1. rem + @media 适配手机页面
rem 用的 flexible.js 插件
@media 用来调整细节
/*iphone4/4s */
@media (device-height:480px) and (-webkit-min-device-pixel-ratio:2) {}
/*iphone5 */
@media (device-height:568px) and (-webkit-min-device-pixel-ratio:2) {}
/*iphone6 */
@media (device-height:667px) and (-webkit-min-device-pixel-ratio:2) {}
/*iphone6 Plus */
@media (device-height:736px) and (-webkit-min-device-pixel-ratio:2) {}