/* 库悦科技企业官网样式文件 */

/* CSS变量定义 - 亮色主题 */
:root {
    --bg-primary: #ffffff;
    --bg-secondary: #f8fafc;
    --bg-tertiary: #e2e8f0;
    --text-primary: #1e293b;
    --text-secondary: #64748b;
    --text-light: #ffffff;
    --accent-primary: #2563eb;
    --accent-secondary: #60a5fa;
    --border-color: rgba(255, 255, 255, 0.2);
    --shadow-light: rgba(0, 0, 0, 0.1);
    --shadow-medium: rgba(0, 0, 0, 0.15);
    --navbar-bg: rgba(255, 255, 255, 0.9);
    --card-bg: #ffffff;
}

/* 暗黑主题变量 */
[data-theme="dark"] {
    --bg-primary: #0f172a;
    --bg-secondary: #1e293b;
    --bg-tertiary: #334155;
    --text-primary: #f1f5f9;
    --text-secondary: #cbd5e1;
    --text-light: #f1f5f9;
    --accent-primary: #3b82f6;
    --accent-secondary: #60a5fa;
    --border-color: rgba(255, 255, 255, 0.1);
    --shadow-light: rgba(0, 0, 0, 0.3);
    --shadow-medium: rgba(0, 0, 0, 0.4);
    --navbar-bg: rgba(15, 23, 42, 0.9);
    --card-bg: #1e293b;
}

/* 重置样式和基础设置 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Noto Sans SC', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    line-height: 1.6;
    color: var(--text-primary);
    background-color: var(--bg-primary);
    transition: background-color 0.3s ease, color 0.3s ease;
}

/* 容器样式 */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}



/* 导航栏样式 */
.navbar {
    position: fixed;
    top: 0;
    width: 100%;
    background: transparent;
    backdrop-filter: blur(0px);
    box-shadow: none;
    z-index: 1000;
    transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
}

/* 滚动后的导航栏样式 */
.navbar.scrolled {
    background: var(--navbar-bg);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    box-shadow: 0 8px 32px var(--shadow-medium);
    border-bottom: 1px solid var(--border-color);
}

/* 为不支持backdrop-filter的浏览器提供备用样式 */
@supports not (backdrop-filter: blur(20px)) {
    .navbar.scrolled {
        background: rgba(255, 255, 255, 0.95);
        box-shadow: 0 8px 32px rgba(0, 0, 0, 0.2);
    }
}

/* 暗黑模式下的导航栏背景 */
[data-theme="dark"] .navbar.scrolled {
    background: rgba(15, 23, 42, 0.95);
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.nav-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 2rem;
    max-width: 1200px;
    margin: 0 auto;
}

.nav-logo {
    display: flex;
    align-items: center;
    gap: 12px;
}

.logo-img {
    height: 40px;
    width: auto;
    transition: all 0.3s ease;
}

.logo-text {
    display: flex;
    flex-direction: column;
    line-height: 1;
}

.nav-logo h2 {
    color: white;
    font-weight: 700;
    font-size: 1.8rem;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.3);
    transition: all 0.3s ease;
    margin: 0;
    line-height: 1;
}

.logo-subtitle {
    color: rgba(255, 255, 255, 0.8);
    font-size: 0.7rem;
    font-weight: 400;
    text-shadow: 1px 1px 2px rgba(0, 0, 0, 0.3);
    transition: all 0.3s ease;
    margin-top: 2px;
    letter-spacing: 0.5px;
}

.navbar.scrolled .nav-logo h2 {
    color: #2563eb;
    text-shadow: none;
}

.navbar.scrolled .logo-subtitle {
    color: rgba(37, 99, 235, 0.7);
    text-shadow: none;
}

/* 暗黑模式下的logo */
[data-theme="dark"] .navbar.scrolled .nav-logo h2 {
    color: var(--text-primary);
    text-shadow: none;
}

[data-theme="dark"] .navbar.scrolled .logo-subtitle {
    color: var(--text-secondary);
    text-shadow: none;
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 2rem;
    align-items: center;
    margin: 0;
    padding: 0;
}

.nav-item {
    display: flex;
    align-items: center;
}

.nav-link {
    text-decoration: none;
    color: white;
    font-weight: 500;
    transition: all 0.3s ease;
    position: relative;
    text-shadow: 1px 1px 2px rgba(0, 0, 0, 0.3);
    display: block;
    line-height: 1;
}

