Not including styles in the global files has both advantages and disadvantages. The technique is a powerful approach from a maintenance and distributed-team standpoint, where multiple teams may need to import CSS files that are from a parent brand or some similar scenario. Additionally, from a CMS or template-based site structure, this has the added benefit of being able to add new CSS files without updating the XHTML site templates, because only a change to the CSS link files is required. Also, from a performance standpoint, if the forms rules are large in size, users do not need to download that data before it’s needed.
However, this performance consideration should be carefully considered, because there are also performance downsides. Essentially, for a given page a Web browser and a server are going to have to create and execute lots of HTTP requests.
To load a single page with the second example above, four HTTP requests are issued—which puts added burdens on both the client Web browser and the Web server. Multiply that by the full number of users hitting a site at a given moment and the number grows exponentially. This is one demonstration of how the CSS setup alone can impact page load times and site performance. The pros and cons of this type of approach should be carefully considered before being implemented.