How to Get As it is Certificate in C#

Hi,

This is My Aspx code and below is my c# code i am getting certificate but it comes with design issues. the images in certificate not coming in proper formats.

<asp:Panel ID="pnlCertificate" runat="server">
<div style="width: 1170px; padding-right:15px; padding-left:15px; margin-right:auto; margin-left:auto">
<div class="col-lg-12 margintop10" style="margin-top: 10px; width: 100%; height:auto">
<div class="col-lg-3" style="width: 25%">
div>
<div id="divPanel" runat="server" class="col-lg-5" style="font-family: Times New Roman;
font-style: italic; font-size: 17px; width: 41.66666667%;">
<%-- <div class="">--%>
<div class="bg-white margintop10 fulldiv" style="background-color: White; margin-top: 10px; width: 100%">
<div class="text-center" style="text-align: center;width: 100%; " >
<center>
<img src="http://tallyelearning.com/Student/Images/1.jpg" width="100%" alt="img" />
center>
div>
<div class="text-center" style="text-align: center;width: 100%">
This certificate is proudly presented to
div>
<div class="text-center margin-bottom10" style="text-align: center; margin-bottom: 10px;width: 100%">
<asp:Label ID="lblName" runat="server" Font-Bold="true" Font-Size="22px" CssClass="firebricktext text-capitalize" style="text-transform:capitalize; color:firebrick;">asp:Label>
div>
<div class="text-center margin-bottom10 margintop10" style="text-align: center; margin-bottom: 10px; margin-top:10px;width: 100%">
Successfully completed in<br />
<asp:Label ID="lblCourseName" CssClass="text-capitalize" runat="server" Font-Bold="true" style="text-transform:capitalize"
Font-Size="22px">asp:Label>
div>
<div class="text-center margintop10" style="text-align: center; margin-top: 10px; width: 100%">
<span>At Authorized training centerspan>
div>
<div class="text-center margin-bottom10" style="text-align: center; margin-bottom: 10px; width: 100%">
<asp:Label ID="lblTrainingCenter" CssClass="text-capitalize" style="text-transform:capitalize" runat="server" Font-Bold="true">asp:Label>
div>
<div class="text-center margin-bottom10 margintop10" style="text-align: center; margin-bottom: 10px; margin-top:10px;width: 100%">
<label>
He/She has awarded this certificate for distinctive<br />
performance in this programmelabel>
div>
<div style="margin-top: 30px; margin-bottom: -71px; float: left; width: 100%">
<div class="margin-bottom10 margintop10" style="margin-bottom: 10px; margin-top:10px;width: 100%">
<div class="col-lg-6" style="width:50%">
Grade :
<asp:Label ID="lblGrade" runat="server">asp:Label>
div>
<div class="col-lg-6 pull-right" style="width:50%; float:right">
Date of Issue :
<asp:Label ID="lblDateofIssue" runat="server">asp:Label>
div>
div>
<div class="margin-bottom10 margintop10 fulldiv pull-left" style="margin-bottom: 10px; margin-top:10px; width:100%; float:left">
<div class="col-lg-10" style="width: 83.33333333%">
Certificate No :
<asp:Label ID="lblCertificateNo" runat="server" Font-Size="18px">asp:Label>
div>
<div class="col-lg-1" style="width: 8.33333333%">
div>
div>
div>
<div class="text-center" style="text-align:center">
<img src="http://tallyelearning.com/Student/Images/21.jpg" width="100%" alt="img1" />
div>
div>
<%-- div>--%>
<%-- asp:Panel>--%>
div>
<div class="col-lg-4" style="width: 33.33333333%">
div>
<div class="col-lg-12 margintop10">
<div class="col-lg-2">
div>
<div class="col-lg-7 text-center">
<asp:LinkButton ID="lnkPrintPDF" OnClick="lnkPrintPDF_Click" runat="server" CssClass="btn btn-theme"
Visible="false"> Print PDF asp:LinkButton>
<%-- <asp:LinkButton ID="lnkPrintPDF" OnClick="lnkPrintPDF_Click" runat="server" CssClass="btn btn-theme"
Visible="false" OnClientClick="printDiv('divPanel')"> Print PDF asp:LinkButton>--%>
div>
<div class="col-lg-3">
div>
div>
div>
div>
asp:Panel>

public void DisplayCertificate()
{
int year = Convert.ToInt32(DateTime.Now.Year.ToString().Substring(2, 2));
int nextyear = year + 1;
string CertificateNo = "PMT" + "/" + 000 + "/" + year + "-" + nextyear;
lblName.Text = "Adhikar" + " " + "Patil";
lblCourseName.Text = "Tally.ERP 9 With GST";
lblTrainingCenter.Text = "Prompt Computer, Dhule";
lblDateofIssue.Text = System.DateTime.Now.ToString("dd/MM/yyyy");
lblCertificateNo.Text = CertificateNo;
lblGrade.Text = "A";
}
protected void lnkPrintPDF_Click(Object sender, EventArgs e)
{
//SendHTMLAttachment();
Response.ContentType = "application/pdf";
Response.AddHeader("content-disposition", "attachment;filename=TallyCertificate.pdf");
Response.Cache.SetCacheability(HttpCacheability.NoCache);
divPanel.Visible = true;
StringWriter stringWriter = new StringWriter();
HtmlTextWriter htmlTextWriter = new HtmlTextWriter(stringWriter);
divPanel.RenderControl(htmlTextWriter);
using (MemoryStream ms = new MemoryStream())
{
StringReader stringReader = new StringReader(stringWriter.ToString());
Document Doc = new Document(PageSize.A4, 25, 25, 30, 30);
//Document Doc = new Document(PageSize.A4, 10f, 10f, 100f, 0f);
HTMLWorker htmlparser = new HTMLWorker(Doc);
PdfWriter.GetInstance(Doc, Response.OutputStream);
Doc.Open();
htmlparser.Parse(stringReader);
Doc.Close();
Response.Write(Doc);
Response.OutputStream.Write(ms.GetBuffer(), 0, ms.GetBuffer().Length);
Response.End();
}