.nav-link:hover {
    color: #60a5fa;
}

.navbar.scrolled .nav-link {
    color: #333;
    text-shadow: none;
}

.navbar.scrolled .nav-link:hover {
    color: #2563eb;
}

/* 暗黑模式下的导航链接 */
[data-theme="dark"] .navbar.scrolled .nav-link {
    color: var(--text-primary);
    text-shadow: none;
}

[data-theme="dark"] .navbar.scrolled .nav-link:hover {
    color: var(--accent-secondary);
}

[data-theme="dark"] .navbar.scrolled .nav-link::after {
    background-color: var(--accent-secondary);
}

.nav-link::after {
    content: '';
    position: absolute;
    width: 0;
    height: 2px;
    bottom: -5px;
    left: 0;
    background-color: #60a5fa;
    transition: width 0.3s ease;
}

.nav-link:hover::after {
    width: 100%;
}

.navbar.scrolled .nav-link::after {
    background-color: var(--accent-primary);
}

/* 主题切换按钮 */
.theme-toggle {
    background: none;
    border: 2px solid var(--text-light);
    border-radius: 50%;
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: all 0.3s ease;
    margin: 0;
    padding: 0;
}

.theme-toggle:hover {
    background: rgba(255, 255, 255, 0.1);
    transform: scale(1.1);
}

.navbar.scrolled .theme-toggle {
    border-color: var(--text-primary);
}

.navbar.scrolled .theme-toggle:hover {
    background: rgba(37, 99, 235, 0.1);
}

.theme-icon {
    font-size: 1.2rem;
    transition: transform 0.3s ease;
}

.theme-toggle:hover .theme-icon {
    transform: rotate(20deg);
}

/* 暗黑模式下的主题切换按钮 */
[data-theme="dark"] .theme-toggle {
    border-color: white;
    color: white;
}

[data-theme="dark"] .navbar.scrolled .theme-toggle {
    border-color: var(--text-primary);
    color: var(--text-primary);
}

[data-theme="dark"] .navbar.scrolled .theme-toggle:hover {
    background: rgba(241, 245, 249, 0.1);
}

/* 移动端导航菜单 */
.nav-toggle {
    display: none;
    flex-direction: column;
    cursor: pointer;
}

.bar {
    width: 25px;
    height: 3px;
    background-color: white;
    margin: 3px 0;
    transition: 0.3s;
    box-shadow: 1px 1px 2px rgba(0, 0, 0, 0.3);
}

.navbar.scrolled .bar {
    background-color: #333;
    box-shadow: none;
}

/* 轮播图区域 */
.hero-section {
    position: relative;
    height: 100vh;
    overflow: hidden;
}

.hero-slider {
    position: relative;
    width: 100%;
    height: 100%;
}

.slide {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    opacity: 0;
    transition: opacity 1s ease-in-out;
}

.slide.active {
    opacity: 1;
}

.slide img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.slide-content {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    text-align: center;
    color: white;
    z-index: 2;
}

.slide-content h1 {
    font-size: 3.5rem;
    font-weight: 700;
    margin-bottom: 1rem;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.5);
}

.slide-content p {
    font-size: 1.5rem;
    margin-bottom: 2rem;
    text-shadow: 1px 1px 2px rgba(0, 0, 0, 0.5);
}

.cta-button {
    display: inline-block;
    padding: 15px 30px;
    background: linear-gradient(135deg, #2563eb, #1d4ed8);
    color: white;
    text-decoration: none;
    border-radius: 50px;
    font-weight: 600;
    transition: all 0.3s ease;
    box-shadow: 0 4px 15px rgba(37, 99, 235, 0.3);
}

.cta-button:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(37, 99, 235, 0.4);
}

/* 轮播图控制按钮 */
.slider-controls {
    position: absolute;
    top: 50%;
    width: 100%;
    display: flex;
    justify-content: space-between;
    padding: 0 2rem;
    z-index: 3;
}

.prev-btn, .next-btn {
    background: rgba(255, 255, 255, 0.2);
    border: none;
    color: white;
    font-size: 2rem;
    padding: 10px 15px;
    border-radius: 50%;
    cursor: pointer;
    transition: all 0.3s ease;
}

.prev-btn:hover, .next-btn:hover {
    background: rgba(255, 255, 255, 0.3);
    transform: scale(1.1);
}

/* 轮播图指示点 */
.slider-dots {
    position: absolute;
    bottom: 2rem;
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    gap: 10px;
    z-index: 3;
}

