/* 全局样式 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary-color: #2563eb;
    --primary-dark: #1e40af;
    --secondary-color: #10b981;
    --text-dark: #1f2937;
    --text-light: #6b7280;
    --bg-light: #f9fafb;
    --bg-white: #ffffff;
    --border-color: #e5e7eb;
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
    --transition: all 0.3s ease;
}

body {
    font-family: 'Noto Sans SC', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    font-size: 16px;
    line-height: 1.6;
    color: var(--text-dark);
    background-color: var(--bg-white);
}

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

/* 导航栏 */
.navbar {
    background: var(--bg-white);
    box-shadow: var(--shadow-sm);
    position: sticky;
    top: 0;
    z-index: 1000;
    padding: 1rem 0;
}

.navbar .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.nav-brand h1 {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-color);
}

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

.nav-menu a {
    text-decoration: none;
    color: var(--text-dark);
    font-weight: 500;
    transition: var(--transition);
}

.nav-menu a:hover {
    color: var(--primary-color);
}

/* 按钮样式 */
.btn {
    display: inline-block;
    padding: 0.75rem 1.5rem;
    border-radius: 0.5rem;
    text-decoration: none;
    font-weight: 500;
    transition: var(--transition);
    border: none;
    cursor: pointer;
    font-size: 1rem;
}

.btn-primary {
    background: var(--primary-color);
    color: white;
}

.btn-primary:hover {
    background: var(--primary-dark);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.btn-secondary {
    background: var(--bg-light);
    color: var(--text-dark);
}

.btn-secondary:hover {
    background: var(--border-color);
}

.btn-outline {
    background: transparent;
    border: 2px solid var(--primary-color);
    color: var(--primary-color);
}

.btn-outline:hover {
    background: var(--primary-color);
    color: white;
}

/* 主横幅 */
.hero {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 6rem 0;
    text-align: center;
}

.hero-title {
    font-size: 3rem;
    font-weight: 900;
    margin-bottom: 1rem;
    line-height: 1.2;
}

.hero-subtitle {
    font-size: 1.25rem;
    margin-bottom: 3rem;
    opacity: 0.95;
}

.hero-stats {
    display: flex;
    justify-content: center;
    gap: 4rem;
    margin-bottom: 3rem;
}

.stat-item {
    text-align: center;
}

.stat-number {
    font-size: 2.5rem;
    font-weight: 900;
    margin-bottom: 0.5rem;
}

.stat-label {
    font-size: 1rem;
    opacity: 0.9;
}

.hero-cta {
    display: flex;
    gap: 1rem;
    justify-content: center;
}

/* 通用section样式 */
section {
    padding: 5rem 0;
}

.section-title {
    font-size: 2.5rem;
    font-weight: 700;
    text-align: center;
    margin-bottom: 1rem;
    color: var(--text-dark);
}

.section-subtitle {
    text-align: center;
    color: var(--text-light);
    font-size: 1.125rem;
    margin-bottom: 3rem;
}

/* 核心优势 */
.features {
    background: var(--bg-light);
}

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

.feature-card {
    background: white;
    padding: 2rem;
    border-radius: 1rem;
    text-align: center;
    transition: var(--transition);
    box-shadow: var(--shadow-sm);
}

.feature-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
}

.feature-icon {
    font-size: 3rem;
    margin-bottom: 1rem;
}

.feature-card h3 {
    font-size: 1.25rem;
    margin-bottom: 0.75rem;
    color: var(--text-dark);
}

.feature-card p {
    color: var(--text-light);
    line-height: 1.6;
}

/* 基础知识 */
.basics-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 2rem;
}

.basic-card {
    background: white;
    border: 1px solid var(--border-color);
    border-radius: 1rem;
    padding: 2rem;
    transition: var(--transition);
}

.basic-card:hover {
    box-shadow: var(--shadow-lg);
    transform: translateY(-3px);
}

.card-header {
    margin-bottom: 1rem;
}

.card-header h3 {
    font-size: 1.5rem;
    margin-bottom: 0.5rem;
}

.tag {
    display: inline-block;
    padding: 0.25rem 0.75rem;
    background: var(--primary-color);
    color: white;
    border-radius: 1rem;
    font-size: 0.875rem;
}

.card-desc {
    color: var(--text-light);
    margin-bottom: 1rem;
}

.card-list {
    list-style: none;
    margin-bottom: 1.5rem;
}

.card-list li {
    padding: 0.5rem 0;
    color: var(--text-dark);
}

.card-link {
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 500;
    transition: var(--transition);
}

