dompdf and css

[eluser]canicasio[/eluser]
Hello

Im having problems with dompdf and css. Here is my code:

Code:

function pdf(){
        $this->load->helper('file');
        $this->load->plugin('to_pdf');
        $this->load->model('usuarios');
        $data['estilo']= base_url().'/CSS/impresion.css';
        $data['etiqueta']="Informacion de Analisis";
        $data['imagen']= base_url().'/imagenes/tubos.jpg';
        $this->load->view('impresion', $data);
        $html = $this->load->view('impresion', $data, true);
        pdf_create($html, 'prueba');    
    }

the pdf document does not present the style. Can someone help me?