by Davo Smith.
Although, unless you have a specific requirement that means you really have to load a separate stylesheet for the page, it is usually a better idea to create a file called 'styles.css' in the base folder of your plugin (e.g. blocks/myplugin/syles.css or mod/myplugin/styles.css ) and put your CSS definitions in there. That way it will be integrated into the single CSS file downloaded on all Moodle pages (avoiding the overhead of downloading a separate file).