MediaWiki:Gadget-dark-mode-loader.js

(function() {
    var DARK_COOKIE = 'darkmode',
        THEME_COOKIE = 'theme',
        isUsingDarkmode = mw.cookie.get(THEME_COOKIE) === 'dark' ||
                          (!mw.cookie.get(THEME_COOKIE) && mw.cookie.get(DARK_COOKIE) === 'true');
    
    if (isUsingDarkmode) {
        document.documentElement.classList.add('wgl-theme-dark', 'wgl-darkmode');
        document.documentElement.classList.remove('wgl-theme-light', 'wgl-lightmode');
    } else {
        document.documentElement.classList.add('wgl-theme-light', 'wgl-lightmode');
        document.documentElement.classList.remove('wgl-theme-dark', 'wgl-darkmode');
    }
})();