Node.js - Can't Get .CSS To Apply To My .HTML Locally

I have been trying to fix this for over 4 hours now, and I have read through all of the related questions/answers here on StackOverflow, as well as other websites. Right now I have a router and server that displays the correct .html according to what URL path I visit. However, no matter what I try to do to get the requested .css in the .html to apply, it does not work. When I try to go to the specified path, it doesn't load anymore. I have tried using path.extname(), switch statements and if/else statements to change the ContentType, and several other things.

Here is my code that displays .html fine. This is the code without any of my attempts to get .css / .js to run. Like I said earlier, I tried using path.extname() and other things.(Note - I've never posted here before so the code formatting isn't tabbed or indented like how I have it, I don't know how to do that here so I'm sorry about that):

Router.js

        var url = require('url'),
            fs = require('fs'),
            reqURL,
            pathname;

        var router = function(req, res) {

       reqURL = url.parse(req.url, true);
       pathname = reqURL.pathname;

       res.status = 200;
       res.contentType = 'text/plain';

       res.send = function(sentItem) {
       if (sentItem) {

      res.writeHead(res.status, {'Content-Type': res.contentType});
      res.write(sentItem);
      res.end();

    } else {
        throw new Error('No parameter passed to res.send()');

     }
    };

     res.render = function(filename) {   
       //My local folder that contains my .html and .css files
     var path = './views';  

      if (filename) {
      fs.readdir(path, function(error, files) {
        if (error) {
        throw error;

        } else {
        if (files.indexOf(filename) !== -1) {
        var file = files[files.indexOf(filename)];
         fs.readFile(path + '/' + file, function(error, data) {

              if (error) {
         throw error;

              } else {
         res.writeHead(res.status, {'Content-Type': 'text/html'});
                res.write(data);
                res.end();

              }

            });

          } else {
         throw new Error("res.render() could not find the specified file.");
          }

        }

      });

    } else {
       throw new Error('No parameter passed to res.render()');

    }
      };
        if (pathname === '/') {
    res.send("Welcome to the home page.");
       }

       if (pathname === '/test') {
    res.render('website7.html');
       }
         else if (pathname === '/alex') {
    res.render('alex.html');
    }
      else {
      res.status = 404;
       res.send("Sorry, but I could not find that!");
    }
    }
       //Exporting custom module to be used in app.js
        module.exports = router

App.js

var http = require('http');
    var router = require('./router');

    var server = http.createServer(function(req, res) {
    router(req, res);
    });

   server.listen(5000, function() {
   console.log('Listening on http://localhost:5000');
   });