I think Michal's answer is the best, but we can take it a step further and dynamically load an Android CSS as per the original question:
var isAndroid = /(android)/i.test(navigator.userAgent);
if (isAndroid) {
var css = document.createElement("link");
css.setAttribute("rel", "stylesheet");
css.setAttribute("type", "text/css");
css.setAttribute("href", "/css/android.css");
document.body.appendChild(css);
}