#i5510 > div {
  text-align:center;
}
#i5511 img, #i5511 video {
  object-fit:cover;
}
#i5513 {
  background-image:url(../image/contents/guide04.jpeg);
}
#i5512 img, #i5512 video {
  object-fit:cover;
}
#i5515 {
  background-image:url(../image/contents/guide03.jpeg);
}
#i5516 img, #i5516 video {
  object-fit:cover;
}
#i5517 div.box {
  width:33.333%;
}
@media screen and (min-width:641px) and (max-width:835px) {
  #i5517 div.box {
    width:50%;
  }
}
@media screen and (max-width:640px) {
  #i5517 div.box {
    width:50%;
  }
}
#i5517 > div {
  gap: 0%;
}
@media screen and (max-width:640px) {
  #i5517 > div {
    gap:% %;
  }
}