body {
    background-color: transparent;
    background-image: url("../images/2a.jpg");
    background-repeat: no-repeat;
    background-position: center top;
    background-attachment: fixed;
    background-size: 100%;
}

@media (min-width: 300px) {
    body {
        background-image: url("../images/2.jpg");
    }

    @media (min-width: 480px) {
        body {
            background-image: url("../images/2.jpg");
        }
    }

    @media (min-width: 768px) {
        body {
            background-image: url("../images/2.jpg");
        }
    }

    @media (min-width: 1200px) {
        body {
            background-image: url("../images/2a.jpg");

        }
    }
}