Target ALL VERSIONS of IE
<!--[if IE]>
<link rel="stylesheet" type="text/css" href="all-ie-only.css" />
<![endif]-->
Target everything EXCEPT IE
<!--[if !IE]><!-->
<link rel="stylesheet" type="text/css" href="not-ie.css" />
<!--<![endif]-->
Target IE 7 ONLY
<!--[if IE 7]>
<link rel="stylesheet" type="text/css" href="ie7.css">
<![endif]-->
Target IE 6 ONLY
<!--[if IE 6]>
<link rel="stylesheet" type="text/css" href="ie6.css" />
<![endif]-->
Target IE 5 ONLY
<!--[if IE 5]>
<link rel="stylesheet" type="text/css" href="ie5.css" />
<![endif]-->
Target IE 5.5 ONLY
<!--[if IE 5.5000]>
<link rel="stylesheet" type="text/css" href="ie55.css" />
<![endif]-->
Target IE 6 and LOWER
<!--[if lt IE 7]>
<link rel="stylesheet" type="text/css" href="ie6-and-down.css" />
<![endif]-->
<!--[if lte IE 6]>
<link rel="stylesheet" type="text/css" href="ie6-and-down.css" />
<![endif]-->
Target IE 7 and LOWER
<!--[if lt IE 8]>
<link rel="stylesheet" type="text/css" href="ie7-and-down.css" />
<![endif]-->
<!--[if lte IE 7]>
<link rel="stylesheet" type="text/css" href="ie7-and-down.css" />
<![endif]-->
Target IE 8 and LOWER
<!--[if lt IE 9]>
<link rel="stylesheet" type="text/css" href="ie8-and-down.css" />
<![endif]-->
<!--[if lte IE 8]>
<link rel="stylesheet" type="text/css" href="ie8-and-down.css" />
<![endif]-->
Target IE 6 and HIGHER
<!--[if gt IE 5.5]>
<link rel="stylesheet" type="text/css" href="ie6-and-up.css" />
<![endif]-->
<!--[if gte IE 6]>
<link rel="stylesheet" type="text/css" href="ie6-and-up.css" />
<![endif]-->
Target IE 7 and HIGHER
<!--[if gt IE 6]>
<link rel="stylesheet" type="text/css" href="ie7-and-up.css" />
<![endif]-->
<!--[if gte IE 7]>
<link rel="stylesheet" type="text/css" href="ie7-and-up.css" />
<![endif]-->
Target IE 8 and HIGHER
<!--[if gt IE 7]>
<link rel="stylesheet" type="text/css" href="ie8-and-up.css" />
<![endif]-->
<!--[if gte IE 8]>
<link rel="stylesheet" type="text/css" href="ie8-and-up.css" />
<![endif]-->
Universal IE 6 CSS
Dealing with IE 6 and below is always an extra-special challenge. These days people are dropping support for it right and left, including major businesses, major web apps, and even governments. There is a better solution than just letting the site go to hell, and that is to server IE 6 and below a special stripped-down stylesheet, and then serve IE 7 and above (and all other browsers) the regular CSS. This is been coined the universal IE 6 CSS.
<!--[if !IE 6]><!-->
<link rel="stylesheet" type="text/css" media="screen, projection" href="REGULAR-STYLESHEET.css" />
<!--<![endif]-->
<!--[if gte IE 7]>
<link rel="stylesheet" type="text/css" media="screen, projection" href="REGULAR-STYLESHEET.css" />
<![endif]-->
<!--[if lte IE 6]>
<link rel="stylesheet" type="text/css" media="screen, projection" href="http://universal-ie6-css.googlecode.com/files/ie6.0.3.css" />
<![endif]-->
使用条件注释和一个样式表瞄准IE
A wrapper may be made to enclose the content of a page, and then you can write descendant CSS rules that mention that wrapper's ID or class name in the selector. But what if only IE thought that wrapper existed? Then those rules would only work for IE, while other browsers would ignore the rules completely.
<style>
/* all browsers make border red */
#anyelement{border:2pxsolidred;}
/* all browsers see this, but only IE thinks #IEroot exists as an element and makes border blue */