移动端css适配

 /* iphoneX、iphoneXs */
        @media only screen and (device- 375px) and (device-height: 812px) and (-webkit-device-pixel-ratio: 3){ 
            .bottom{bottom: 34px;}
            .lastp{padding-bottom: 3.2rem;}
        }
        /* iphone Xs Max */
        @media only screen and (device- 414px) and (device-height: 896px) and (-webkit-device-pixel-ratio:3) {
            .bottom{bottom: 34px;}
            .lastp{padding-bottom: 3.2rem;}
        }

        /* iphone XR */
        @media only screen and (device- 414px) and (device-height: 896px) and (-webkit-device-pixel-ratio:2){ 
            .bottom{bottom: 34px;}
            .lastp{padding-bottom: 3.2rem;}
        }