Often you run into CSS issues with different browsers, and one way to easily make browser-specific CSS is if you have a browser class added to the body tag of your theme. That way you can for example just add .ie8 .myclass { cssfix } to specify CSS that will only be read by a certain browser (IE8 in this case).
function alx_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) { $browser = $_SERVER['HTTP_USER_AGENT']; $browser = substr( "$browser", 25, 8); if ($browser == "MSIE 7.0" ) { $classes[] = 'ie7'; $classes[] = 'ie'; } elseif ($browser == "MSIE 6.0" ) { $classes[] = 'ie6'; $classes[] = 'ie'; } elseif ($browser == "MSIE 8.0" ) { $classes[] = 'ie8'; $classes[] = 'ie'; } elseif ($browser == "MSIE 9.0" ) { $classes[] = 'ie9'; $classes[] = 'ie'; } else { $classes[] = 'ie'; } } else $classes[] = 'unknown'; if( $is_iphone ) $classes[] = 'iphone'; return $classes; } add_filter( 'body_class', 'alx_browser_body_class' );