JSFiddle - React, Tailwind, and code Playground

HTML

<div class="test">text</div>

CSS

.test {color: red}

.ie11 .test {color: green}

JavaScript

navigator.sayswho= (function(){
    var ua=  navigator.userAgent, tem, 
    M= ua.match(/(opera|chrome|safari|firefox|msie|trident(?=\/))\/?\s*([\d\.]+)/i) || [];
    if(/trident/i.test(M[1])){
        tem=  /\brv[ :]+(\d+(\.\d+)?)/g.exec(ua) || [];
        return 'IE '+(tem[1] || '');
    }
    M= M[2]? [M[1], M[2]]:[navigator.appName, navigator.appVersion, '-?'];
    if((tem= ua.match(/version\/([\.\d]+)/i))!= null) M[2]= tem[1];
    return M.join(' ');
})();


if(navigator.sayswho == 'IE 11.0') {
    document.querySelector('body').className += ' ie11';
}