We will often provide CSS solutions to many of your questions.
Do not edit the style.css of the parent theme. The reason being that if you edit the parent theme then when you update the theme you will lose all of your changes.
You’re neither required to understand CSS or how to implement it via a child theme, if you don’t want to.
The Easy Way
When you’re supplied with CSS, you need only to simply copy and paste, from within your WP admin and theme options, here:
Appearance > Theme Options > Custom CSS Styles
And save. If you don’t see the changes, make sure to clear all caches.
The Recommended Way
For more advanced customizations, you will definitely want to look into child theming:
Want to Learn?
If you want to actually get hands-on and learn, we recommend using Firefox with Firebug.