@media screen and (max-width: 1200px) {
.srch_index .srch_box{ left:20%; top:50%;}
}
@media screen and (min-width: 1201px) {
.srch_index .srch_box{ left:30%; top:50%;}
}
@media screen and (min-width: 1900px) {
.srch_index .srch_box{ left:20%; top:50%;}
}
原文：http://my.oschina.net/sniperLi/blog/498757