@media screen and (max-width: 1000px) {
    html, body { 
        overflow: hidden; 
        height: 100%;
    }

    body {
        margin: 0;
        padding: 0;
        background: #1b1d1f url("bg_2.jpg?v=1") repeat-x 50% 50% / contain;
        background-repeat: no-repeat;
    }
}

@media screen and (min-width: 1000px) {
    html, body { 
        overflow: hidden; 
        height: 100%;
    }

    body {
        margin: 0;
        padding: 0;
        background: #1b1d1f url("bg_1.jpg?v=1") repeat-x 50% 50% / contain;
        background-repeat: no-repeat;
    }
}