body {font-size:12px; font-family:'Microsoft Yahei'; overflow-x:hidden;}
body, div, dl, dt, dd, ul, ol, nl, li, h1, h2, h3, h4, h5, h6, p, span, a, b, strong, object, iframe, label, img, blockquote, ins, del, select, form, input, textarea, table, caption, tbody, tfoot, thead, tr, th, td, article, aside, canvas, details, figcaption, figure, footer, header, hgroup, menu, nav, section, summary, time, mark, audio, video {margin:0;padding:0}
article, aside, details, figcaption, figure, footer, header, hgroup, menu, nav, section {display:block}
a{text-decoration:none;} 
li{list-style:none outside none;}
.none{ display:none;}

/*内容*/

.nav{ width:960px; margin:0;}
.nav li{ float:left; width:237px; height:295px; margin-right:0px;}
.nav li a{ display:block; width:100%; height:100%; background:url(img/nav.png) no-repeat; text-indent:-999em;
transition: all .3s ease;
-webkit-transition: all .3s ease;
-moz-transition: all .3s ease;
-o-transition: all .3s ease;}
.nav li.nav1 a{ background-position:0 0;}
.nav li.nav2 a{ background-position:-257px 0;}
.nav li.nav3 a{ background-position:-507px 0;}
.nav li.nav4 a{ background-position:-752px 0;}
.nav li.nav1 a:hover,.nav li.nav2.cur a{ background-position:0 -295px;}
.nav li.nav2 a:hover,.nav li.nav2.cur a{ background-position:-257px -295px;}
.nav li.nav3 a:hover,.nav li.nav3.cur a{ background-position:-507px -295px;}
.nav li.nav4 a:hover,.nav li.nav4.cur a{ background-position:-752px -295px;}