#intro img{
  display: block;
  margin: 0 auto;
}

#features img{
  display: block;
  margin: 0 auto;
}

/*PC用*/
@media print, screen and (min-width: 641px){

#intro img{
  width:75%;
}

#features img.mb-5 {
  width: 75%;
}


}

/*SP用*/
@media screen and (max-width:640px) {


#intro img{
  display: block;
  margin-bottom:16px;
}

}