* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

/* 语言切换器 */
.language-switcher {
    position: fixed;
    top: 10px;
    right: 10px;
    z-index: 1000;
    display: flex;
    gap: 5px;
}

.lang-btn {
    padding: 6px 12px;
    border: 1px solid #007bff;
    background-color: white;
    color: #007bff;
    border-radius: 4px;
    cursor: pointer;
    font-size: 12px;
    font-weight: 500;
    transition: all 0.3s ease;
}

.lang-btn:hover {
    background-color: #f0f8ff;
}

.lang-btn.active {
    background-color: #007bff;
    color: white;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    background-color: #f5f5f5;
    color: #333;
    line-height: 1.6;
}

.container {
    display: flex;
    flex-direction: column;
    min-height: 100vh;
    background-color: #fff;
    margin: 0 auto;
}

/* ===== 上部分 - 页头 ===== */
.header {
    width: 100%;
    background-color: #f0f0f0;
    height: 150px;
    display: flex;
    align-items: center;
    padding: 0;
    text-align: center;
}

.banner-image {
    max-width: 1200px;
    width: 100%;
    height: 150px;
    display: block;
    margin: 0 auto;
    border-radius: 8px;
    object-fit: cover;
}

.banner-container {
    position: relative;
    max-width: 1200px;
    width: 100%;
    margin: 0 auto;
}

.banner-text {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    color: #fff;
    text-shadow: 0 2px 4px rgba(0, 0, 0, 0.3);
}

.banner-title {
    font-size: 32px;
    font-weight: bold;
    margin: 0;
    margin-bottom: 5px;
}

.banner-subtitle {
    font-size: 14px;
    margin: 0;
    opacity: 0.95;
}

/* ===== 中间部分 - 主要内容 ===== */
.main-content {
    flex: 1;
    width: 100%;
    padding: 40px 0;
    background-color: #fff;
}

.content-wrapper {
    display: flex;
    max-width: 1200px;
    margin: 0 auto;
    gap: 40px;
    padding: 0 20px;
}

/* ===== 左边导航栏 ===== */
.sidebar {
    width: 220px;
    flex-shrink: 0;
}

.navigation h3 {
    margin-bottom: 20px;
    font-size: 18px;
    color: #222;
    border-bottom: 2px solid #007bff;
    padding-bottom: 10px;
}

.nav-list {
    list-style: none;
}

.nav-link {
    display: block;
    padding: 12px 15px;
    margin-bottom: 8px;
    text-decoration: none;
    color: #555;
    background-color: #f9f9f9;
    border-left: 3px solid transparent;
    transition: all 0.3s ease;
    border-radius: 4px;
    cursor: pointer;
    font-size: 14px;
}

.nav-link:hover {
    color: #007bff;
    background-color: #f0f8ff;
    border-left-color: #007bff;
}

.nav-link.active {
    color: #fff;
    background-color: #007bff;
    border-left-color: #0056b3;
    font-weight: 600;
}

/* ===== 右边产品内容 ===== */
.product-section {
    flex: 1;
    min-width: 0;
}

.product-content {
    display: none;
    animation: fadeIn 0.3s ease-in;
}

.product-content.active {
    display: block;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.product-content h2 {
    font-size: 28px;
    margin-bottom: 15px;
    color: #222;
    border-bottom: 2px solid #007bff;
    padding-bottom: 10px;
}

.product-content h3 {
    font-size: 18px;
    margin-top: 25px;
    margin-bottom: 12px;
    color: #222;
    border-left: 3px solid #007bff;
    padding-left: 10px;
}

.product-content p {
    margin-bottom: 20px;
    color: #666;
    font-size: 16px;
    line-height: 1.8;
}

.product-content ul {
    list-style: none;
    margin-left: 0;
}

.product-content li {
    padding: 10px 0;
    padding-left: 25px;
    position: relative;
    color: #555;
    font-size: 15px;
}

.product-content li:before {
    content: "✓";
    position: absolute;
    left: 0;
    color: #007bff;
    font-weight: bold;
}

/* ===== 下部分 - 页脚 ===== */
.footer {
    width: 100%;
    background-color: #f0f0f0;
    color: #333;
    display: flex;
    align-items: center;
    margin-top: auto;
    padding: 25px 0;
}

.footer-content {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
    width: 100%;
    text-align: center;
}

.footer-content h3 {
    font-size: 16px;
    margin-bottom: 12px;
    color: #222;
    font-weight: 600;
}

.footer-content p {
    margin-bottom: 8px;
    font-size: 15px;
    color: #666;
}

.footer-content a {
    color: #007bff;
    text-decoration: none;
    transition: all 0.3s ease;
}

.footer-content a:hover {
    color: #0056b3;
    text-decoration: underline;
}

.separator {
    margin: 0 12px;
    color: #ddd;
}

.footer-content .copyright {
    margin-top: 12px;
    padding-top: 12px;
    border-top: 1px solid #ddd;
    font-size: 13px;
    color: #888;
}

/* ===== 响应式设计 ===== */
@media (max-width: 768px) {
    .content-wrapper {
        flex-direction: column;
        gap: 20px;
        padding: 0 15px;
    }

    .sidebar {
        width: 100%;
    }

    .nav-list {
        display: flex;
        flex-wrap: wrap;
        gap: 10px;
    }

    .nav-link {
        flex: 1;
        min-width: 120px;
        text-align: center;
        margin-bottom: 0;
    }

    .product-content h2 {
        font-size: 24px;
    }

    .main-content {
        padding: 20px 0;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0;
    }

    .header {
        padding: 10px 0;
    }

    .banner-image {
        border-radius: 0;
    }

    .content-wrapper {
        padding: 0 10px;
    }

    .product-content h2 {
        font-size: 20px;
    }

    .footer-content {
        padding: 0 10px;
    }
}