.slideshow {
  margin: 0px auto;
  margin-top:90px;
  width: 100%;
  height: auto;
  overflow: hidden;
  border-bottom: 10px solid;
  border-top-color: #856036;
  border-left-color: #5d4426;
  border-bottom-color: #856036;
  border-right-color: #5d4426;
  z-index: 0;
  position:relative;
}

.photo {
  position:absolute;
  width:100%;
  height:auto;
  background-size: cover;
    background-position: 50% 50%;
    background-repeat: no-repeat; 
  animation: round 16s infinite;
  opacity: 0;
}
@media (min-width: 1024px) {
  .slideshow {
    height: 500px;
  }.photo {
  height:100%;
}
}
@media only screen and (min-width: 768px) and (max-width: 1024px) {
  .slideshow {
    height: 400px;
  }
  .photo {
  height:400px;
}
}
@media only screen and (min-width: 600px) and (max-width: 767px) {
  .slideshow {
    height: 300px;
  }.photo {
  height:300px;
}
}
@media only screen and (min-width: 500px) and (max-width: 599px) {
  .slideshow {
    height: 260px;
  }.photo {
  height:260px;
}
}
@media only screen (max-width: 400px) {
  .slideshow {
    height: 200px;
  }.photo {
  height:200px;
}
}

@keyframes round {
  25% {
    opacity: 1;
  }
  40% {
    opacity: 0;
  }
}
img:nth-child(1) {
  animation-delay: 18s;
}

img:nth-child(2) {
  animation-delay: 12s;
}

img:nth-child(3) {
  animation-delay: 6s;
}

img:nth-child(4) {
  animation-delay: 0s;
}