.header .cont .head { background:url(http://webinav.ir/wp-content/uploads/2021/08/wh.png); }
@media screen and (max-width:768px){
.header .cont .head { background-image:url(https://webinav.ir/wp-content/themes/daneshfile_354/img/head-res.jpg);
}
@media screen and (max-width:768px){
.header .cont .head { background-image:url(http://webinav.ir/wp-content/uploads/2021/08/wh.png);
}