body {
    margin: 0;
    padding: 0;
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    background-color: #f0f2f5; /* 浅灰背景 */
    font-family: Arial, sans-serif;
}

.container {
    text-align: center;
}

h1 {
    color: #333;
    font-size: 3rem;
    transition: color 0.3s ease;
}