手机上最细的线

 

/* 手机上最细的线*/
.border-line-top {
  position: relative;
  border: none;
  clear: both;
}
.border-line-top:before {
  content: "";
  position: absolute;
  left: 0;
  width: 200%;
  height: 0;
  border-bottom: 1px solid #ddd;
  -webkit-transform-origin: left top;
  transform-origin: left top;
  -webkit-transform: scale3d(0.5, 0.5, 0.5);
  transform: scale3d(0.5, 0.5, 0.5);
  top: -1px;
}
.border-line-bottom {
  position: relative;
  border: none;
  clear: both;
}
.border-line-bottom:after {
  content: "";
  position: absolute;
  left: 0;
  width: 200%;
  height: 0;
  border-bottom: 1px solid #ddd;
  -webkit-transform-origin: left top;
  transform-origin: left top;
  -webkit-transform: scale3d(0.5, 0.5, 0.5);
  transform: scale3d(0.5, 0.5, 0.5);
  bottom: -1px;
}