TCPDF not render all CSS properties

I try to make a PDF writing CSS and HTML but my CSS doesn't appear in my PDF. The only thing considered is the font-size and font-color.

I give you the code (sorry, it's a little 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();