正常写法，不同手机上线很粗很丑，UI很细腻

.item {border-bottom:1px solid #eeeeee&:last-child{border-bottom:none;}
}

解决方案

.item {position: relative;&:after{content: '';position: absolute;bottom: 0px;left: 0px;width: 100%;height: 1px;background: #eeeeee;transform:  scaleY(0.5);}&:last-child:after {display: none;}
}