JSFiddle - React, Tailwind, and code Playground

HTML

<div id="a"></div>
<div id="b" style="padding:10px;"></div>

CSS

#a {padding:10px;}

JavaScript

//alert(document.getElementById('a').style.padding);
//alert(document.getElementById('b').style.padding);

 var stylePart = getStyle(document.getElementById("a"), "padding-right");
        alert(stylePart);

function getStyle(oElm, strCssRule) {
            var strValue = "";
            if (document.defaultView && document.defaultView.getComputedStyle) {
                strValue = document.defaultView.getComputedStyle(oElm, "").getPropertyValue(strCssRule);
            }
            else if (oElm.currentStyle) {
                strCssRule = strCssRule.replace(/\-(\w)/g, function (strMatch, p1) {
                    return p1.toUpperCase();
                });
                strValue = oElm.currentStyle[strCssRule];
            }
            return strValue;
        }