This plugin can help a lot in theme customization, it will add CSS code into head section of your website but will only work for the pages/posts/widget which you will choose.
For complete demo visit http://websensepro.com/custom-css-for-pages-posts-widgets
安装:
If you use FTP to upload your plugins, unzip the zip file and upload the resulting directoy to /wp-content/plugins/
If you use the automatic uploader, there's no need to unzip the file first.
Activate the plugin through the 'Plugins' menu in WordPress
You will now see a new metabox on all edit screens for posts/pages/widgets.