移动端1px边框解决方案，兼容性较好，推荐使用

这是阿里去啊的解决方案，与weui解决1px的方法类似，只不过这个方案加了dpr=3的媒体查询，废话不多说，看代码：

/*retina 1px border start*/
.retinabt,.retinabb,.retinabl,.retinabr,.retinab { position: relative;}
.retinabt:before,.retinabb:after {pointer-events: none;position: absolute;content: ""; height: 1px; background: rgba(32,35,37,.24);left: 0;right: 0}
.retinabt:before {top: 0}
.retinabb:after {bottom: 0}
.retinabl:before,.retinabr:after {pointer-events: none;position: absolute;content: ""; width: 1px; background: rgba(32,35,37,.24); top: 0; bottom: 0}
.retinabl:before {left: 0}
.retinabr:after {right: 0}
.retinab:after {position: absolute;content: "";top: 0;left: 0; -webkit-box-sizing: border-box; box-sizing: border-box; width: 100%; height: 100%; border: 1px solid rgba(32,35,37,.24); pointer-events: none}
 
@media (-webkit-min-device-pixel-ratio:1.5),(min-device-pixel-ratio:1.5),(min-resolution: 144dpi),(min-resolution:1.5dppx) {
.retinabt:before,.retinabb:after {-webkit-transform:scaleY(.5);transform: scaleY(.5) }
.retinabl:before,.retinabr:after {-webkit-transform: scaleX(.5); transform: scaleX(.5) }
.retinab:after { width: 200%; height: 200%;-webkit-transform: scale(.5); transform: scale(.5) }
.retinabt:before,.retinabl:before,.retinab:after {-webkit-transform-origin: 0 0;transform-origin: 0 0}
.retinabb:after,.retinabr:after { -webkit-transform-origin: 100% 100%;transform-origin: 100% 100%}
}
 
@media (-webkit-device-pixel-ratio:1.5) {
.retinabt:before,.retinabb:after { -webkit-transform: scaleY(.6666); transform: scaleY(.6666) }
.retinabl:before,.retinabr:after {-webkit-transform: scaleX(.6666); transform: scaleX(.6666)}
.retinab:after {width: 150%; height: 150%;-webkit-transform: scale(.6666); transform: scale(.6666) }
}
 
@media (-webkit-device-pixel-ratio:3) {
.retinabt:before,.retinabb:after { -webkit-transform: scaleY(.3333); transform: scaleY(.3333)}
.retinabl:before,.retinabr:after { -webkit-transform: scaleX(.3333); transform: scaleX(.3333)}
.retinab:after {width: 300%;height: 300%; -webkit-transform: scale(.3333);transform: scale(.3333)}
}