给你举些例子吧:
要适用于大多数智能机:
@media screen and (max-width:480px) { … }
禁止一些旧的浏览器看到iphone或者ipad的样式:
@media only screen and (max-width: 480px;) { … }
适用于大多数平板:
@media screen and (min-width:400px) and (max-width:800px) { … }
只适用于Ipad:
@media only screen and (min-device-width: 768px) and (max-device-width: 1024px) { … }
只适用于xoom:
@media only screen and (min-device-width: 1280px) and (max-device-width: 800px) { … }
差不多就是这个意思