.dot {
    width: 12px;
    height: 12px;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.5);
    cursor: pointer;
    transition: all 0.3s ease;
}

.dot.active {
    background: white;
    transform: scale(1.2);
}

/* 公司简介区域 */
.intro-section {
    padding: 100px 0;
    background: linear-gradient(135deg, var(--bg-secondary) 0%, var(--bg-tertiary) 100%);
}

.intro-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    align-items: center;
}

.intro-text h2 {
    font-size: 2.5rem;
    color: var(--text-primary);
    margin-bottom: 1.5rem;
    font-weight: 700;
}

.intro-text p {
    font-size: 1.1rem;
    color: var(--text-secondary);
    margin-bottom: 2rem;
    line-height: 1.8;
}

.intro-stats {
    display: flex;
    gap: 2rem;
}

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

.stat-item h3 {
    font-size: 2.5rem;
    color: var(--accent-primary);
    font-weight: 700;
    margin-bottom: 0.5rem;
}

.stat-item p {
    color: var(--text-secondary);
    font-weight: 500;
}

.intro-image img {
    width: 100%;
    border-radius: 15px;
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.1);
    transition: transform 0.3s ease;
}

.intro-image img:hover {
    transform: translateY(-5px);
}

/* 通用区域样式 */
.section-header {
    text-align: center;
    margin-bottom: 4rem;
}

.section-header h2 {
    font-size: 2.5rem;
    color: var(--text-primary);
    margin-bottom: 1rem;
    font-weight: 700;
}

.section-header p {
    font-size: 1.1rem;
    color: var(--text-secondary);
    max-width: 600px;
    margin: 0 auto;
}

/* 关于我们区域 */
.about-section {
    padding: 100px 0;
    background: var(--bg-primary);
    overflow-x: hidden;
}

.about-tabs {
    display: flex;
    justify-content: center;
    gap: 1rem;
    margin-bottom: 3rem;
}

.tab-button {
    padding: 12px 24px;
    border: 2px solid var(--border-color);
    background: var(--bg-primary);
    color: var(--text-secondary);
    border-radius: 25px;
    cursor: pointer;
    transition: all 0.3s ease;
    font-weight: 500;
}

.tab-button.active {
    background: var(--accent-primary);
    color: var(--text-light);
    border-color: var(--accent-primary);
}

.tab-button:hover {
    border-color: var(--accent-primary);
    color: var(--accent-primary);
}

.tab-button.active:hover {
    color: var(--text-light);
}

.tab-content {
    display: none;
    animation: fadeIn 0.5s ease-in-out;
}

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

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
}

/* 时间线样式 */
.timeline {
    position: relative;
    max-width: 800px;
    margin: 0 auto;
    overflow-x: hidden;
}

.timeline::before {
    content: '';
    position: absolute;
    left: 50%;
    top: 0;
    bottom: 0;
    width: 2px;
    background: var(--accent-primary);
    transform: translateX(-50%);
}

.timeline-item {
    position: relative;
    margin-bottom: 3rem;
    display: flex;
    align-items: center;
}

.timeline-item:nth-child(odd) {
    flex-direction: row;
}

.timeline-item:nth-child(even) {
    flex-direction: row-reverse;
}

.timeline-year {
    background: var(--accent-primary);
    color: var(--text-light);
    padding: 10px 20px;
    border-radius: 25px;
    font-weight: 700;
    font-size: 1.1rem;
    min-width: 80px;
    text-align: center;
    position: relative;
    z-index: 2;
}

.timeline-content {
    flex: 1;
    padding: 0 2rem;
    background: var(--bg-secondary);
    border-radius: 10px;
    padding: 1.5rem;
    margin: 0 2rem;
    box-shadow: 0 4px 15px var(--shadow-light);
}

.timeline-content h3 {
    color: var(--text-primary);
    margin-bottom: 0.5rem;
    font-weight: 600;
}

.timeline-content p {
    color: var(--text-secondary);
    line-height: 1.6;
}

/* 团队网格 */
.team-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    max-width: 1000px;
    margin: 0 auto;
}

.team-member {
    text-align: center;
    padding: 2rem;
    background: var(--bg-secondary);
    border-radius: 15px;
    transition: transform 0.3s ease;
}

.team-member:hover {
    transform: translateY(-5px);
}

.team-member img {
    width: 120px;
    height: 120px;
    border-radius: 50%;
    margin-bottom: 1rem;
    object-fit: cover;
}

