This question may sound a bit weird/novice/stupid. Please bear with me.
The below code is a small portion of a webpage I have created using CSS, HTML and coldfusion.
HTML5 allows scoped stylesheets, but only Firefox supports it so far. There is also a polyfill JavaScript.
Therefore, you'll have to adapt your markup and styles so that it only matches part2, and not part1. In a pinch, you can precede every selector with #wrapper. For example, if a rule says a{color:red}, substitute that with #wrapper a {color:red;}.
By the way, part1 should probably be a child of instead of .