css 兼容 各类手机的写法 待续

@media (device-height:480px) and (-webkit-min-device-pixel-ratio:2){/* 兼容iphone4/4s */
.class{}
}
@media (device-height:568px) and (-webkit-min-device-pixel-ratio:2){/* 兼容iphone5 */
.class{}
}

/* 上面的写法合并后 */
@media (device-height:480px) and (-webkit-min-device-pixel-ratio:2),(device-height:568px) and (-webkit-min-device-pixel-ratio:2){/* 兼容iphone4/4s5/5 */ 
.class{} 
}

或者根据不同的手机 引入样式

<link rel="stylesheet" media="(device-height: 480px) and (-webkit-min-device-pixel-ratio:2)" href="iphone4.css" />
<link rel="stylesheet" media="(device-height: 568px)and (-webkit-min-device-pixel-ratio:2)" href="iphone5.css" />