Using a child theme is the best and safest way to extend Customizr .
You can of course add functions and style in the original Customizr theme functions.php and style.css files, but they will be lost on upgrade. If you use a child theme, you are safe!
Find inspiration in the showcase
If you are new to WordPress and the Customizr theme, you might want to check those useful pages.
- Guide to customize the Customizr WordPress theme
- Customizr hooks API : extend the theme without limit
- Diagnosing problems in Customizr
- How to efficiently search a topic in the forum
- Inspect your webpages in your browser : the best spent 6 minutes!
- Guide to CSS and HTML in the Customizr WordPress theme
- Customizr Theme CSS Glossary
- Check out the code snippets section to find ready to paste extensions for your child theme.
Other resources on the web
- HTML Dog CSS Beginner tutorial
- W3 Schools CSS tutorial
- Web Design Group guide to CSS
- WestCiv complete CSS guide
- Sitepoint CSS articles
- Learn how to use the media queries
- CSS specifics for Internet Explorer