body {
  font-family: "Sawarabi Mincho";
  margin-right: auto;
  margin-left: auto;
}

@keyframes ginnan_slide {
  0% {opacity:0}
  5% {opacity:1}
  10% {opacity:1}
  20% {opacity:0}
}

#iframe_image {
  width:100%;
  height:480px;
  position: relative;/*親要素基準とする為*/
}

#iframe_image img.slide {
  animation: ginnan_slide 30s infinite;
  opacity: 0;
  position: absolute;
  top : 0;
  left: 0;
  right: 0;
  bottom: 0;
  margin: auto;
  width: 640px;
  height: 480px;
}

#frame_image img:nth-of-type(1){
  animation-delay:0s;
}
#iframe_image img:nth-of-type(2){
  animation-delay:3s;
}
#iframe_image img:nth-of-type(3){
  animation-delay:6s;
}
#iframe_image img:nth-of-type(4){
  animation-delay:9s;
}
#iframe_image img:nth-of-type(5){
  animation-delay:12s;
}
#iframe_image img:nth-of-type(6){
  animation-delay:15s;
}
#iframe_image img:nth-of-type(7){
  animation-delay:18s;
}
#iframe_image img:nth-of-type(8){
  animation-delay:21s;
}
#iframe_image img:nth-of-type(9){
  animation-delay:24s;
}
#iframe_image img:nth-of-type(10){
  animation-delay:27s;
}