JSFiddle - React, Tailwind, and code Playground

HTML

<!DOCTYPE HTML>
<html lang="en-US">
    <head>
        <meta charset="UTF-8">
        <title>Cтили</title>
    </head>
    <body>
        <div id="rules"></div>
    </body>
</html>

JavaScript

var elementList = new Array("B","I","U","HR"),
                index = elementList.length,
                rules = document.getElementById('rules');
                while(index--){
                    //создаем элемент
                    element = document.createElement(elementList[index]);
                    document.body.appendChild(element);
                    mstyle = element.style;

                    //заглавие
                    title = document.createElement("H1");
                    title.appendChild(document.createTextNode(elementList[index]));
                    rules.appendChild(title);

                    //табличка
                    table = document.createElement("TABLE");
                    rules.appendChild(table);
                    table.style.width="100%";
                    
                    for(var i in mstyle){
                        value = getStyle(element,i);
                        if(value!=null&&value!=""){
                            
                            tr = document.createElement("TR");
                            td1 = document.createElement("TD");
                            td2 = document.createElement("TD");
                            td1.appendChild(document.createTextNode(i));
                            td2.appendChild(document.createTextNode(value));
                            tr.appendChild(td1);
                            tr.appendChild(td2);
                            table.appendChild(tr);
                        }
                    }

                    element.parentNode.removeChild(element);
                }

            function getStyle(el,styleProp){
                var x = el;
                if (x.currentStyle)
                    var y = x.currentStyle[styleProp];
                else if (window.getComputedStyle)
                    var y = document.defaultView.getComputedStyle(x,null).getPropertyValue(styleProp);
                return y;
            }