body {
    background: #363534;
    background-image: url("../images-new/misc/DJI_0248.jpg");
    background-size: cover;
    background-attachment: fixed;
}

    body:before {
        content: '';
        position: fixed;
        top: 0;
        bottom: 0;
        left: 0;
        right: 0;
        background-color: rgba(0,0,0,0.3);
    }