Andrei Lupu

You can use this plugin to add a unique CSS class to your pages or posts.
<h4>Demo</h4>
<a href="https://tastewp.com/" rel="nofollow ugc">TasteWP</a> has prepared a quick WordPress instance with this plugin, so you can give it a try <a href="https://demo.tastewp.com/wp-custom-body-class" rel="nofollow ugc">in this demo</a>
<h4>Responsiveness</h4>
There’s a way to add a class to appear only on mobile devices. You can do that by simply adding <code>mobile-</code> on the front of 
the class. For example, if you want to have the class “car” for mobile side, you need to use “mobile-car”.
<h4>Support me</h4>
If you find this plugin helpful, or you just want to send me a coffee here are the ways:
<ul>
<li>Use the Github Sponsor button</li>
<li><a href="https://ko-fi.com/thelup" rel="nofollow ugc">Ko-fi</a></li>
<li>Watch me coding on <a href="https://www.twitch.tv/thelup/" rel="nofollow ugc">twitch.tv/thelup</a></li>
<li>Or simply visit my site <a href="https://a.lup.dev/" rel="nofollow ugc">lup.dev</a> and make those analytics ring the bells.</li>
</ul>

Custom Body Class

A plain simple plugin which allows you to add a custom CSS class the HTML body tag.

Aaron T. Grogg

This plug-in takes the URL, chops it into pieces, and adds each “piece” as an additional 
class to the <code>body</code> tag.
Meaning, if your page’s URL is: 
http://www.example.com/2012/02/24/wordpress-plugin-add-url-slugs-as-body-classes/ 
Your page’s <code>body</code> tag would have at least these classes: 
 2012 02 24 wordpress-plugin-add-url-slugs-as-body-classess
It gets much stronger when you start thinking about Categories or nested Pages: 
 http://www.example.com/category/wordpress/ 
which would add: 
 category wordpress 
while: 
 http://www.example.com/movies/star-trek/wrath-of-khan/ 
would add: 
 movies star-trek wrath-of-khan
This allows you to very easily add custom CSS and/or JS to these pages based on these new CSS classes.
Please let me know if you have any questions/suggestions/thoughts, 
Atg 
http://aarontgrogg.com/ 
aarontgrogg@gmail.com

Custom Body Class vs Add URL Slugs as Body Classes