//just a quick function for copy/pasting into the console
function xpath(path, root) { return document.evaluate(path, root || document, null, XPathResult.FIRST_ORDERED_NODE_TYPE, null).singleNodeValue; }

//more js-styled functions
function getElementsByXPath(xpath, parent) {
    let results = [];
    let query = document.evaluate(xpath, parent || document,
        null, XPathResult.ORDERED_NODE_SNAPSHOT_TYPE, null);
    for (let i = 0, length = query.snapshotLength; i < length; ++i) {
        results.push(query.snapshotItem(i));
    }
    return results;
}

function getElementByXPath(path, root) {
    return document.evaluate(path, root || document, null, XPathResult.FIRST_ORDERED_NODE_TYPE, null).singleNodeValue;
}

function shadowCss(query, target) {
    function findRoots(ele) {
       return [ele, ...ele.querySelectorAll('*')]
           .filter(e => !!e.shadowRoot)
           .flatMap(e => [e.shadowRoot, ...findRoots(e.shadowRoot)])
    }
    return findRoots(target || document.body)
       .map(sr => sr.querySelector(query))
       .filter(el => el != null)[0];
}