how can I remove left and right margin from my default.aspx

how can I remove the left and right margin from my default.aspx. I have tried to change the bootstap.cs but in vain. I am using just a standard template from the visual studio webapplication having standard default.aspx. But the problem that lot of space is left on the right side for the menu and for the page as well. The picture shows the required result. Code is for site.master is below. I have just pasted but again it is standard in the visual studio. So the same reference can be taken.

<%@ Master Language="C#" AutoEventWireup="true" CodeBehind="Site.master.cs" Inherits="WebApplication1.SiteMaster" %>

<!DOCTYPE html>

<html lang="en">
<head runat="server">
    <meta charset="utf-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title><%: Page.Title %> - My ASP.NET Application</title>

    <asp:PlaceHolder runat="server">
        <%: Scripts.Render("~/bundles/modernizr") %>
    </asp:PlaceHolder>

    <webopt:bundlereference runat="server" path="~/Content/css" />
    <link href="~/favicon.ico" rel="shortcut icon" type="image/x-icon" />

</head>
<body>
    <form runat="server">
        <asp:ScriptManager runat="server">
            <Scripts>
                <%--To learn more about bundling scripts in ScriptManager see https://go.microsoft.com/fwlink/?LinkID=301884 --%>
                <%--Framework Scripts--%>
                <asp:ScriptReference Name="MsAjaxBundle" />
                <asp:ScriptReference Name="jquery" />
                <asp:ScriptReference Name="bootstrap" />
                <asp:ScriptReference Name="WebForms.js" Assembly="System.Web" Path="~/Scripts/WebForms/WebForms.js" />
                <asp:ScriptReference Name="WebUIValidation.js" Assembly="System.Web" Path="~/Scripts/WebForms/WebUIValidation.js" />
                <asp:ScriptReference Name="MenuStandards.js" Assembly="System.Web" Path="~/Scripts/WebForms/MenuStandards.js" />
                <asp:ScriptReference Name="GridView.js" Assembly="System.Web" Path="~/Scripts/WebForms/GridView.js" />
                <asp:ScriptReference Name="DetailsView.js" Assembly="System.Web" Path="~/Scripts/WebForms/DetailsView.js" />
                <asp:ScriptReference Name="TreeView.js" Assembly="System.Web" Path="~/Scripts/WebForms/TreeView.js" />
                <asp:ScriptReference Name="WebParts.js" Assembly="System.Web" Path="~/Scripts/WebForms/WebParts.js" />
                <asp:ScriptReference Name="Focus.js" Assembly="System.Web" Path="~/Scripts/WebForms/Focus.js" />
                <asp:ScriptReference Name="WebFormsBundle" />
                <%--Site Scripts--%>
            </Scripts>
        </asp:ScriptManager>

        <div class="navbar navbar-inverse navbar-fixed-top">
            <div class="container">
                <div class="navbar-header">
                    <button type="button" class="navbar-toggle" data-toggle="collapse" data-target=".navbar-collapse" title="more options">
                        <span class="icon-bar"></span>
                        <span class="icon-bar"></span>
                        <span class="icon-bar"></span>
                    </button>
                    <a class="navbar-brand" runat="server" href="~/">Application name</a>
                </div>
                <div class="navbar-collapse collapse">
                    <ul class="nav navbar-nav">
                        <li><a runat="server" href="~/">Home</a></li>
                        <li><a runat="server" href="~/About">About</a></li>
                        <li><a runat="server" href="~/Contact">Contact</a></li>
                        <li><a runat="server" href="~/Contact">Hello</a></li>
                    </ul>
                </div>
            </div>
        </div>
        <div class="container body-content">
            <asp:ContentPlaceHolder ID="MainContent" runat="server">
            </asp:ContentPlaceHolder>
            <hr />
            <footer>
                <p>&copy; <%: DateTime.Now.Year %> - My ASP.NET Application</p>
            </footer>
        </div>

Solution

You can just make a utility class or just directly add the following class to the elements.

Add this inside your Head tag

<style>
.rm-margin{
    margin-left: 0 !important;
    margin-right: 0 !important; 
}
</style>

!important would override any bootstrap stylings.

Add the rm-margin to the div you want

You can just change below lines

<div class="navbar navbar-inverse navbar-fixed-top rm-margin">

<div class="container body-content rm-margin ">