<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>制作三角形箭头</title>
<style>
.arrow{
width:0;
height:0;
border-top:50px solid #000; /*设置并显示上边框*/
border-bottom:none; /*不设置下边框*/
border-left:50px solid transparent; /*设置但隐藏左边框*/
border-right:50px solid transparent; /*设置但隐藏右边框*/
}
.arrow:hover{
border-top:none; /*鼠标经过时，不设置上边框*/
border-bottom:50px solid #000; /*鼠标经过时，设置并显示下边框*/
}
</style>
</head>
<body>
<div class="arrow"></div>
</body>
</html>
.btn{
width:100px;
height:100px;
background:#ccc;
border-radius:50%;
box-shadow:5px 5px 10px #000; /*设置外阴影*/
}
.btn:active{
background:#bbb;
box-shadow:5px 5px 10px #000 inset; /*设置内阴影*/
}
.btn div{
font-size:30px;
font-family:"微软雅黑";
color:blue;
float:left;
margin-top:28px;
margin-left:20px;
}
