<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title></title>
<style>
div{
width: 100px;
height: 100px;
background: #FF0000;
}
div:hover{/*鼠标滑动颜色改变*/
background: #0000FF;
}
</style>
</head>
<body>
<div onclick="alert(123)"></div>/*onclick="alert(123)" 点击出现提示123*/
</body>
</html>
