利用 :before 和 :after 伪类添加样式
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>css对话框箭头</title>
<style>
.comment{
300px;
border: 1px solid #376956;
position: relative;
background-color: #D0E9FF;
padding: 10px 20px;
border-radius: 8px;
position: relative;
margin-left: 20px;
}
.comment:before, .comment:after {
content: "";
display: block;
border- 12px;
position: absolute;
top: 20px;
left: -24px;
border-style: solid dashed dashed;
border-color: transparent #376956 transparent transparent;
font-size: 0;
line-height: 0;
}
.comment:after {
top: 20px;
left: -23px;
border-color: transparent #D0E9FF transparent transparent;
}
</style>
<body>
<div class="comment">
<p>内容内容内容内容内容</p>
<p>内容内容内容内容内容</p>
</div>
</body>
</html>
内容内容内容内容内容
内容内容内容内容内容