@media screen and (min-width:1440px) {
    .mainwth {
        width: 1100px;
    }
    .m-banner .bx-controls {
        width: 1050px;
    }
    .bck5main .m-banner .bx-controls {
        width: 500px;
    }
}
@media screen and (min-width:1600px) {
    .mainwth {
        width: 1280px;
    }
    .m-banner .bx-controls {
        width: 1200px;
    }
    .bck5main .m-banner .bx-controls {
        width: 580px;
    }
}
@media screen and (min-width:1920px) {
/*    .mainwth {
        width: 1500px;
    }
    .bck5main .bx-controls {
    width:728px;
    }*/
}