body {
    font-family: Arial, sans-serif;
    text-align: center;
    margin-top: 50px;
}

h1 {
    color: #333;
}

    footer {
        position: fixed;
        bottom: 0;
        left: 0;
        right: 0;
        background-color: #333;
        color: #fff;
        text-align: center;
        padding: 10px 0;
    }
    
    body {
        margin-bottom: 60px; /* 为footer留出空间 */
    }
    
    span {
        color: black;
    }