iPhoneX、iPhone11、iphoneXR 等全屏手机，由于下方有一个小长条，到底吸底按钮等元素被下方小长条遮住，需向上移动一点，将小长条留出距离，

适配方法如下：

js:

  let deviceHeight = window.screen.heightlet deviceWidth = window.screen.widthlet DPR = window.devicePixelRatiolet condition1 = (deviceWidth === 375) && (deviceHeight === 812) && (DPR === 3)let condition2 = (deviceWidth === 414) && (deviceHeight === 896) && (DPR === 2)let condition3 = (deviceWidth === 414) && (deviceHeight === 896) && (DPR === 3)if (condition1 || condition2 || condition3) {this.isIphoneX = true}

css:

@media only 
screen and (device-width: 375px) and (device-height: 812px) and (-webkit-device-pixel-ratio: 3) , 
screen and (device-width: 414px) and (device-height: 896px) and (-webkit-device-pixel-ratio: 2), 
screen and (device-width: 414px) and (device-height: 896px) and (-webkit-device-pixel-ratio: 3){/*增加底部适配层*/.fit-iphonex {box-sizing: content-box;padding-bottom: 34px;&:after {content: '';z-index: 9998;position: fixed;left: 0;bottom: 0;width: 100%;height: 34px;background: #F9F9F9;}}
}