- pointer-events:none; 屏蔽鼠标事件
- opacity:value; filter:alpha(opacity=value)透明,内容会跟着透明如果不想内容透明解决方案?1.把background用rgba实现 2. 用定位实现,背景和内容单独出来,用定位使其叠加在一起

只有划到红框内才触发hover事件
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Document</title>
<style>
*{margin:0;padding:0}
div{width:300px;height:300px;position:relative;border: 1px solid red;}
nav{width:300px;height:300px;background:
position:absolute;
top:0;
left:300px;
transition: 1s;
opacity: 0;
pointer-events: none;
}
div:hover nav{left: 0;opacity: .5;}
</style>
</head>
<body>
<div>
<img src="https://www.baidu.com/img/flexible/logo/pc/result.png" alt="">
<nav>哈</nav>
</div>
</body>
</html>