Detect Browser : If you want to use a different stylesheet for different browsers you can use HTML conditional tags or you can use this.

functions.php

/** Detect Browser : If you want to use a different stylesheet for different browsers you can use HTML conditional tags or you can use this.
*
* https://www.nuno-sarmento.com
*/

add_filter('body_class','ns_browser_body_class'); 
function ns_browser_body_class($classes) { 
 
  global $is_lynx, $is_gecko, $is_IE, $is_opera, $is_NS4, $is_safari, $is_chrome, $is_iphone; 
 
  if($is_lynx) $classes[] = 'lynx'; 
 
  elseif($is_gecko) $classes[] = 'gecko'; 
 
  elseif($is_opera) $classes[] = 'opera'; 
 
  elseif($is_NS4) $classes[] = 'ns4'; 
 
  elseif($is_safari) $classes[] = 'safari'; 
 
  elseif($is_chrome) $classes[] = 'chrome'; 
 
  elseif($is_IE) $classes[] = 'ie'; 
 
  else $classes[] = 'unknown'; 
 
  if($is_iphone) $classes[] = 'iphone'; 
 
  return $classes; 

}