As part of an effort to optimize your site and reduce page load time, you can reduce the number
of separate CSS files by merging them into a single condensed file. If you open a merged
CSS file, you’ll find one continuous stream of text, with line breaks removed. Because you can’t
edit the merged file, it’s best to wait until you are out of the development mode, and no longer
making frequent changes to the CSS.
To merge CSS files:
1. On the Admin menu, select System > Configuration. Then in the panel on the left under
Advanced, select Developer.
2. Click to expand the CSS Settings section
3. Set Merge CSS Files to “Yes.”
4. When complete, click the Save Config button.