/* --- 全局与变量 --- */
:root {
    --footer-bg-color: #fff;
    --footer-text-color: #ecf0f1;
    --footer-link-color: #bdc3c7;
    --footer-heading-color: #ffffff;
    --accent-color: #3498db;
    --footer-border-color: #34495e;
}

/* --- 页脚主体样式 --- */
.site-footer {
    background-color: var(--card-bg-color);
    color: var(--light-text-color);
    padding: 60px 0 20px;
    width: 100%;
    margin-top: 3rem;
    border-top: 1px solid var(--border-color);
}

.footer-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

.footer-content {
    display: grid;
    grid-template-columns: 1fr 1fr 1fr;
    gap: 40px;
    margin-bottom: 40px;
}

.footer-section h3 {
    color: var(--footer-heading-color);
    font-size: 1.2rem;
    margin-bottom: 20px;
    text-transform: uppercase;
    letter-spacing: 1px;
}

.footer-section p,
.footer-section ul {
    color: var(--footer-link-color);
}

.footer-section ul {
    list-style: none;
}

.footer-section ul li {
    margin-bottom: 12px;
}

.footer-section a {
    color: var(--footer-link-color);
    text-decoration: none;
    transition: color 0.3s ease;
}

.footer-section a:hover {
    color: var(--primary-color);
}

/* --- 关于我们区域 --- */
.footer-about .logo {
    font-size: 1.8rem;
    font-weight: bold;
    color: var(--primary-color);
    margin-bottom: 15px;
}

.footer-about p {
    line-height: 1.8;
}

.social-links {
    margin-top: 20px;
}

.social-links a {
    display: inline-block;
    width: 40px;
    height: 40px;
    line-height: 40px;
    text-align: center;
    background-color: var(--footer-border-color);
    border-radius: 50%;
    margin-right: 10px;
    transition: background-color 0.3s ease;
}

.social-links a:hover {
    background-color: var(--accent-color);
    color: #fff;
}

/* --- 订阅区域 --- */
.subscribe-form p {
    margin-bottom: 15px;
}

.subscribe-form form {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.subscribe-form input[type="email"] {
    width: 100%;
    padding: 12px;
    border: 1px solid var(--footer-border-color);
    background-color: transparent;
    color: var(--footer-text-color);
    border-radius: 4px;
}

.subscribe-form input[type="email"]::placeholder {
    color: var(--footer-link-color);
}

.subscribe-form button {
    padding: 12px 20px;
    background-color: var(--accent-color);
    color: #fff;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    font-size: 1rem;
    transition: background-color 0.3s ease;
}

.subscribe-form button:hover {
    background-color: #2980b9;
}

/* --- 底部版权栏 --- */
.footer-bottom {
    border-top: 1px solid var(--footer-border-color);
    padding-top: 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
}

.footer-bottom p {
    font-size: 0.9rem;
}

.footer-bottom-links a {
    margin-left: 20px;
    font-size: 0.9rem;
}

/* --- 移动端适配 (核心部分) --- */
@media (max-width: 768px) {
    .footer-content {
        grid-template-columns: 1fr; /* 关键：将多列布局变为单列 */
        gap: 30px;
    }

    /* 使用 details/summary 实现折叠效果 */
    .footer-section h3 {
        display: none; /* 隐藏原始的 h3 标题 */
    }

    .footer-section {
        padding-bottom: 10px;
    }

    .footer-section:last-child {
        border-bottom: none;
    }

    .footer-section details {
        width: 100%;
    }

    .footer-section summary {
        font-size: 1.2rem;
        padding: 15px 0;
        cursor: pointer;
        list-style: none; /* 隐藏默认的三角箭头 */
        display: flex;
        justify-content: space-between;
        align-items: center;
        outline: none;
    }

    .footer-section summary::-webkit-details-marker {
        display: none; /* 兼容 Webkit 内核浏览器 */
    }

    /* 自定义折叠箭头 */
    .footer-section summary::after {
        content: '+';
        font-size: 1.5rem;
        font-weight: bold;
        transition: transform 0.3s ease;
    }

    .footer-section details[open] summary::after {
        transform: rotate(45deg);
    }

    .footer-section details[open] summary {
        border-bottom: 1px solid var(--footer-border-color);
    }

    .footer-section .summary-content {
        padding: 0 0 15px 0;
    }

    /* 底部版权栏在移动端垂直居中 */
    .footer-bottom {
        flex-direction: column;
        text-align: center;
        gap: 15px;
    }

    .footer-bottom-links a {
        margin: 0 10px;
    }
}
select {
    padding: 8px 12px;
    font-size: 16px;
    border-radius: 5px;
    border: 1px solid #ccc;
}

#selected-country {
    margin-top: 15px;
    font-weight: bold;
}