nonCirLoad

gistfile1.txt

var nonCriLoad = function nonCriLoad() {

    var rps = document.getElementById('non-critical-css');
    if (!(rps.relList && rps.relList.supports && rps.relList.supports("preload"))) {
        rps.onload = "";
        //rps.rel="stylesheet";
        var ncs = document.createElement("link");
        ncs.rel = "stylesheet";
        ncs.href = rps.href;
        rps.appendChild(ncs);
        ["scroll"].forEach(function (e) {
            window.removeEventListener(e, nonCriLoad);
        });
    }
};
["scroll"].forEach(function (e) {
    window.addEventListener(e, nonCriLoad, { once: true, passive: true });
});