.team-member h4 {
    color: var(--text-primary);
    margin-bottom: 1rem;
    font-weight: 600;
}

.team-member p {
    color: var(--text-secondary);
    line-height: 1.6;
}

/* 企业文化价值观 */
.culture-values {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    max-width: 1000px;
    margin: 0 auto;
}

.value-item {
    text-align: center;
    padding: 2rem;
    background: linear-gradient(135deg, var(--bg-secondary) 0%, var(--bg-tertiary) 100%);
    border-radius: 15px;
    transition: transform 0.3s ease;
}

.value-item:hover {
    transform: translateY(-5px);
}

.value-icon {
    font-size: 3rem;
    margin-bottom: 1rem;
    color: var(--accent-primary);
}

.value-icon i {
    display: block;
}

.value-item h4 {
    color: var(--text-primary);
    margin-bottom: 1rem;
    font-weight: 600;
}

.value-item p {
    color: var(--text-secondary);
    line-height: 1.6;
}

/* 服务区域 */
.services-section {
    padding: 100px 0;
    background: linear-gradient(135deg, var(--bg-secondary) 0%, var(--bg-tertiary) 100%);
}

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

.service-card {
    background: var(--card-bg);
    padding: 2.5rem;
    border-radius: 15px;
    box-shadow: 0 10px 30px var(--shadow-light);
    transition: all 0.3s ease;
    position: relative;
    overflow: hidden;
}

.service-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 4px;
    background: linear-gradient(135deg, #2563eb, #1d4ed8);
}

.service-card:hover {
    transform: translateY(-10px);
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.15);
}

.service-icon {
    font-size: 3rem;
    margin-bottom: 1.5rem;
    color: var(--accent-primary);
}

.service-icon i {
    display: block;
}

.service-card h3 {
    color: var(--text-primary);
    margin-bottom: 1rem;
    font-weight: 600;
    font-size: 1.3rem;
}

.service-card p {
    color: var(--text-secondary);
    margin-bottom: 1.5rem;
    line-height: 1.6;
}

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

.service-card li {
    color: var(--text-secondary);
    margin-bottom: 0.5rem;
    position: relative;
    padding-left: 1.5rem;
}

.service-card li::before {
    content: '✓';
    position: absolute;
    left: 0;
    color: var(--accent-primary);
    font-weight: bold;
}

/* 联系我们区域 */
.contact-section {
    padding: 100px 0;
    background: var(--bg-primary);
}

.contact-content {
    max-width: 800px;
    margin: 0 auto;
}

.contact-info-centered {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    justify-items: center;
}

.contact-info {
    display: flex;
    flex-direction: column;
    gap: 2rem;
}

.contact-item {
    display: flex;
    align-items: center;
    gap: 1rem;
    padding: 1.5rem;
    background: var(--bg-secondary);
    border-radius: 10px;
    transition: transform 0.3s ease;
}

.contact-item:hover {
    transform: translateX(5px);
}

.contact-icon {
    font-size: 2rem;
    min-width: 50px;
    color: var(--accent-primary);
    display: flex;
    align-items: center;
    justify-content: center;
}

.contact-details h4 {
    color: var(--text-primary);
    margin-bottom: 0.5rem;
    font-weight: 600;
}

.contact-details p {
    color: var(--text-secondary);
}



/* 页脚样式 */
.footer {
    background: linear-gradient(135deg, #1e293b 0%, #334155 100%);
    color: white;
    padding: 60px 0 20px;
}

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

.footer-logo {
    display: flex;
    flex-direction: column;
    align-items: flex-start;
    gap: 12px;
    margin-bottom: 1rem;
}

.footer-logo-img {
    height: 40px;
    width: auto;
    flex-shrink: 0;
    align-self: flex-start;
}

.footer-logo-text {
    display: flex;
    flex-direction: column;
    line-height: 1;
    align-items: flex-start;
}

.footer-logo h3 {
    margin: 0;
    line-height: 1;
}

.footer-logo-subtitle {
    color: rgba(203, 213, 225, 0.8);
    font-size: 0.8rem;
    font-weight: 400;
    margin-top: 3px;
    letter-spacing: 0.5px;
}

.footer-section:first-child {
    max-width: 400px;
}

.footer-section h3,
.footer-section h4 {
    margin-bottom: 1rem;
    color: white;
}

