<a href="http://pjdietz.com/wordpress-plugins/custom-css-js/" rel="nofollow ugc">Custom CSS and JS</a> allows you to add stylesheets and JavaScripts to any individual post by adding custom fields. Both CSS and scripts can be either internal or external. Since this is a plugin, the custom CSS and JavaScript are available to any theme used to display the post, as long as the themes call “wp_head”.
<h3>Using the Plugin</h3>
To use the plugin, add any combination of the following custom fields to your post.
custom_css 
Add an external stylesheet by adding a custom field with the name custom_css. The value of the field should be the path to your css file.
cusrom_css_code 
Add an internal stylesheet by adding a custom field with the name custom_css_code. Include your CSS code as the value. (Do not include the style tags.)
custom_js 
Add an external JavaScript by adding a custom field with the name custom_js. The value of the field should be the path to your script.
custom_js_code 
Add an internal JavaScript by adding a custom field with the name custom_js_code. Include your JavaScript code as the value. (Do not include the script tags.)
<h3>Custom Fields Order</h3>
<ol>
<li>The external styles and scripts are included before the internal ones.</li>
<li>If you include multiple entries for a given field, the entries will be included in order.</li>
</ol>
<h3>Okay, but what if I don’t like those tags?</h3>
Just edit custom-css-js.php and change the constants defined near the top of the file.
<h3>Note</h3>
This plugin only works with individual posts and pages. It does not work for list pages (e.g., the index page, search results).

Custom CSS and JS

Custom CSS and JavaScript allows you to add custom internal and external CSS and JavaScripts to individual posts.

TylerShaw

What’s It Do?
This plugin adds a box to your pages and posts allowing for page-specific or post-specific CSS stylesheets.
Why Use It?
After developing quite a few WordPress websites, it seems to me that the style.css file gets bloated. If you add a style used on only one page, and then later that page is deleted, you’re visitors now have to download those styles that aren’t even used. It’s wasteful, but maintaining a clean style.css file requires an active effort. This plugin solves that by attaching the these styles to the page or post, allowing them to be updated just like the content is and deleted with the page.
It keeps your style.css file clean and reduces unused style clutter.
What About Efficiency?
There shouldn’t be an issue with overhead from the plugin. Admin code is only executed in the admin panel and front end code is executed on the front end. If you’re website has a large amount of page-specific styles within it that can be migrated into the plugin, it can boost performance by reducing the download size of your style.css file.
Roadmap
This plugin will receive ongoing maintenance as WordPress evolves. No major features are planned, but I am entirely open to feature requests!
Feel free to suggest any feature you desire, or check out the code or contribute on <a href="https://github.com/tyler-shaw/page-specific-stylesheets" rel="nofollow ugc">GitHub</a>, where the project is hosted.
<ul>
<li>Additional plugin options.</li>
</ul>
If you have a feature idea, suggest it.
Notes
<ul>
<li>Style data and options are not deleted by default on uninstall. You must check the options on the plugin settings page to enable the deletion of this data.</li>
</ul>

Page Specific Stylesheets

Adds a box allowing for the addition of page-specifc and post-specific CSS stylesheets. Reduces the need to edit and clutter up the style.css file.

Custom CSS and JS vs Page Specific Stylesheets