.contain {
}

    .contain:before {
        background: url("../dist/img/background.jpg") no-repeat center center fixed;
        -webkit-background-size: cover;
        -moz-background-size: cover;
        background-size: cover;
        -o-background-size: cover;
        content: '';
        display: block;
        position: fixed;
        left: 0;
        right: 0;
        top: 0;
        bottom: 0;
        opacity: 0.2;
        z-index: -10;
    }