console 命令行工具 X clear

console

!<html>

    <div >
        鼠标进入变半透明
    </div>
    <style>
        div{
            width:100px;
            height:100px;
            border:1px solid #000;
            background: #f00;
        }
        div:hover{
            opacity :0.5;
        }
    </style>
</html>