itextsharp不在乎我的html样式

我在页面中创建一个面板，并在页面中动态创建div和表。当我用itextsharp转换为pdf时，它不在乎我的div或表样式，它会让我看起来很糟糕。我该怎么解决这个问题。这是我转换html的代码。

String HTML = Session["xpdf"].ToString();
string filename = "''xpdf''xpdf____" + Request.QueryString["id"] + ".pdf";
string filepath = HttpContext.Current.Server.MapPath("''xpdf''xpdf____" + Request.QueryString["id"] + ".pdf");
Document document = new Document(PageSize.A4);
PdfWriter.GetInstance(document, new FileStream(filepath, FileMode.Create));
document.Open();
HTMLWorker hw = new HTMLWorker(document);
hw.Parse(new StringReader(HTML));
document.Close();
ShowPdf(filename, filepath);
PdfAction action = new PdfAction(PdfAction.PRINTDIALOG);

考虑一下我的html代码是这样的：

<div>
   <table style="border:solid 1px #ccc; color:#000;">
      <tr>
          <td style="width:100px;color:#cc0000;"></td>
          <td style="width:10px">:</td>
          <td style="width:200px"></td>
      </tr>
   </table>
</div>

Document document = new Document(PageSize.A4);
PdfWriter writer = PdfWriter.GetInstance(document, new FileStream(filepath, FileMode.Create));
document.Open();
HTMLWorker hw = new HTMLWorker(document);
StringReader sr = new StringReader(HTML);
XMLWorkerHelper.GetInstance().ParseXHtml(writer, document, sr);
//hw.Parse(new StringReader(HTML));
document.Close();
ShowPdf(filename, filepath);
PdfAction action = new PdfAction(PdfAction.PRINTDIALOG);