CSS Browser Hacks

/***** Selector Hacks ******/

/* IE 6 and below */
* html #uno  { color: red }

/* IE 7 and below */
*:first-child+html #dos { color: red }

/* IE 7 and modern browsers */
html>body #tres { color: red }

/* All IE versions, including IE8 Standards Mode */
#somediv { color: blue\9 }

/* IE8 Standards-Mode */
#comediv { color /*\**/: blue\9 }

/* Modern browsers (not IE 7) */
html>/**/body #cuatro { color: red }

/* Opera 9.27 and below */
html:first-child #cinco { color: red }

/* Safari */
html[xmlns*=""] body:last-child #seis { color: red }

/*safari 3+, chrome 1+, opera9+, ff 3.5+ */
body:nth-of-type(1) #siete { color: red }

/* safari 3+, chrome 1+, opera9+, ff 3.5+ */
body:first-of-type #ocho {  color: red }

/* saf3, chrome1+ */
@media screen and (-webkit-min-device-pixel-ratio:0) {
   #diez  { background: #FFDECE; border: 2px solid #ff0000  }
}

/***** Attribute Hacks ******/

/* ie6 and below */
#once { _color:blue }

/* ie7 and below */
#doce { *color: blue } /* or #color:blue */

/* 'Modern Browsers' includes IE8, whether you agree or not.. */

참고
http://ajaxian.com/archives/css-browser-hacks
http://paulirish.com/2009/browser-specific-css-hacks

출처 : http://uidev.pe.kr/