JSFiddle - React, Tailwind, and code Playground

by Vitaliy

HTML

<button id="ua">Click</button>

CSS

#ua{
  display:block;
  line-height:50px;
  background-image:linear-gradient(0deg, #00f, #0f0);
  width:100%;
  border:1px solid #ccc;
  border-radius:6px;
  cursor:pointer;
}

JavaScript

document.getElementById("ua").onclick = function(){
	var userAgent = navigator.userAgent;
  if(userAgent.indexOf("OPR") + 1){
  	this.style.background = "green";
    alert("Opera");
    return false;
  }
  if(userAgent.indexOf("Chrome") + 1){
  	this.style.background = "blue";
    alert("Chrome");
    return false;
  }
  if(userAgent.indexOf("Firefox") + 1){
  	this.style.background = "red";
    alert("Firefox");
    return false;
  }
}