server.js

const http = require('http');
const fs = require('fs');
const url = require('url');
const path = require('path');

const PORT = process.env.PORT || 3000;
const PUBLIC_DIR = path.join(__dirname, './');

const server = http.createServer((req, res) => {
    let filePath = path.join(PUBLIC_DIR, req.url === '/' ? 'index.html' : req.url);
    let extname = path.extname(filePath);
    let contentType = 'text/html';

    switch (extname) {
        case '.js':
            contentType = 'text/javascript';
            break;
        case '.css':
            contentType = 'text/css';
            break;
        case '.json':
            contentType = 'application/json';
            break;
        case '.png':
            contentType = 'image/png';
            break;
        case '.jpg':
            contentType = 'image/jpg';
            break;
        case '.svg':
            contentType = 'image/svg+xml';
            break;
    }

    let favicon = path.join(PUBLIC_DIR, '_img', 'favicon.svg');
    let pathName = url.parse(req.url).pathname;

    if (req.method === 'GET' && pathName === '/favicon.ico') {
        res.setHeader('Content-Type', 'image/svg+xml');
        fs.createReadStream(favicon).pipe(res);
        return;
    }

    fs.readFile(filePath, (err, data) => {
        if (err) {
            if (err.code === 'ENOENT') {
                fs.readFile(path.join(PUBLIC_DIR, '404.html'), (err, data) => {
                    res.writeHead(404, { 'Content-Type': 'text/html' });
                    res.end(data, 'utf8');
                });
            } else {
                res.writeHead(500);
                res.end(`Server Error: ${err.code}`);
            }
        } else {
            res.writeHead(200, { 'Content-Type': contentType });
            res.end(data, 'utf8');
        }
    });
});

server.listen(PORT, () => {
    console.log(`Server running on http://localhost:${PORT}`);
});