CSS Issues After Converting HTML Page to ASPX Page Options

[ftbadolato]

Hello, I purchased a template from TemplateMonster.com. I need to convert the pages to .aspx pages so I can code the business logic. Upon doing so, however, I immediately noticed some of the CSS is not working. I am terrible at CSS and don't know how to properly resolve the issue.

The original template page can be found here:
Original

The .aspx version of that same page is here:
ASPX Page

You can quickly see the differences. I believe the issue is occurring because there is a form element in the HTML and you can't have nested forms. All .aspx web form pages start with a form tag.

The tag in the template looks like:
<form class="rd-mailform form-modern form-darker form-disabled">

I tried simply converting that to:
<div class="rd-mailform form-modern form-darker form-disabled">

...but that did not work. Any help you can provide is greatly appreciated!