/*手机*/  @media screen and (max-width:600px){
        #header,#content,#footer{width:400px;}     .right,.center{
   margin-top:10px;}     .left,.right{
   height:100px;}     .center{
   height:200px;}  }  /*平板*/  @media screen and (min-width:600px) and (max-width:960px){
         #header,#content,#footer{width:600px;}  .right{
   display:none;}  .left,.center{
   height:400px;float:left;}  .left{
   width:160px;margin-right:10px;}  .center{
   width:430px;}  }  /*PC*/  @media screen and (min-width:960px){
         #header,#content,#footer{width:960px;}  .left,.center,.right{
   height:400px;float:left;}  .left{
   width:200px;margin-right:10px;}  .center{
   width:540px;margin-right:10px;}  .right{
   width:200px;}   }