:root {
    --background: rgba(255, 255, 255, 0.5);
    --background-img: url("background.jpg");
    --foreground: black;
}

html {
    background-image: var(--background-img);
    background-repeat: repeat;
    color: var(--foreground);
}

body {
    background-color: var(--background);
    padding: 2em;
}

@media (prefers-color-scheme: dark) {
    :root {
        --background: rgba(0, 0, 0, 0.5);
        --foreground: white;
        --background-img: linear-gradient(rgba(0, 0, 0, 0.4), rgba(0, 0, 0, 0.4)), url('background.jpg');
    }
}