.title {background-image : url(../img/pc/en/logo.png);}
.about {background-image : url(../img/pc/en/about.png);}
.screenshots div {background-image : url(../img/pc/en/ss1.jpg);}
.screenshots div + div {background-image : url(../img/pc/en/ss2.jpg);}
.screenshots div + div + div {background-image : url(../img/pc/en/ss3.jpg);}

@media screen and (max-width:640px) {
  .about {background-image : url(../img/sp/en/about.png);height:293px;}
  .screenshots div {background-image : url(../img/sp/en/ss1.jpg);}
  .screenshots div + div {background-image : url(../img/sp/en/ss2.jpg);}
  .screenshots div + div + div {background-image : url(../img/sp/en/ss3.jpg);}  
}