#home-back-1 {
    background: url('/images/commercial/photos/photo-home-1.png') no-repeat left top;
    -webkit-background-size: cover;
    -moz-background-size: cover;
    -o-background-size: cover;
    background-size: cover;
}
#home-back-2 {
    background: url('/images/commercial/photos/photo-home-2.png') no-repeat center top;
    -webkit-background-size: cover;
    -moz-background-size: cover;
    -o-background-size: cover;
    background-size: cover;
}

#about-back {
    background: url('/images/commercial/photos/photo-about-1.png') no-repeat center center fixed;
    -webkit-background-size: cover;
    -moz-background-size: cover;
    -o-background-size: cover;
    background-size: cover;
    height: 100vh;
}

#contact-back {
    background: url('/images/commercial/photos/photo-contact-1.png') no-repeat center center fixed;
    -webkit-background-size: cover;
    -moz-background-size: cover;
    -o-background-size: cover;
    background-size: cover;
}

#services-back {
    background: url('/images/commercial/photos/photo-services-1.png') no-repeat center center;
    -webkit-background-size: cover;
    -moz-background-size: cover;
    -o-background-size: cover;
    background-size: cover;
}

#resources-back-book-1 {
    background: url('/images/commercial/photos/photo-resources-book-1.jpg') no-repeat top center;
    -webkit-background-size: cover;
    -moz-background-size: cover;
    -o-background-size: cover;
    background-size: cover;
}

#resources-back-principles-1 {
    background: url('/images/commercial/photos/photo-principles-1.png') no-repeat top center;
    -webkit-background-size: cover;
    -moz-background-size: cover;
    -o-background-size: cover;
    background-size: cover;
}



.img800 {
    padding-top: 100px;
    height: 800px;
}

}
@media screen and (max-width: 1200px) {
    .img800 {
        padding-top: 100px;
        height: 700px;
    }
}

@media screen and (max-width: 991) {
    .img800 {
        padding-top: 80px;
        height: 600px;
    }
}

@media screen and (max-width: 769px) {
    .img800 {
        padding-top: 60px;
        height: 500px;
    }
}

@media screen and (max-width: 576px) {
    .img800 {
        padding-top: 40px;
        height: 400px;
    }
}