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

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    line-height: 1.6;
    color: #333;
    font-size: 16px; /* 全龄友好：比标准稍大的字体 */
}

header {
    background-color: #fff;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
    position: fixed;
    width: 100%;
    top: 0;
    z-index: 1000;
}

nav {
    max-width: 1200px;
    margin: 0 auto;
    padding: 1rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 1.5rem;
    font-weight: bold;
    color: #2E86AB; /* 守护蓝 */
}

nav ul {
    list-style: none;
    display: flex;
    gap: 2rem;
}

nav a {
    text-decoration: none;
    color: #2E86AB; /* 守护蓝 */
    font-weight: 500;
    transition: color 0.3s ease;
}

nav a:hover {
    color: #FF9800; /* 温暖橙 */
}

.language-switcher select {
    background: #fff;
    border: 2px solid #2E86AB;
    border-radius: 6px;
    padding: 0.4rem 0.8rem;
    color: #2E86AB;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.3s ease;
}

.language-switcher select:hover {
    background: #2E86AB;
    color: white;
}

.language-switcher select:focus {
    outline: none;
    box-shadow: 0 0 0 3px rgba(46, 134, 171, 0.3);
}

main {
    margin-top: 80px;
    padding: 2rem;
    max-width: 1200px;
    margin-left: auto;
    margin-right: auto;
}

.hero {
    text-align: center;
    padding: 4rem 0;
}

.hero h1 {
    font-size: 2.8rem; /* 全龄友好：更大的标题 */
    margin-bottom: 1rem;
    color: #2E86AB; /* 守护蓝 */
    font-weight: 700;
}

.hero-subtitle {
    font-size: 1.2rem;
    color: #666;
    margin-bottom: 2rem;
    max-width: 800px;
    margin-left: auto;
    margin-right: auto;
}

.hero-highlights {
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    gap: 1.5rem;
    margin-top: 2rem;
}

.highlight-item {
    background: linear-gradient(135deg, #2E86AB, #4CAF50);
    color: white;
    padding: 0.8rem 1.2rem;
    border-radius: 25px;
    font-size: 0.9rem;
    font-weight: 500;
    box-shadow: 0 4px 8px rgba(46, 134, 171, 0.3);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.highlight-item:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 12px rgba(46, 134, 171, 0.4);
}

.feature-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin: 2rem 0;
}

.feature-item {
    padding: 2rem;
    background: #f8f9fa;
    border-radius: 12px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.05);
    transition: all 0.3s ease;
    border-left: 4px solid transparent;
}

.feature-item:hover {
    transform: translateY(-3px);
    box-shadow: 0 6px 16px rgba(0,0,0,0.1);
    border-left-color: #4CAF50;
}

.feature-item.featured {
    background: linear-gradient(135deg, #fff, #f0f8ff);
    border: 2px solid #2E86AB;
    border-left: 4px solid #2E86AB;
}

/* 核心价值部分 */
.value-proposition {
    margin: 4rem 0;
    padding: 3rem 0;
    background: linear-gradient(135deg, #f8f9fa, #e9ecef);
}

.value-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 2rem;
    margin: 2rem 0;
}

.value-item {
    text-align: center;
    padding: 2rem;
    background: white;
    border-radius: 16px;
    box-shadow: 0 4px 12px rgba(0,0,0,0.1);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.value-item:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 24px rgba(0,0,0,0.15);
}

.value-icon {
    font-size: 3rem;
    margin-bottom: 1rem;
    display: block;
}

.value-item h3 {
    color: #2E86AB;
    margin-bottom: 1rem;
    font-size: 1.3rem;
}

.value-item p {
    color: #666;
    line-height: 1.7;
}

/* 功能展示部分 */
.features {
    margin: 4rem 0;
}

.features h2, .value-proposition h2 {
    text-align: center;
    color: #2E86AB;
    font-size: 2.2rem;
    margin-bottom: 1rem;
}

.feature-item h3 {
    color: #2E86AB;
    margin-bottom: 1rem;
    font-size: 1.2rem;
}

.feature-item ul {
    margin: 1rem 0;
    padding-left: 1.5rem;
    color: #666;
}

