qstudio

Easily include browser specific stylesheets in templates or select browser and version specific classes in CSS.
Conditional browser stylesheets are added after the main theme style.css allowing them to overrule previous rules – you only need to add the CSS rules that should change.
This plugin uses up-to-date WordPress top level functions, sanitizes all input data and is fully internationalized.
For feature request and bug reports, <a href="https://qstudio.us/support/categories/conditional-stylesheets-and-body-classes" rel="nofollow ugc">please use the Q Support Website</a>.
Please do not use the WordPress.org forum to report bugs, as we no longer monitor or respond to questions there.
<h4>Features</h4>
<ul>
<li>Checks for and adds browser and version specific stylesheets – such as “browsers-windows-firefox.css”.</li>
<li>Add browser and version specific body classes to all pages – such as body.browsers-msie-10</li>
<li>Includes the Mobile Detect class and adds mobile & touch body classes.</li>
<li>Adds a post type body class, for example: “posttype-page”.</li>
<li>Inserts handy HTML comments in the HTML footer of template files to tell you which CSS files could be used and which were found.</li>
</ul>

Conditional Stylesheets and Body Classes

Add conditional browser stylesheets and body class declarations

jshoptaw

This plugin allows you to use uploaded CSS files that can be used across themes without having to edit any theme files or use FTP.
For example, if you wanted to use Font Awesome on your site but your current theme doesn’t include it (or you know you want to use Font Awesome regardless of what theme you’re using), you can simply upload the <code>font-awesome.css</code> (or <code>font-awesome.min.css</code>) file using the WordPress Media Uploader then activate said stylesheet in the Theme-Independent Stylesheets (TISS) settings. That CSS file will then automatically be included on your site no matter what theme you’re using. Even if you switch themes, the CSS file will still be called in your site’s <code><head></code> (as long as the theme is coded to properly use <code>wp_head()</code>, which most themes are).

Theme-Independent Stylesheets

Allows for use of uploaded stylesheets (.css files) to be used alongside any theme

Conditional Stylesheets and Body Classes vs Theme-Independent Stylesheets