.main_image_{
  margin-bottom: 40px;
}
.main_image_ img{
  width: 100%;
  height: auto;
}
.thumbnail{
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}
.thumbnail + .thumbnail{
  margin-top: 30px;
}
.thumbnail_ttl{
  width: 191px;
}
.thumbnail_cont{
  width: 699px;
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}
.thumbnail_cont .thumbnail_image{
  width: calc((100% - 30px) / 4);
}

@media (max-width:768px){
.main_image_{
  margin-bottom: 30px;
}
.thumbnail_ttl{
  width: calc((100% - 10px) * 0.343);
}
.thumbnail_cont{
width: calc((100% - 10px) * 0.657);
}
.thumbnail_cont .thumbnail_image{
  width: calc((100% - 20px) / 2);
}

}