@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%; }
    }
    
    body { margin: 0; } 
    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; 
    }