main div{
	text-align:center}
@media screen and (min-width:480px) { 
	/*　for iPhone Landscape　(iPhone 横)　*/
	
}
@media screen and (min-width:768px) and ( max-width:1024px) {
	/*　for iPad 　*/
	
}
@media screen and (min-width:1024px) {
	/*　for PC　*/
	
}