body {
    background-color: #eaf6ff;
    font-family: 'Segoe UI', sans-serif;
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 50px;
    min-height: 100vh;
    margin: 0;
}

.container {
    background-color: #ffffff;
    padding: 30px 40px;
    border-radius: 10px;
    box-shadow: 0 0 15px rgba(0, 123, 255, 0.1);
    width: 100%;
    max-width: 450px;
    box-sizing: border-box;
}

h2 {
    text-align: center;
    color: #0056b3;
    margin-bottom: 25px;
    font-size: 24px;
}

label {
    font-weight: bold;
    margin-top: 10px;
    display: block;
    color: #333;
    font-size: 15px;
}

input {
    width: 100%;
    padding: 12px;
    margin-top: 6px;
    margin-bottom: 16px;
    border-radius: 6px;
    border: 1px solid #ccc;
    box-sizing: border-box;
    font-size: 15px;
}

input:focus {
    border-color: #007bff;
    outline: none;
}

button {
    width: 100%;
    background-color: #007bff;
    border: none;
    color: white;
    padding: 14px;
    font-weight: bold;
    border-radius: 6px;
    cursor: pointer;
    transition: background-color 0.3s;
    font-size: 16px;
}

button:hover {
    background-color: #0056b3;
}

ul {
    color: red;
    margin-bottom: 15px;
    padding-left: 20px;
    font-size: 14px;
}

.success-message {
    color: green;
    margin-bottom: 15px;
    text-align: center;
    font-size: 14px;
}

p {
    text-align: center;
    margin-top: 10px;
    font-size: 14px;
}

a {
    color: #007bff;
    text-decoration: none;
}

a:hover {
    text-decoration: underline;
}

/* ✅ Mobile 优化 */
@media (max-width: 768px) {
    body {
        padding: 20px;
    }

    .container {
        padding: 20px;
    }

    h2 {
        font-size: 20px;
        margin-bottom: 20px;
    }

    input,
    button {
        font-size: 15px;
        padding: 12px;
    }

    label {
        font-size: 14px;
    }

    p {
        font-size: 13px;
    }

    ul {
        font-size: 13px;
    }
}