@media (device-height:480px) and (-webkit-min-device-pixel-ratio:2){/* 兼容iphone4/4s */
}
@media (device-height:568px) and (-webkit-min-device-pixel-ratio:2){/* 兼容iphone5 */
}
@media (device-height:667px) and (-webkit-min-device-pixel-ratio:2){/* 兼容iphone6 */
}
@media (device-height:736px) and (-webkit-min-device-pixel-ratio:2){/* 兼容iphone6 Plus */
}