Liz,
Just realized that the snippet is stripping out styles. Here's how you can get the same result -
Add your style block in the custom HTML HEAD section of the "Edit Page meta tags" dialog as shown below -

Create snippet without style as shown below -

Place the snippet on the Landing Page (LP) and you will see the styles. Here's my example LP with your style http://na-qe.marketo.com/lp/socialoct/raj_regression_LPWithSnippetStyle.html