示例

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<style>
    body{
        margin: 0;
        padding: 0;
    }
    .wrapper{
        height: 100vh;
        align-items: center;
        justify-content: center;
        display: flex;
        flex-direction: column;
        gap: 3px;
    }

    .wrapper:hover{
        cursor: pointer;
        opacity: 0.6;
        transition: all 0.25s ease;
    }

    .wrapper.active #line2{
        opacity: 0;
    }

    .wrapper.active #line1{
        transform: rotate(45deg) translate(4px, 4.3px);
        width: 21px;
    }

    .wrapper.active #line3{
        transform: rotate(-45deg) translate(4px, -4.3px);
        width: 21px;
    }

    .line{
        background-color: black;
        width: 20px;
        height: 3px;
        transition: all 0.25s ease;
    }
</style>
<script>
    onload = () => {
        let ele_wrapper = document.querySelector('.wrapper');
        ele_wrapper.onclick = () => {
            if(ele_wrapper.classList.contains('active')){
                ele_wrapper.classList.remove('active');
            }else{
                ele_wrapper.classList.add('active');
            }
        }
    }
</script>
<body>
    <div class="wrapper">
        <div class="line" id="line1"></div>
        <div class="line" id="line2"></div>
        <div class="line" id="line3"></div>
    </div>
</body>
</html>

A Student on the way to full stack of Web3.