Websites/webkit.org/demos/dialog-element/dark-theme.css

body {
    color-scheme: light dark;
}

@media (prefers-color-scheme: dark) {
    body {
        background-color: #000;
        color: #fff;
    }
    dialog {
        background-color: #313231;
        color: #d7d7d8;
    }
}