Barrett Golding

No more shoehorning stylesheets and JavaScripts into the post content box. No more loading scripts on every post that only a few use. Postscript lets you easily add libraries or single-post script and style files post-by-post.
The plugin uses the WordPress “enqueue” methods, which means you can control dependencies (when registering scripts), improve site performance by putting styles in the head and scripts in the footer, and eliminate loading multiple copies of the same library (jQuery, I’m looking at you).
<h4>Enqueue Registered Styles and Scripts (by Handle)</h4>
Use the Postscript meta box (Edit Post screen) to enqueue registered styles and scripts (listed by handle in checkboxes).
<h4>Enqueue Unregistered Styles, Scripts, and Data Files (by URL)</h4>
For each post, you can also enqueue unregistered files, by entering URLs in the meta box text fields for: 
* 1 CSS stylesheet. 
* 2 JavaScript URLs, e.g, one JSON data file and one script file.
<h4>Add Post and Body Classes</h4>
And for each post, you can add: 
* A classname, to the HTML body tag (requires <code>body_class()</code> in theme). 
* A classname, to <code>class="post"</code> list (inserted by WordPress, requires <code>post_class()</code> in theme).
<h4>Settings and Security</h4>
The Settings screen lets you control which user-roles and post-types display the Postscript meta box and which script/style handles users are allowed to enqueue.

Postscript

Data visionaries and multi-mediators, make any post sing with scripts and splendid with styles, all from within WordPress.

Daniele De Santis

WP Add Custom CSS allows you to add custom CSS to the whole website and to individual posts, pages and custom post types (such as Woocommerce products). 
The CSS rules applied to the whole website will override the default stylesheets of your theme and plugins, while the CSS rules applied to specific pages, posts or custom post types will override the main stylesheet too.
The plugin works with the most popular builders, such as Elementor, Gutenberg and the Classic Editor.
You can edit the main stylesheet from the the “Add custom CSS” settings page. 
The plugin also creates a new “Custom CSS” box in the editing area to add custom CSS to specific posts, pages and custom post types.
Select the preferred CSS output method from the plugin’s settings page to ensure seamless integration with caching and minification plugins or to improve above-the-fold rendering performance.

WP Add Custom CSS


Says it has not been tested against recent versions, but it works great still. Simple and elegant solution. Sep 13 2024


Still works great

Add custom css to the whole website and to specific posts and pages.

Postscript vs WP Add Custom CSS