"SlickMap CSS is a simple stylesheet for displaying finished sitemaps directly from HTML unordered list navigation. It's suitable for most web sites - accommodating up to three levels of page navigation and additional utility links - and can easily be customized to meet your own individual needs, branding, or style preferences."
Modernizr doesn't actually magically enable CSS3 properties for browsers that don't support them. It just tells the page whether that feature is supported on the browser the visitor is using or not.