Styling and displaying fields in the editor

What are the styling options available if I wanted to reorganise sections of the new meta fields on the add/edit page?

For example I have two date pickers, “Date From” and “Date To”, and I’d like them to be side by side instead of beneath each other.

Can we do this via CSS? And if so which files would I need to edit?

Cheers,

Chris.

http://wordpress.org/plugins/simple-fields/