.feature-item li {
    margin: 0.5rem 0;
}

/* 订阅计划部分 */
.subscription-info {
    margin: 4rem 0;
    padding: 3rem 0;
    background: linear-gradient(135deg, #2E86AB, #4CAF50);
    border-radius: 20px;
    color: white;
}

.subscription-info h2 {
    text-align: center;
    color: white;
    font-size: 2.2rem;
    margin-bottom: 2rem;
}

.subscription-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    max-width: 800px;
    margin: 0 auto;
}

.plan-card {
    background: white;
    border-radius: 16px;
    padding: 2.5rem;
    text-align: center;
    box-shadow: 0 8px 24px rgba(0,0,0,0.1);
    transition: transform 0.3s ease;
    color: #333;
}

.plan-card:hover {
    transform: translateY(-5px);
}

.plan-card.pro {
    border: 3px solid #FF9800;
    position: relative;
}

.plan-card.pro::before {
    content: "推荐";
    position: absolute;
    top: -12px;
    right: 20px;
    background: #FF9800;
    color: white;
    padding: 0.5rem 1rem;
    border-radius: 20px;
    font-size: 0.8rem;
    font-weight: 600;
}

.plan-card h3 {
    color: #2E86AB;
    font-size: 1.5rem;
    margin-bottom: 1rem;
}

.plan-price {
    font-size: 1.3rem;
    font-weight: 600;
    color: #4CAF50;
    margin-bottom: 2rem;
}

.plan-features {
    list-style: none;
    padding: 0;
}

.plan-features li {
    padding: 0.8rem 0;
    border-bottom: 1px solid #eee;
    font-size: 1rem;
}

.plan-features li:last-child {
    border-bottom: none;
}

/* FAQ部分 */
.faq {
    margin: 4rem 0;
    padding: 3rem 0;
}

.faq h2 {
    text-align: center;
    color: #2E86AB;
    font-size: 2.2rem;
    margin-bottom: 2rem;
}

.faq-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 2rem;
    margin: 2rem 0;
}

.faq-item {
    margin: 0;
    padding: 2rem;
    background: white;
    border-radius: 12px;
    box-shadow: 0 4px 12px rgba(0,0,0,0.08);
    transition: all 0.3s ease;
    border-left: 4px solid #4CAF50;
}

.faq-item:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 16px rgba(0,0,0,0.12);
}

.faq-item h3 {
    color: #2E86AB;
    margin-bottom: 1rem;
    font-size: 1.2rem;
}

.faq-answer {
    color: #666;
    line-height: 1.6;
}

.faq-answer p {
    margin: 0.8rem 0;
}

.faq-answer strong {
    color: #FF9800;
}

/* 快速帮助部分 */
.quick-help {
    margin: 4rem 0;
}

.quick-help h2 {
    text-align: center;
    color: #2E86AB;
    font-size: 2.2rem;
    margin-bottom: 2rem;
}

.help-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 2rem;
}

.help-item {
    padding: 2rem;
    background: white;
    border-radius: 12px;
    box-shadow: 0 4px 12px rgba(0,0,0,0.08);
    transition: all 0.3s ease;
    border-top: 4px solid #4CAF50;
}

.help-item:hover {
    transform: translateY(-3px);
    box-shadow: 0 8px 20px rgba(0,0,0,0.12);
}

.help-item h3 {
    color: #2E86AB;
    margin-bottom: 1rem;
    font-size: 1.2rem;
}

.help-link {
    display: inline-block;
    margin-top: 1rem;
    color: #FF9800;
    text-decoration: none;
    font-weight: 500;
    transition: color 0.3s ease;
}

.help-link:hover {
    color: #2E86AB;
}

/* 联系我们部分 */
.contact {
    text-align: center;
    padding: 4rem 0;
    background: #f8f9fa;
    border-radius: 20px;
    margin: 4rem 0;
}

.contact h2 {
    color: #2E86AB;
    font-size: 2.2rem;
    margin-bottom: 1rem;
}

.contact-info {
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    gap: 2rem;
    margin-top: 2rem;
}

.contact-item {
    background: white;
    padding: 1.5rem;
    border-radius: 12px;
    box-shadow: 0 4px 8px rgba(0,0,0,0.05);
    min-width: 250px;
}

