To change the Title or Cascading Style Sheet rules in a Master Page, you can use the Page.Header property.
File: Default.master
<%@ Master Language="C#" %>
"http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">
Simple Master
File: Default.aspx
<%@ Page Language="C#" MasterPageFile="~/Default.master" %>
ID="Content1"
ContentPlaceHolderID="ContentPlaceHolder1"
Runat="Server">
Content in the first column
Content in the first column
ID="Content2"
ContentPlaceHolderID="ContentPlaceHolder2"
Runat="Server">
Content in the second column
Content in the second column