.card-link:hover {
    color: var(--primary-dark);
}

/* 存储方案 */
.storage {
    background: var(--bg-light);
}

.storage-plans {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin-bottom: 2rem;
}

.plan-card {
    background: white;
    border-radius: 1rem;
    padding: 2rem;
    position: relative;
    transition: var(--transition);
    border: 2px solid transparent;
}

.plan-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
}

.plan-card.featured {
    border-color: var(--primary-color);
    transform: scale(1.05);
}

.plan-badge {
    position: absolute;
    top: -12px;
    right: 20px;
    background: var(--primary-color);
    color: white;
    padding: 0.5rem 1rem;
    border-radius: 1rem;
    font-size: 0.875rem;
    font-weight: 500;
}

.plan-header {
    text-align: center;
    margin-bottom: 2rem;
    padding-bottom: 2rem;
    border-bottom: 1px solid var(--border-color);
}

.plan-header h3 {
    font-size: 1.5rem;
    margin-bottom: 1rem;
}

.plan-price .price {
    font-size: 2.5rem;
    font-weight: 900;
    color: var(--primary-color);
}

.plan-price .period {
    color: var(--text-light);
    font-size: 1rem;
}

.plan-features {
    list-style: none;
    margin-bottom: 2rem;
}

.plan-features li {
    padding: 0.75rem 0;
    color: var(--text-dark);
}

.plan-features li.disabled {
    color: var(--text-light);
    opacity: 0.5;
}

.plan-card .btn {
    width: 100%;
    text-align: center;
}

.storage-note {
    background: white;
    padding: 2rem;
    border-radius: 1rem;
    border-left: 4px solid var(--secondary-color);
}

.storage-note h4 {
    margin-bottom: 0.5rem;
}

.storage-note p {
    color: var(--text-light);
}

/* 治疗应用 */
.therapy-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
}

.therapy-item {
    background: white;
    padding: 2rem;
    border-radius: 1rem;
    text-align: center;
    border: 1px solid var(--border-color);
    transition: var(--transition);
}

.therapy-item:hover {
    box-shadow: var(--shadow-md);
    transform: translateY(-3px);
}

.therapy-icon {
    font-size: 3rem;
    margin-bottom: 1rem;
}

.therapy-item h3 {
    font-size: 1.25rem;
    margin-bottom: 0.75rem;
}

.therapy-item p {
    color: var(--text-light);
    margin-bottom: 1rem;
}

.therapy-tag {
    display: inline-block;
    padding: 0.25rem 0.75rem;
    background: var(--bg-light);
    color: var(--text-dark);
    border-radius: 1rem;
    font-size: 0.875rem;
}

/* 前沿研究 */
.research {
    background: var(--bg-light);
}

.research-highlights {
    display: grid;
    gap: 2rem;
}

.research-card {
    background: white;
    padding: 2rem;
    border-radius: 1rem;
    border-left: 4px solid var(--primary-color);
    transition: var(--transition);
}

.research-card:hover {
    box-shadow: var(--shadow-md);
}

.research-date {
    color: var(--primary-color);
    font-weight: 500;
    margin-bottom: 0.5rem;
}

.research-card h3 {
    font-size: 1.5rem;
    margin-bottom: 1rem;
}

.research-card p {
    color: var(--text-light);
    margin-bottom: 1rem;
}

.research-link {
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 500;
}

/* 科普文章 */
.article-categories {
    display: flex;
    gap: 1rem;
    justify-content: center;
    margin-bottom: 3rem;
    flex-wrap: wrap;
}

.category-btn {
    padding: 0.5rem 1.5rem;
    border: 1px solid var(--border-color);
    background: white;
    border-radius: 2rem;
    cursor: pointer;
    transition: var(--transition);
    font-weight: 500;
}

.category-btn:hover,
.category-btn.active {
    background: var(--primary-color);
    color: white;
    border-color: var(--primary-color);
}

.articles-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin-bottom: 3rem;
}

.article-card {
    background: white;
    border: 1px solid var(--border-color);
    border-radius: 1rem;
    padding: 1.5rem;
    transition: var(--transition);
    cursor: pointer;
}

.article-card:hover {
    box-shadow: var(--shadow-lg);
    transform: translateY(-3px);
}

.article-tag {
    display: inline-block;
    padding: 0.25rem 0.75rem;
    background: var(--primary-color);
    color: white;
    border-radius: 1rem;
    font-size: 0.875rem;
    margin-bottom: 1rem;
}

