移动端 1px 线的实现

高清屏的1px线的实现，适用于 dpr：2 的情况。

<html>
<head>
<meta charset=“utf-8” />
<meta name=“viewport” content=“width=device-width, initial-scale=1.0, minimum-scale=1.0, maximum-scale=1.0, user-scalable=no” />
<meta name=“msapplication-tap-highlight” content=“no” />
<title>高清屏1px线的实现</title>
</head>
<body>
<div class=“border_gradient”>1.使用渐变实现，使用两种颜色填充 1px 宽内容</div>
<div class=“border_scale”>2.使用缩放实现，对 1px 高度线条进行0.5倍缩放</div>
<div class=“border_base64”>3.base64 编码实现</div>
<div class=“border_svg”>4.base64 编码嵌入SVG实现</div>
</body>
</html>

div {
width: 100vw;
height: 80px;
margin: 30px auto;
background-color: rgba(0, 0, 0, 0.1);
text-align: center;
padding-top: 20px;
font-size: 16px;
box-sizing: border-box;
}
/*border-top:1px*/
.border_normal,
.border_gradient,
.border_scale,
.border_boxshadow,
.border_base64,
.border_svg {
border-top: 1px solid #999;
}
@media (-webkit-min-device-pixel-ratio: 2), (min-resolution: 192dpi) {
.border_gradient {
background-image: linear-gradient(to top, transparent 50%, #999 50%);
background–size: 100% 1px;
background-repeat: no-repeat;
background-position: top center;
border-top: 0 none;
padding-top: 1px;
}
.border_scale {
position: relative;
padding-top: 1px;
border-top: 0 none;
}
.border_scale:before {
content: “”;
position: absolute;
top: 0;
left: 0;
width: 200%;
border-top: 1px solid #999;
transform: scale(0.5);
transform-origin: 0 0;
box-sizing: border-box;
}
.border_base64 {
padding-top: 1px;
border-top: 0 none;
background-image: url(data:image/png;
base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAACCAYAAACZgbYnAAAAAXNSR0IArs4c6QAAAARnQU1BAACxjwv8YQUAAAAJcEhZcwAADsMAAA7DAcdvqGQAAAAQSURBVBhXY5g5c+Z/BhAAABRcAsvqBShzAAAAAElFTkSuQmCC);
background-position: 0 0;
background-repeat: repeat-x;
background–size: 1px 1px;
}
.border_svg {
border-top: 0 none;
background-image: url(“data:image/svg+xml;utf8,<svg xmlns=’http://www.w3.org/2000/svg’ width=’100%’ height=’1′><rect fill=’#999′ x=’0′ y=’0.5′ width=’100%’ height=’0.5′ /></svg>”);
background-position: 0 0;
background-repeat: no-repeat;
}
}