JSFiddle - React, Tailwind, and code Playground

HTML

<span class="ms-cui-row" 
    id="Ribbon.EditingTools.CPEditTab.Font-Medium-0-0">...</span>

JavaScript

var sel = [
    ".ms-cui-row",
    "#Ribbon.EditingTools.CPEditTab.Font-Medium-0-0",
    "[id=\"Ribbon.EditingTools.CPEditTab.Font-Medium-0-0\"]"
];

$.each(sel, function(i,s){
    document.write(s+": <b>"+$(s).length+"</b><br>");
});