import cssVars from "css-vars-ponyfill"; cssVars({ // Targets rootElement : document, shadowDOM : false, // Sources include : 'link[rel=stylesheet],style', exclude : '', // Define CSS Variables and use them in CSS. variables : { }, // Options onlyLegacy : true, preserveStatic: true, preserveVars : false, silent : false, updateDOM : true, updateURLs : true, watch : false, // Callbacks onBeforeSend: function(xhr, elm, url) { // ... }, onError: function(message, elm, xhr, url) { // ... }, onWarning: function(message) { // ... }, onSuccess: function(cssText, elm, url) { // ... }, onComplete: function(cssText, styleElms, cssVariables, benchmark) { // ... }, onFinally: function(hasChanged, hasNativeSupport, benchmark) { // ... } });