css hacks [selectors]

while applying the styles to HTML pages as a web page programmer you come across various browsers like internet explorer, firefox, safari, opera and many more. Each browser does its own interpretation of the CSS properties and renders a page. Following are few selectors use to hack IE

IE 6 and below
    * html {}
IE 7 and below
    *:first-child+html {} * html {}
IE 7 only
    *:first-child+html {}
IE 7 and modern browsers only
    html>body {}
Modern browsers only (not IE 7)
    html>/**/body {}
Recent Opera versions 9 and below
    html:first-child {}