Use CSS hack technology to solve browser compatibility problems

/* CSS Attribute-level Hack */color: red;/* all browsers can recognize */_ color: red;/* Only IE6 recognizes */* color: red; /* IE6, IE7 recognition */+ color: red;/* IE6, IE7 recognition */* + color: red;/* IE6, IE7 recognition */[color: red; /* IE6, IE7 recognition */color: red \ 9;/* IE6, IE7, IE8, and IE9 recognition */color: red \ 0; /* IE8 and IE9 recognition */color: red \ 9 \ 0;/* Only IE9 recognition */color: red \ 0;/* Only IE9 recognition */color: red! Important;/* IE6 not recognized! For more information about important, see */strong/* CSS character-level Hack */* html # demo {color: red;}/* Only IE6 recognition */* + html # demo {color: red;}/* Only IE7 recognition */body: nth-of-type (1) # demo {color: red ;} /* IE9 +, FF3.5 +, Chrome, Safari, and Opera can recognize */head: first-child + body # demo {color: red ;} /* IE7 +, FF, Chrome, Safari, and Opera can be recognized */: root # demo {color: red \ 9;}:/* Only IE9 recognition */---------------------- --------------------------------------/* For more information about Hack, see */<! -- [If IE]> the content here is only visible to IE <! [Endif] --> <! -- [If IE 6]> the content here is only visible to IE6.0 <! [Endif] --> <! -- [If IE 7]> the content here is only visible to IE7.0 <! [Endif] --> <! -- [If gte IE 6]> IE6 and IE6 and later versions can be recognized <! [Endif] --> <! -- [If lt IE 7]> versions earlier than IE7 and IE7 are recognizable <! [Endif] --> <! -- [If gte IE 7]> IE7 and IE7 versions can be identified <! [Endif] --> <! -- [If! IE]> the content here is only non-IE visible <! [Endif] -->