body {
    background-image: 
        linear-gradient(to top, rgba(0, 0, 0, 1), rgba(0, 0, 0, 0.55)),
        url("../images/background.png");
    width: 100%;
    min-height: 100vh;
    height: 100%;
    background-size: cover;
    background-repeat: no-repeat;
    background-attachment: fixed;
}