body {
    position: relative;
    z-index: 0;
}

body:before {
    content: "";
    position: fixed;
    inset: 0;
    background-image: url("https://i.ibb.co/9mrZPmLj/IMG-3695.jpg");
    background-size: cover;
    background-position: center;
    background-attachment: fixed;
    filter: saturate(90%) brightness(95%);
    z-index: -1;
}