Set Default Font Style and Size for TextBox and DropDownList throughout application in ASP.Net

1. Add a CSS File to your project say CSS.css

2. Place the following CSS in it

input[type=text]
{
    font-family:Arial;
    font-size:11pt;
}
select
{
    font-family:Arial;
    font-size:16pt;
}

3. Inherit it in Head Section of MasterPage or Page.

<link href="ss.css" rel="stylesheet" type="text/css" />