JSFiddle - React, Tailwind, and code Playground

HTML

You will be auto logged out in <span id="SecondsUntilExpire"></span> seconds.

CSS

#SecondsUntilExpire { background-color: yellow; }

JavaScript

var IDLE_TIMEOUT = 60; //seconds
var _localStorageKey = 'global_countdown_last_reset_timestamp';
var _idleSecondsTimer = null;
var _lastResetTimeStamp = (new Date()).getTime();
var _localStorage = null;

AttachEvent(document, 'click', ResetTime);
AttachEvent(document, 'mousemove', ResetTime);
AttachEvent(document, 'keypress', ResetTime);
AttachEvent(window, 'load', ResetTime);

try {
    _localStorage = window.localStorage;
}
catch (ex) {
}

_idleSecondsTimer = window.setInterval(CheckIdleTime, 1000);

function GetLastResetTimeStamp() {
    var lastResetTimeStamp = 0;
    if (_localStorage) {
        lastResetTimeStamp = parseInt(_localStorage[_localStorageKey], 10);
        if (isNaN(lastResetTimeStamp) || lastResetTimeStamp < 0)
            lastResetTimeStamp = (new Date()).getTime();
    } else {
        lastResetTimeStamp = _lastResetTimeStamp;
    }
       
    return lastResetTimeStamp;
}

function SetLastResetTimeStamp(timeStamp) {
    if (_localStorage) {
        _localStorage[_localStorageKey] = timeStamp;
    } else {
        _lastResetTimeStamp = timeStamp;
    }
}

function ResetTime() {
    SetLastResetTimeStamp((new Date()).getTime());
}

function AttachEvent(element, eventName, eventHandler) {
    if (element.addEventListener) {
        element.addEventListener(eventName, eventHandler, false);
        return true;
    } else if (element.attachEvent) {
        element.attachEvent('on' + eventName, eventHandler);
        return true;
    } else {
        //nothing to do, browser too old or non standard anyway
        return false;
    }
}

function WriteProgress(msg) {
    var oPanel = document.getElementById("SecondsUntilExpire");
    if (oPanel)
         oPanel.innerHTML = msg;
    else if (console)
        console.log(msg);
}

function CheckIdleTime() {
    var currentTimeStamp = (new Date()).getTime();
    var lastResetTimeStamp = GetLastResetTimeStamp();
    var secondsDiff = Math.floor((currentTimeStamp - lastResetTimeStamp) / 1000);
    if...