@media (min-width: 300px) and (max-width: 768px) {
    #intro {
        background-image: url('dimg/slider/275512923226868231659e9d0c3e-6195-48e6-b6db-10df006a6a3e.JPG');
        background-repeat: no-repeat;
        background-size: contain;
    }
}