.footer-section h3 {
    font-size: 1.5rem;
    color: #60a5fa;
}

.footer-section p {
    color: #cbd5e1;
    margin-bottom: 0.5rem;
}

.footer-section p i {
    margin-right: 8px;
    color: #60a5fa;
    width: 16px;
    text-align: center;
}

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

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

.footer-section ul li a {
    color: #cbd5e1;
    text-decoration: none;
    transition: color 0.3s ease;
}

.footer-section ul li a:hover {
    color: #60a5fa;
}

.footer-bottom {
    text-align: center;
    padding-top: 2rem;
    border-top: 1px solid #475569;
    color: #cbd5e1;
}

.copyright-info {
    margin-bottom: 1rem;
}

.filing-info {
    margin-top: 1rem;
}

.filing-links {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 2rem;
    flex-wrap: wrap;
}

.icp-link,
.police-link {
    display: flex;
    align-items: center;
    gap: 6px;
    color: #cbd5e1;
    text-decoration: none;
    font-size: 0.85rem;
    transition: all 0.3s ease;
    padding: 4px 8px;
    border-radius: 4px;
}

.icp-link:hover,
.police-link:hover {
    color: #60a5fa;
    background: rgba(96, 165, 250, 0.1);
}

.icp-link i {
    font-size: 0.9rem;
    color: #60a5fa;
}

.police-icon {
    width: 16px;
    height: 16px;
    object-fit: contain;
}

/* 移动端备案信息样式 */
@media screen and (max-width: 768px) {
    .filing-links {
        flex-direction: column;
        gap: 0.8rem;
    }

    .icp-link,
    .police-link {
        font-size: 0.8rem;
    }
}

.social-links {
    display: flex;
    flex-direction: column;
    gap: 0.8rem;
}

.social-link {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 8px 16px;
    background: rgba(96, 165, 250, 0.2);
    color: #60a5fa;
    text-decoration: none;
    border-radius: 20px;
    transition: all 0.3s ease;
    width: fit-content;
}

.social-link i {
    font-size: 1.1rem;
    width: 16px;
    text-align: center;
}

.social-link:hover {
    background: #60a5fa;
    color: white;
    transform: translateX(5px);
}

/* 微信二维码气泡框 */
.wechat-link {
    position: relative;
}

.wechat-qr-popup {
    position: absolute;
    bottom: 100%;
    left: 50%;
    transform: translateX(-50%);
    background: white;
    border-radius: 12px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.3);
    padding: 20px;
    width: 220px;
    opacity: 0;
    visibility: hidden;
    transition: all 0.3s ease;
    z-index: 1000;
    margin-bottom: 10px;
}

.wechat-qr-popup.show {
    opacity: 1;
    visibility: visible;
    transform: translateX(-50%) translateY(-10px);
}

.wechat-qr-popup::after {
    content: '';
    position: absolute;
    top: 100%;
    left: 50%;
    transform: translateX(-50%);
    border: 8px solid transparent;
    border-top-color: white;
}

.qr-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 15px;
    padding-bottom: 10px;
    border-bottom: 1px solid #e2e8f0;
}

.qr-header h4 {
    color: #1e293b;
    font-size: 1rem;
    margin: 0;
}

.close-btn {
    background: none;
    border: none;
    font-size: 1.5rem;
    color: #64748b;
    cursor: pointer;
    padding: 0;
    width: 24px;
    height: 24px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 50%;
    transition: all 0.2s ease;
}

.close-btn:hover {
    background: #f1f5f9;
    color: #1e293b;
}

.qr-code {
    text-align: center;
    margin-bottom: 15px;
}

.qr-code img {
    width: 120px;
    height: 120px;
    border-radius: 8px;
    border: 1px solid #e2e8f0;
}

.wechat-qr-popup p {
    text-align: center;
    color: #64748b;
    font-size: 0.85rem;
    margin: 0;
    line-height: 1.4;
}

/* 暗黑模式下的气泡框 */
[data-theme="dark"] .wechat-qr-popup {
    background: var(--bg-secondary);
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.5);
}

[data-theme="dark"] .wechat-qr-popup::after {
    border-top-color: var(--bg-secondary);
}

[data-theme="dark"] .qr-header {
    border-bottom-color: var(--border-color);
}

[data-theme="dark"] .qr-header h4 {
    color: var(--text-primary);
}

[data-theme="dark"] .close-btn {
    color: var(--text-secondary);
}

[data-theme="dark"] .close-btn:hover {
    background: var(--bg-tertiary);
    color: var(--text-primary);
}

