body {
    position: relative;
    min-height: 100vh;
}

body::before {
    content: '';

    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-image: url('../images/background_illustration.webp');
    background-repeat: no-repeat;
    background-attachment: fixed;
    background-size: cover;
    opacity: 0.4;
    z-index: -1;
}