Codeigniter - pdf generated using dompdf is not as per the html format

Question

Seems like a similar question has been asked before but none solves the issue that I am facing.

I have a view called job_invoice which is loading properly in browser in html format. In that html page, there is a button called Send invoice, when you click on that button, it calls the below function sitting in controller file (through the routes.php). Then a pdf file is being generated and emailed to the email address but in very distored format. Looks like css is not loading properly.

public function send_invoice_email($id)
    {
        $data[ 'id' ] = $id;
        $data[ 'model_obj' ] = $this->User_model;
        $html =   $this->load->view( 'adminpages/print_invoice', $data , true);

        $this->load->library('pdf');
        
        $pdf = new Dompdf\Dompdf(array('enable_remote' => true));
        $pdf->load_html($html);
        $pdf->render();
        $output = $pdf->output();-
        $pdfFilePath = FCPATH . "invoices/invoice" . $id . ".pdf";
        
        file_put_contents($pdfFilePath, $output);
        
        $this->load->library('email');
        $job =   $this->User_model->getdata(array('id'=>$id),'jobs')->row_array();

        $emailbody = "Hi <br><br>Please see attached the invoice";
        $this->email->set_newline("\r\n");
        $this->email->from('admin@gmail.com', 'Admin');
        $this->email->to($job['user_email']);
        $this->email->subject('Invoice');
        $this->email->message($emailbody);
        $this->email->attach($pdfFilePath);
        $this->email->send();
        $this->email->clear($pdfFilePath);

        $this->session->set_flashdata( 'success', 'Invoice Email send successfully' );
        unlink($pdfFilePath);
        redirect(base_url('invoice/').$id);
    }

dompdf library structure is ../application/libraries/vendor/dompdf/dompdf

In the library folder, there is Pdf.pdf file as well

with this code

<?php defined('BASEPATH') OR exit('No direct script access allowed');
/**
 * CodeIgniter PDF Library
 *
 * Generate PDF's in your CodeIgniter applications.
 *
 * @package         CodeIgniter
 * @subpackage      Libraries
 * @category        Libraries
 * @author          Chris Harvey
 * @license         MIT License
 * @link            https://github.com/chrisnharvey/CodeIgniter-PDF-Generator-Library
 */

require_once(dirname(__FILE__) . '/vendor/autoload.php');
use Dompdf\Dompdf;

class Pdf extends Dompdf
{
    /**
     * Get an instance of CodeIgniter
     *
     * @access  protected
     * @return  void
     */
    protected function ci()
    {
        return get_instance();
    }

    /**
     * Load a CodeIgniter view into domPDF
     *
     * @access  public
     * @param   string  $view The view to load
     * @param   array   $data The view data
     * @return  void
     */
    public function load_view($view, $data = array())
    {
        $html = $this->ci()->load->view($view, $data, TRUE);

        $this->load_html($html);
    }
}