<p dir="auto">adding the col-lg-offset-2 or any other number doesn't work. upon searching i can't find any such class in the bootstrap.css file.</p>
<p dir="auto">To increase/decrease the size of form controls, you can add the classes input-lg or input-sm (at least according to the website [http://getbootstrap.com/css/#forms] - which is the most consistent solution). In the css code, however, the classes are called input-large and input-small.</p>