How to add custom CSS to each page
An easier way to address multiple CSS loads, is to cache and compress the CSS. You can do so by going to /admin/config/development/performance and selecting "Aggregate and compress CSS files"

But if you must have them load on separate pages I'd recommend doing it the Drupal way; separating them by content types or blocks, forms, not by URI. The simplest way to do it, is to use Theme Hooks.

For instance, to include a yourthemedirecotry/css/MYTYPE.css for content type MYTYPE;


Copy /modules/node/node.tpl.php into your theme directory and rename it to node--mytype.tpl.php.
Insert &lt;?php drupal_add_css(path_to_theme() . '/css/mytype.css', array ('group' =&gt; CSS_THEME)); ?&gt;
Don't forget to flush cache.


From now on, nodes with content type MYTYPE will include a yourtheme/css/mytype.css.

Likewise, you can insert CSS into specific blocks, fields, page. For more options, see Theme Hooks and drupal_add_css.