div的hover显示隐藏

<style>
        .contain{
            width: 100%;
        }
        .box{
            margin: 100px auto;
            width: 500px;
            height: 500px;
            border: 1px solid #000;
        }
        .box1{
            width: 200px;
            height: 200px;
            background-color: #efefef;
            opacity: 0;
            pointer-events: none;
            transition: linear 0.3s;
        }
        .box:hover .box1{
            opacity: 1;
            margin-top: 200px;
        }
    style>

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盒子1

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