CSS 代码规范排序：提高代码可读性和维护性

<style>
    body {
        background-color: #f2f2f2;
        font-family: Arial, sans-serif;
    }
    
    .center {
        display: flex;
        flex-direction: column;
        align-items: center;
        justify-content: center;
        height: 100vh;
    }
    
    form {
        display: flex;
        flex-direction: column;
        align-items: center;
        padding: 20px;
        border-radius: 5px;
        box-shadow: 0 0 10px rgba(0, 0, 0, 0.2);
        background-color: #fff;
    }
    
    label {
        margin-bottom: 10px;
    }
    
    input[type='password'] {
        padding: 10px;
        border-radius: 5px;
        border: 1px solid #ccc;
        font-size: 16px;
        box-sizing: border-box;
    }
    
    button {
        margin-top: 20px;
        padding: 10px 20px;
        border-radius: 5px;
        background-color: #2ecc71;
        color: #fff;
        font-size: 16px;
        border: none;
        cursor: pointer;
        box-sizing: border-box;
    }
    
    .refresh-button {
        background-color: #4CAF50;
        color: white;
        border: none;
        padding: 10px 20px;
        text-align: center;
        text-decoration: none;
        display: inline-block;
        font-size: 16px;
        border-radius: 5px;
        cursor: pointer;
        transition: background-color 0.3s ease;
    }
    
    .refresh-button:hover {
        background-color: #3e8e41;
    }
</style>