.article-card h3 {
    font-size: 1.25rem;
    margin-bottom: 0.75rem;
    line-height: 1.4;
}

.article-card p {
    color: var(--text-light);
    margin-bottom: 1rem;
    line-height: 1.6;
}

.article-meta {
    display: flex;
    gap: 1.5rem;
    color: var(--text-light);
    font-size: 0.875rem;
}

.articles-more {
    text-align: center;
}

/* 常见问题 */
.faq {
    background: var(--bg-light);
}

.faq-list {
    max-width: 800px;
    margin: 0 auto;
}

.faq-item {
    background: white;
    padding: 2rem;
    border-radius: 1rem;
    margin-bottom: 1rem;
    border-left: 4px solid var(--primary-color);
}

.faq-item h3 {
    font-size: 1.125rem;
    margin-bottom: 1rem;
    color: var(--text-dark);
}

.faq-item p {
    color: var(--text-light);
    line-height: 1.8;
}

/* 联系我们 */
.contact-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 3rem;
}

.contact-info h3,
.contact-form h3 {
    font-size: 1.5rem;
    margin-bottom: 1.5rem;
}

.contact-item {
    display: flex;
    gap: 1rem;
    margin-bottom: 1.5rem;
}

.contact-icon {
    font-size: 2rem;
}

.contact-item strong {
    display: block;
    margin-bottom: 0.25rem;
}

.contact-item p {
    color: var(--text-light);
}

.contact-form form {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.contact-form input,
.contact-form select,
.contact-form textarea {
    padding: 0.75rem;
    border: 1px solid var(--border-color);
    border-radius: 0.5rem;
    font-family: inherit;
    font-size: 1rem;
}

.contact-form input:focus,
.contact-form select:focus,
.contact-form textarea:focus {
    outline: none;
    border-color: var(--primary-color);
}

/* 页脚 */
.footer {
    background: var(--text-dark);
    color: white;
    padding: 3rem 0 1.5rem;
}

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

.footer-section h4 {
    margin-bottom: 1rem;
}

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

.footer-section ul li {
    margin-bottom: 0.5rem;
}

.footer-section a {
    color: rgba(255, 255, 255, 0.8);
    text-decoration: none;
    transition: var(--transition);
}

.footer-section a:hover {
    color: white;
}

.footer-bottom {
    text-align: center;
    padding-top: 1.5rem;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
}

.disclaimer {
    font-size: 0.875rem;
    opacity: 0.7;
    margin-top: 0.5rem;
}

/* 响应式设计 */
@media (max-width: 768px) {
    .nav-menu {
        display: none;
    }

    .hero-title {
        font-size: 2rem;
    }

    .hero-stats {
        flex-direction: column;
        gap: 2rem;
    }

    .hero-cta {
        flex-direction: column;
    }

    .section-title {
        font-size: 2rem;
    }

    .storage-plans {
        grid-template-columns: 1fr;
    }

    .plan-card.featured {
        transform: none;
    }

    .contact-content {
        grid-template-columns: 1fr;
    }
}

/* ============================================================
   多页面结构新增样式
   ============================================================ */

/* 页面横幅（子页面通用） */
.page-hero {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 4rem 0;
    text-align: center;
}

.page-hero h2 {
    font-size: 2.5rem;
    font-weight: 900;
    margin-bottom: 0.75rem;
}

.page-hero p {
    font-size: 1.2rem;
    opacity: 0.9;
}

/* 详情页主体 */
.detail-content {
    padding: 4rem 0;
}

.detail-content .container {
    display: flex;
    gap: 2.5rem;
    align-items: flex-start;
}

.detail-body {
    flex: 1;
    min-width: 0;
}

.detail-body h3 {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-dark);
    margin-top: 2.5rem;
    margin-bottom: 1rem;
    padding-bottom: 0.5rem;
    border-bottom: 2px solid var(--primary-color);
}

.detail-body h3:first-child {
    margin-top: 0;
}

.detail-body p {
    color: var(--text-light);
    line-height: 1.9;
    margin-bottom: 1rem;
}

.detail-body ul {
    margin: 1rem 0 1.5rem 1.5rem;
    color: var(--text-light);
    line-height: 1.9;
}

.detail-body ul li {
    margin-bottom: 0.5rem;
    padding-left: 0.5rem;
}

.detail-body strong {
    color: var(--text-dark);
}

/* 详情页侧边栏 */
.detail-sidebar {
    width: 280px;
    flex-shrink: 0;
    position: sticky;
    top: 80px;
}

