<!DOCTYPE html>
<html>
<head>
<title>0.5px的线</title>
<style type="text/css">
.bd-t {
position: relative;
margin-top: 200px;
}
.bd-t:after {
content: " ";
position: absolute;
left: 0;
top: 0;
100%;
height: 1px;
background-color: #000;
/* 如果不用 background-color, 使用 border-top:1px solid #e0e0e0; */
-webkit-transform: scaleY(.5);
transform: scaleY(.5);
}
</style>
</head>
<body>
<div class="bd-t"></div>
</body>
</html>