@media screen and (max-width: 767px){
#main-img{
content:url("img/mobile_homepage.jpg");
}
}
@media screen and (min-width: 768px) {
#main-img{
content:url("img/tablet_homepage.jpg");
}
}
@media (min-width: 992px){
#main-img{
content:url("img/desktop_homepage.jpg");
}
}
@media (min-width: 1200px) {
#main-img{
content:url("img/desktop_homepage.jpg");
}
}
background-size: cover