.sidebar-card {
    background: var(--bg-light);
    border-radius: 1rem;
    padding: 1.5rem;
    margin-bottom: 1.5rem;
    border: 1px solid var(--border-color);
}

.sidebar-card h4 {
    font-size: 1.1rem;
    margin-bottom: 1rem;
    color: var(--text-dark);
}

.sidebar-card ul {
    list-style: none;
}

.sidebar-card ul li {
    padding: 0.5rem 0;
    color: var(--text-light);
    border-bottom: 1px solid var(--border-color);
    font-size: 0.95rem;
}

.sidebar-card ul li:last-child {
    border-bottom: none;
}

.sidebar-card ul li a {
    color: var(--primary-color);
    text-decoration: none;
    transition: var(--transition);
}

.sidebar-card ul li a:hover {
    color: var(--primary-dark);
}

/* 详情页CTA */
.detail-cta {
    margin-top: 3rem;
    padding-top: 2rem;
    border-top: 1px solid var(--border-color);
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
}

/* 研究日期标签 */
.research-date-tag {
    display: inline-block;
    background: var(--primary-color);
    color: white;
    padding: 0.25rem 0.75rem;
    border-radius: 0.5rem;
    font-size: 0.875rem;
    font-weight: 500;
    margin-bottom: 1rem;
}

/* CTA section */
.cta-section {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 4rem 0;
}

.cta-section .section-title {
    color: white;
}

.cta-section .section-subtitle {
    color: rgba(255,255,255,0.9);
}

.cta-section .btn-primary {
    background: white;
    color: var(--primary-color);
}

.cta-section .btn-primary:hover {
    background: var(--bg-light);
}

.cta-section .btn-outline {
    border-color: white;
    color: white;
}

.cta-section .btn-outline:hover {
    background: white;
    color: var(--primary-color);
}

/* 导航下拉菜单 */
.nav-dropdown {
    position: relative;
}

.nav-dropdown .dropdown-menu {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    background: white;
    border-radius: 0.5rem;
    box-shadow: var(--shadow-lg);
    min-width: 180px;
    padding: 0.5rem 0;
    z-index: 1001;
    list-style: none;
}

.nav-dropdown:hover .dropdown-menu {
    display: block;
}

.dropdown-menu li a {
    display: block;
    padding: 0.5rem 1rem;
    color: var(--text-dark);
    text-decoration: none;
    font-size: 0.95rem;
    transition: var(--transition);
}

.dropdown-menu li a:hover {
    background: var(--bg-light);
    color: var(--primary-color);
}

/* 导航active状态 */
.nav-menu .active a {
    color: var(--primary-color);
}

/* 移动端菜单按钮 */
.mobile-menu-btn {
    display: none;
    background: none;
    border: none;
    font-size: 1.5rem;
    cursor: pointer;
    color: var(--text-dark);
    padding: 0.25rem 0.5rem;
}

/* 响应式设计增强 */
@media (max-width: 768px) {
    .nav-menu {
        display: none;
        flex-direction: column;
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background: white;
        box-shadow: var(--shadow-lg);
        padding: 1rem 2rem;
        gap: 0;
        z-index: 999;
    }

    .nav-menu.open {
        display: flex;
    }

    .nav-menu li {
        padding: 0.75rem 0;
        border-bottom: 1px solid var(--border-color);
    }

    .nav-menu li:last-child {
        border-bottom: none;
    }

    .nav-dropdown .dropdown-menu {
        position: static;
        box-shadow: none;
        padding-left: 1rem;
    }

    .nav-dropdown:hover .dropdown-menu {
        display: none;
    }

    .nav-dropdown.open .dropdown-menu {
        display: block;
    }

    .mobile-menu-btn {
        display: block;
    }

    .page-hero h2 {
        font-size: 1.8rem;
    }

    .page-hero {
        padding: 3rem 0;
    }

    .detail-content .container {
        flex-direction: column;
    }

    .detail-sidebar {
        width: 100%;
        position: static;
    }

    .detail-body h3 {
        font-size: 1.3rem;
    }

    .hero-title {
        font-size: 2rem;
    }

    .hero-stats {
        flex-direction: column;
        gap: 2rem;
    }

    .hero-cta {
        flex-direction: column;
    }

    .section-title {
        font-size: 2rem;
    }

    .storage-plans {
        grid-template-columns: 1fr;
    }

    .plan-card.featured {
        transform: none;
    }

    .contact-content {
        grid-template-columns: 1fr;
    }
}