实现效果
![](data:image/png;base64,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)
实现代码
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<link rel="shortcut icon" href="resources/img/logo-color.png" type="image/x-icon">
<title>测试</title>
<style>
.out-div {
color: #FFFFFF;
font-size: 16px;
line-height: 40px;
display: inline-block;
height: 40px;
width: 200px;
text-align: center;
border-radius: 5px;
margin-left: 32px;
vertical-align: top;
background-color: maroon;
}
.arrow {
width: 0px;
height: 0px;
border-top: 10px solid transparent;
border-right: 10px solid;
border-bottom: 10px solid transparent;
position: absolute;
margin-left: -10px;
margin-top: 10px;
border-right-color: maroon;
}
</style>
</head>
<body>
<div class="out-div">
<div class="arrow" ></div>
<span>这是一个提示框</span>
</div>
</body>
</html>