server.js

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

const server = http.createServer((req, res) => {
    let filePath = req.url === '/' ? '/preview.html' : req.url;
    filePath = path.join(__dirname, filePath);
    
    const ext = path.extname(filePath);
    const contentTypes = {
        '.html': 'text/html',
        '.css': 'text/css',
        '.js': 'text/javascript',
        '.json': 'application/json',
        '.go': 'text/plain'
    };
    
    fs.readFile(filePath, (err, data) => {
        if (err) {
            res.writeHead(404, {'Content-Type': 'text/plain'});
            res.end('Not Found: ' + req.url);
            return;
        }
        res.writeHead(200, {'Content-Type': contentTypes[ext] || 'text/plain'});
        res.end(data);
    });
});

const PORT = 80;
server.listen(PORT, () => {
    console.log(`Server running at http://localhost:${PORT}/`);
    console.log('Press Ctrl+C to stop');
});