We use the pseudo attributes ::-webkit-scrollbar to stylize the scroll bar and found that this gives an invalid argument in the call to document.querySelectorAll(rule.selector).
We modified the function indexRules so that when the selector is extracted we remove all colons.
var selector = (parsedRule[0].trim()).replace(/:/g,'');
We use the pseudo attributes ::-webkit-scrollbar to stylize the scroll bar and found that this gives an invalid argument in the call to document.querySelectorAll(rule.selector).
We modified the function indexRules so that when the selector is extracted we remove all colons.
var selector = (parsedRule[0].trim()).replace(/:/g,'');
Not sure if this has any side effects.