@keyframes slidy {
  0% { left: 0%; }
  20% { left: 0%; }
  25% { left: -100%; }
  45% { left: -100%; }
  50% { left: -200%; }
  70% { left: -200%; }
  75% { left: -300%; }
  95% { left: -300%; }
  100% { left: -400%; }
  }
  
  div#slider { overflow: hidden; }
  div#slider figure img { width: 20%; float: left; }
  div#slider figure { 
    position: relative;
    width: 500%;
    margin: 0;
    left: 0;
    text-align: left;
    font-size: 0;
    animation: 30s slidy infinite; 
  }