@media all and (min-width: 800px) { /*#nav { width: 300px; float: left; margin-right: 20px; } #grid { width: 450px; float: left; }*/ #pageone{width:640px;margin:0 auto;position:relative;} /* 屏幕大于800 页面宽度设为640 */ } @media all and (max-width: 799px) { /*#nav { width: 100%; } #grid { width: 100%; }*/ } /* 参考: http://www.ibm.com/developerworks/cn/mobile/mo-jquery-responsive-design/index.html */