@import url(https://fonts.googleapis.com/css?family=Istok+Web);
@keyframes slidy {
0% { left: 0%; }
20% { left: 0%; }
25% { left: -100%; }
45% { left: -100%; }
50% { left: -200%; }
70% { left: -200%; }
75% { left: -300%; }
80% { left: -300%; }
95% { left: -400%; }
100% { left: -400%; }
}

div#captioned-gallery { 
  width: 100%; overflow: hidden; 
}
figure.slider { 
  position: relative; width: 500%;
  font-size: 0; animation: 30s slidy infinite; 
}
figure.slider figure { 
  width: 20%; height: auto;
  display: inline-block;  position: inherit; 
}
figure.slider img { width: 100%; }
figure.slider figure figcaption { 
  position: absolute; bottom: 0;
  background: rgba(0,0,0,0.4);
  color: #fff; width: 100%;
  font-size: 2rem;
}