#resImage_603 {
    display:block;
    overflow:hidden;
    background-image:url('https://greatstbarts900.firthdesign.co.uk/assets/images/b/4-plans-a3dbd318.jpg');
    background-repeat:no-repeat;
    background-position:center center;
        width:100%;
    background-size: cover;
        height:300px;
}
@media screen and (min-width:700px){
    #resImage_603 {
        background-image:url('https://greatstbarts900.firthdesign.co.uk/assets/images/c/4-plans-522a64c3.jpg');
                height:400px;
    }
}
@media screen and (min-width:980px){
    #resImage_603 {
        background-image:url('https://greatstbarts900.firthdesign.co.uk/assets/images/f/4-plans-78abb63b.jpg');
                height:420px;
    }
}
@media screen and (min-width:1400px){
    #resImage_603 {
        background-image:url('https://greatstbarts900.firthdesign.co.uk/assets/images/d/4-plans-fcdc8a47.jpg');
                height:420px;
    }
}