Adding Classes to Body

WordPress provides many body classes that allow you to narrow CSS to specific contexts. Examples:

• .post-type-archive-portfolio - Styling to the 'portfolio' post type archive.
• .archive - Styling for any archive page (post type archive, category, tag...)
• .single-portfolio - Styling for single posts in the 'portfolio' post type
• .single - Styling for any singular post

But sometimes you need to add your own class. The most common area where I add custom classes is when the same template file is used for multiple contexts .

You might have a 'portfolio' post type with a 'project-features' taxonomy. Both the post type archive and taxonomy term archive should use the same styling since they're both listing portfolio items. See the link above for how to make the taxonomy use this template file. In the template file itself I'd add the following so they all have the same class, .portfolio-archive:

You can place this in individual template files, or put it in functions.php to control body classes site-wide.