TCPDF ne rend pas toutes les propriétés CSS

j'essaie de faire un PDF en écrivant CSS et HTML mais mon CSS n'apparaît pas dans mon PDF. La seule chose considérée est la taille et la couleur de la police.

je vous donne le code (désolé, c'est un peu long...)

$config = sfTCPDFPluginConfigHandler::loadConfig('my_config');

    $doc_title    = "Fiche Logement";

    $html = <<<EOF
<style>
        .informations {
            padding: 10px;
            margin: 10px;
            border: 1px dotted black;}
        .informations table {
            margin-top: 10px;}
        #modif {
            margin: 20px;
            text-align: left;
            float: right;}
        #modif th {
            padding-left: 10px;}
        #modif td {
            padding-left: 10px;}
        #adresse {
            width: 307px;
            float: left;}
        #reservataire {
            width: 307px;
            float: right;}
        #intergen {
            width: 307px;
            float: right;}
        #infos {
            width: 290px;
            float: left;}
        #handicap {
            padding-bottom: 12px;
            width: 324px;
            float: right;}
        #charges {
            margin-bottom: 20px;
            width: 307px;
            float: left;}
        #loyer {
            width: 307px;
            float: right;}
        #commentaires {
            clear: both;}
        h2 {
            font-variant: small-caps;
            text-align: center;
            font-size: 19px;
            font-weight: bold;
            padding: 0px 0px 2px 5px;
            margin: 15px 0px 20px 0px;
            color: #000000;
            border-top: 1px dotted black;
            border-bottom: 1px dotted black;}

        h3 {
            width: 250px;
            font-variant: small-caps;
            font-size: 15px;
            font-weight: bold;
            padding: 0px 0px 0px 5px;
            margin: 0px;
            color: #225D6D;
            border-top: 1px dotted black;
            border-bottom: 1px dotted black;}
</style>


            <div id='intergen' class='informations'>
                <h3>Intergénérationnel</h3>
                <table>
                    <tr>
                        <th>Intergénérationnel :</th> <td><?php echo $logement->getIntergen() ?></td>
                    </tr>
                </table>
            </div>

            <div id='infos' class='informations'>
                <h3>Informations logement</h3>
                <table>
                    <tr>
                        <th>Bâtiment :</th> <td><?php echo $logement->Parclogement->getBatiment() ?></td>
                    </tr>
                    <tr>
                        <th>Taille :</th> <td><?php echo $logement->getTaille() ?></td>
                    </tr>
                    <tr>
                        <th>Type :</th> <td><?php echo $logement->getTypelog() ?></td>
                    </tr>
                    <tr>
                        <th>Surface habitable :</th> <td><?php if($logement->getSurfacehab() == 0){ echo 'Non Spécifié';} else {echo $logement->getSurfacehab(). " m²";} ?></td>
                    </tr>
                    <tr>
                        <th>Chauffage :</th> <td><?php echo $logement->getChauffage() ?></td>
                    </tr>
                    <tr>
                        <th>Ascenseur :</th> <td><?php echo $logement->getAscenseur() ?></td>
                    </tr>
                </table>
            </div>

            <div id='handicap' class='informations'>
                <h3>Infrastructures handicapés</h3>
                <table>
                    <tr>
                        <th>Immeuble accessible :</th> <td><?php echo $logement->getAccessibl() ?></td>
                    </tr>
                    <tr>
                        <th>Ascenceur accessible :</th> <td><?php echo $logement->getAscenseuracc() ?></td>
                    </tr>
                    <tr>
                        <th>Logement adaptable :</th> <td><?php echo $logement->getAdaptable() ?></td>
                    </tr>
                    <tr>
                        <th>Logement adapté :</th> <td><?php echo $logement->getAdapte() ?></td>
                    </tr>
                </table>
            </div>

EOF;

    //create new PDF document (document units are set by default to millimeters)
    $pdf = new sfTCPDF(PDF_PAGE_ORIENTATION, PDF_UNIT, PDF_PAGE_FORMAT, true);

    // set document information
    $pdf->SetCreator(PDF_CREATOR);
    $pdf->SetAuthor(PDF_AUTHOR);
    $pdf->SetTitle($doc_title);

    //set default header data
    $pdf->SetHeaderData(PDF_HEADER_LOGO, PDF_HEADER_LOGO_WIDTH, PDF_HEADER_TITLE, PDF_HEADER_STRING);

    //set margins
    $pdf->SetMargins(PDF_MARGIN_LEFT, PDF_MARGIN_TOP, PDF_MARGIN_RIGHT);
    $pdf->SetHeaderMargin(PDF_MARGIN_HEADER);
    $pdf->SetFooterMargin(PDF_MARGIN_FOOTER); 

    //set auto page breaks
    $pdf->SetAutoPageBreak(TRUE, PDF_MARGIN_BOTTOM);

    //set header and footer fonts
    $pdf->setHeaderFont(Array(PDF_FONT_NAME_MAIN, '', PDF_FONT_SIZE_MAIN));
    $pdf->setFooterFont(Array(PDF_FONT_NAME_DATA, '', PDF_FONT_SIZE_DATA));

    //set default monospaced font
    $pdf->SetDefaultMonospacedFont(PDF_FONT_MONOSPACED);

    // Fixe la taille de la page
    $pdf->SetDisplayMode(90);

    //initialize document
    $pdf->SetFont('helvetica', '', 10);
    $pdf->AddPage();

    // output some HTML code


    $pdf->writeHTML($html , true, false, true, false, '');

    //reset pointer to the last page
    $pdf->lastPage();  

    // Close and output PDF document
    $pdf->Output('fichelogement.pdf', 'I');

    // Stop symfony process
    throw new sfStopException();