.privacy-content {
    max-width: 800px;
    margin: 0 auto;
    margin-top: 100px; /* 增加上边距，避免被导航栏遮挡 */
    padding: 2rem;
}

.privacy-content section {
    margin: 2rem 0;
}

.privacy-content h1 {
    color: #2E86AB;
    margin-bottom: 1rem;
}

.privacy-content h2 {
    color: #2E86AB;
    margin: 1.5rem 0 1rem;
}

.privacy-content ul {
    margin-left: 2rem;
    margin-top: 1rem;
}

footer {
    text-align: center;
    padding: 2rem;
    background: #f8f9fa;
    margin-top: 4rem;
}

@media (max-width: 768px) {
    /* 导航栏移动端优化 */
    nav {
        padding: 0.8rem 1rem;
        flex-direction: column;
        gap: 1rem;
    }
    
    nav ul {
        gap: 0.8rem;
        flex-wrap: wrap;
        justify-content: center;
        font-size: 0.9rem;
    }
    
    .language-switcher {
        order: -1; /* 语言切换器放在最上方 */
    }
    
    .language-switcher select {
        padding: 0.4rem 0.6rem;
        font-size: 0.9rem;
        border-radius: 8px;
    }
    
    /* 主要内容区域调整 */
    main {
        padding: 1rem;
        margin-top: 100px; /* 增加上边距适应新的导航栏高度 */
    }
    
    /* 标题优化 */
    .hero h1 {
        font-size: 1.8rem; /* 减小字体避免换行 */
        line-height: 1.3;
        padding: 0 0.5rem;
    }
    
    .hero-subtitle {
        font-size: 1rem;
        padding: 0 1rem;
        line-height: 1.5;
    }
    
    /* 高亮按钮优化 */
    .hero-highlights {
        flex-direction: column;
        align-items: center;
        gap: 1rem;
        margin-top: 2rem;
        padding: 0 1rem;
    }
    
    .highlight-item {
        width: 100%;
        max-width: 280px;
        text-align: center;
        padding: 1rem 1.5rem;
        font-size: 1rem;
    }
    
    /* 网格布局优化 */
    .feature-grid, .value-grid, .help-grid, .faq-grid {
        grid-template-columns: 1fr;
        gap: 1.5rem;
    }
    
    .subscription-grid {
        grid-template-columns: 1fr;
        gap: 1.5rem;
        padding: 0 1rem;
    }
    
    /* 联系信息优化 */
    .contact-info {
        flex-direction: column;
        align-items: center;
        gap: 1rem;
    }
    
    .contact-item {
        min-width: auto;
        width: 100%;
        max-width: 300px;
        padding: 1rem;
        font-size: 0.95rem;
    }
    
    /* 隐私页面优化 */
    .privacy-content {
        margin-top: 120px;
        padding: 1rem;
    }
    
    /* 各部分间距优化 */
    .value-proposition, .subscription-info, .contact {
        margin: 2rem 0;
        padding: 2rem 1rem;
    }
    
    .faq, .features, .quick-help {
        padding: 2rem 1rem;
    }
    
    /* 卡片内容优化 */
    .value-item, .feature-item, .help-item, .faq-item {
        padding: 1.5rem;
    }
    
    /* 计划卡片优化 */
    .plan-card {
        padding: 2rem 1.5rem;
    }
    
    .plan-card.pro::before {
        right: 15px;
        font-size: 0.75rem;
    }
}

/* 超小屏幕优化 (iPhone SE等) */
@media (max-width: 480px) {
    .hero h1 {
        font-size: 1.6rem;
    }
    
    .hero-subtitle {
        font-size: 0.95rem;
    }
    
    .highlight-item {
        font-size: 0.9rem;
        padding: 0.8rem 1.2rem;
    }
    
    nav ul {
        gap: 0.6rem;
        font-size: 0.85rem;
    }
    
    .language-switcher select {
        font-size: 0.85rem;
        padding: 0.3rem 0.5rem;
    }
}

.privacy-content h3 {
    color: #2E86AB;
    margin: 1rem 0;
    font-size: 1.1rem;
}