移动端1像素问题
min-height: 4rem;
margin-top: -1px;
background: -webkit-gradient(linear,left top,left bottom,from(#fff),color-stop(.5,#fff),color-stop(.5,transparent)) top left no-repeat,-webkit-gradient(linear,left top,left bottom,from(#fff),to(#fff)) bottom left no-repeat,-webkit-gradient(linear,left top,left bottom,from(#e5e5e5),color-stop(.5,#e5e5e5),color-stop(.5,transparent)) top left no-repeat,-webkit-gradient(linear,left top,left bottom,from(#e5e5e5),to(#e5e5e5)) bottom left no-repeat,#fff;
background: -webkit-linear-gradient(90deg,#fff,#fff) top left no-repeat,-webkit-linear-gradient(270deg,#fff,#fff) bottom left no-repeat,-webkit-linear-gradient(90deg,#e5e5e5,#e5e5e5,rgba(229,229,229,0)) top left no-repeat,-webkit-linear-gradient(270deg,#e5e5e5,#e5e5e5,rgba(229,229,229,0)) bottom left no-repeat,#fff;
background: linear-gradient(0deg,#fff,#fff) top left no-repeat,linear-gradient(180deg,#fff,#fff) bottom left no-repeat,linear-gradient(0deg,#e5e5e5,#e5e5e5,rgba(229,229,229,0)) top left no-repeat,linear-gradient(180deg,#e5e5e5,#e5e5e5,rgba(229,229,229,0)) bottom left no-repeat,#fff;
-webkit-background-size: 0 0,0 0,100% 1px,100% 1px;
-webkit-box-align: center;
-webkit-align-items: center;