Having multiple CSS files in WordPress can slow down your website due to the increased number of requests to the server.
To combine CSS files, create a new master CSS file, copy the contents of existing files, update WordPress to use the new file, and consider minifying the CSS for improved loading times.
The same principles apply to combining JavaScript files in WordPress. Create a new master JavaScript file, combine the scripts, update WordPress to load the new file, and test functionality post-merge.
Optimizing your site further can be done by using caching plugins, CDNs, and ensuring CSS specificity and script dependencies are maintained. Combining CSS and JavaScript files can enhance website speed and SEO ranking.