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.

vgstef

Sometimes, we just want to offer visitors simple variations of our website theme. Sometimes, we simply want to offer a stylesheet with improved accessbility. There are plugins that let you choose a different theme, but this plugin offers you to change only the stylesheet. In the admin settings, you can configure as many different stylesheets as you want. Those possibilities are offered in a list on the front page.
The list of available stylesheets can be shown in a dropdown list or as a series of icons. It can be shown using the widget or in a page/post using the shortcode, or directly in the template using the php function.
On the frontend, when a choice is made in the dropdown list, the webpage is reloaded using the chosen stylesheet.
<h4>Plugin Features</h4>
<ul>
<li>Easy installation/setup</li>
<li>Any number of switchers</li>
<li>Each switcher can have any number of stylesheet options</li>
<li>Set a default stylesheet</li>
<li>Multiple instances of switchers/stylesheet lists can be present on the same page.</li>
<li>Choice between a dropdown or icon list for each list</li>
<li>Can be used with a shortcode in a post/page, with the widget and with a php function in the theme</li>
<li>For each list, possibility to show/hide the title</li>
<li>Optional single switcher button (text or icon)</li>
<li>Chose between theme relative path or absolute path (useful to customize multisite)</li>
<li>Optional automatic theme rotation (weekday, week, month, year or random)</li>
<li>Ready for internationalization</li>
<li>Complete uninstall (removes options and widgets)</li>
</ul>
<h4>Languages already available</h4>
<ul>
<li>English</li>
<li>French</li>
<li>Spanish (thanks to Andrew Kurtis from WebHostingHub)</li>
<li>Serbo-Croatian (thanks to Andrijana Nikolic from WebHostingGeeks)</li>
</ul>
To see an example, visit <a href="http://web.globulesverts.org/wp-user-stylesheet-switcher" rel="nofollow ugc">plugin page</a>.

WP User Stylesheet Switcher

I'm using this on a site I'm developing that will have a "feminine style" and a "masculine style".  The site is in development so I didn't want to replace the default style.css as that would mean updating two stylesheets (ugh!).  Because the style switcher is loaded in the header after the main stylesheet, this is  what I did to cut down work ...

In the plugin I identified the default stylesheet as "Feminine Style" and entered a fake stylesheet name so it would never get replaced.  I then created a real "Masculine Style" and entered it's correct stylesheet name.  

This way the masculine overrides just the feminine styles I add to it to change :D  It works great.

Works Great

Adds a list (or multiple list) of stylesheets in the frontend to allow visitors to choose a different visual look for the website.

WP Add Custom CSS vs WP User Stylesheet Switcher