css 3の未読メッセージの赤い点
<html lang="zh-CN">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8"/>
<style>
.red-point{
position: relative;
}
.red-point::before{
content: " ";
border: 3px solid red;/* */
border-radius:3px;/* */
position: absolute;
z-index: 1000;
right: 0%;
margin-right: -5px;
margin-top: -5px;
}
style>
head>
<body>
<span class="red-point">hello worldspan>
body>
html>