%; user-select:none; cursor:pointer;
}
#F {
  right:0; top:44%; z-index:4;
}
#B {
  left:0; top:44%; z-index:4;
}
#Pause {
  display:block; position:absolute; top:1%; width:10%; margin:0 44%;
  background-color:rgba(255, 255, 255, 0.5); padding:6px;
  text-align:center; z-index:4; user-select:none; cursor:pointer;
}
.Caption {
  width:100%;
  position:relative;
  color:#FFF;
  bottom:3em;
  background-color:rgba(0, 0, 0, 0.4);
  padding:6px;
  text-align:center;
  z-index:1;
  display:none;
}
.Slide {
  width:100%; height:auto;
  animation-duration:2s;
  animation-name:none;
  z-index:1;
  display:inline-block;
  position:absolute;
  transform:translate(0, calc(50vh - 55%));
}
.Slide:first-child {display:block;}
.Caption:first-of-type {display:block;}

@keyframes move1x {
  0% {transform:translate(100%, calc(50vh - 55%));}
  100% {transform:translate(0, calc(50vh - 55%));}
}
@keyframes move2x {
  0% {transform:translate(0, calc(50vh - 55%));}
  100% {transform:translate(-100%, calc(50vh - 55%));}
}
@keyframes move3x {
  0% {transform:translate(-100%, calc(50vh - 55%));}
  100% {transform:translate(0, calc(50vh - 55%));}
}
@keyframes move4x {
  0% {transform:translate(0, calc(50vh - 55%));}
  100% {transform:translate(100%, calc(50vh - 55%));}
}

@media (max-aspect-ratio: 4/3) {
  .Slide {height:100%; width:auto; transform:translateX(calc(50vw - 50%));}
  @keyframes move1x {
    0% {transform:translateX(calc(50vw + 50%));}
    100% {transform:translateX(calc(50vw - 50%));}
  }
  @keyframes move2x {
    0% {transform:translateX(calc(50vw - 50%));}
    100% {transform:translateX(calc(-50vw - 50%));}
  }
  @keyframes move3x {
    0% {transform:translateX(calc(-50vw - 50%));}
    100% {transform:translateX(calc(50vw - 50%));}
  }
  @keyframes move4x {
   0% {transform:translateX(calc(50vw - 50%));}
   100% {transform:translateX(calc(50vw + 50%));}
  }
}