[data-theme="dark"] .wechat-qr-popup p {
    color: var(--text-secondary);
}

/* 返回顶部按钮 */
.back-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 50px;
    height: 50px;
    background: var(--accent-primary);
    color: var(--text-light);
    border: none;
    border-radius: 50%;
    font-size: 1.5rem;
    cursor: pointer;
    opacity: 0;
    visibility: hidden;
    transition: all 0.3s ease;
    z-index: 1000;
}

.back-to-top.show {
    opacity: 1;
    visibility: visible;
}

.back-to-top:hover {
    background: var(--accent-secondary);
    transform: translateY(-3px);
}

/* 响应式设计 - 平板设备 */
@media screen and (max-width: 768px) {
    .container {
        padding: 0 15px;
    }

    .nav-container {
        padding: 1rem 15px;
    }

    .logo-img {
        height: 35px;
    }

    .nav-logo h2 {
        font-size: 1.5rem;
    }

    .logo-subtitle {
        font-size: 0.6rem;
    }

    .nav-menu {
        position: fixed;
        left: -100%;
        top: 70px;
        flex-direction: column;
        background-color: var(--navbar-bg);
        backdrop-filter: blur(20px);
        -webkit-backdrop-filter: blur(20px);
        width: 100%;
        text-align: center;
        transition: 0.3s;
        box-shadow: 0 10px 27px var(--shadow-light);
        border-top: 1px solid var(--border-color);
        padding: 2rem 0;
    }

    .nav-menu.active {
        left: 0;
    }

    .nav-menu.active .nav-link {
        color: #333;
        text-shadow: none;
    }

    .nav-menu.active .nav-link:hover {
        color: var(--accent-primary);
    }

    .nav-menu.active .theme-toggle {
        border-color: var(--text-primary);
        margin: 1rem auto 0;
    }

    /* 暗黑模式下的移动端菜单 */
    [data-theme="dark"] .nav-menu.active {
        background-color: rgba(15, 23, 42, 0.95);
        border-top: 1px solid rgba(255, 255, 255, 0.1);
    }

    [data-theme="dark"] .nav-menu.active .nav-link {
        color: var(--text-primary);
    }

    [data-theme="dark"] .nav-menu.active .nav-link:hover {
        color: var(--accent-secondary);
    }

    .nav-toggle {
        display: flex;
    }

    .nav-toggle.active .bar:nth-child(2) {
        opacity: 0;
    }

    .nav-toggle.active .bar:nth-child(1) {
        transform: translateY(8px) rotate(45deg);
    }

    .nav-toggle.active .bar:nth-child(3) {
        transform: translateY(-8px) rotate(-45deg);
    }

    .slide-content h1 {
        font-size: 2.5rem;
    }

    .slide-content p {
        font-size: 1.2rem;
    }

    .intro-content {
        grid-template-columns: 1fr;
        gap: 2rem;
        text-align: center;
    }

    .intro-stats {
        justify-content: center;
    }

    .about-tabs {
        flex-direction: column;
        align-items: center;
    }

    /* 移动端使用简单的卡片式布局 */
    .timeline {
        max-width: 100%;
        padding: 0;
        margin: 0;
    }

    .timeline::before {
        display: none;
    }

    .timeline-item {
        flex-direction: column !important;
        padding: 0;
        margin-bottom: 1.5rem;
        position: relative;
        background: var(--bg-secondary);
        border-radius: 12px;
        overflow: hidden;
        box-shadow: 0 4px 15px var(--shadow-light);
    }

    .timeline-year {
        position: static;
        background: var(--accent-primary);
        color: var(--text-light);
        margin: 0;
        padding: 12px 20px;
        font-size: 1rem;
        font-weight: 700;
        text-align: left;
        min-width: auto;
        border-radius: 0;
    }

    .timeline-content {
        margin: 0;
        padding: 1.5rem;
        width: 100%;
        background: var(--card-bg);
    }

    .services-grid {
        grid-template-columns: 1fr;
    }

    .contact-info-centered {
        grid-template-columns: 1fr;
        gap: 1.5rem;
    }

    .footer-content {
        grid-template-columns: 1fr;
        text-align: center;
    }

    .social-links {
        justify-content: center;
    }
}

/* 响应式设计 - 手机设备 */
@media screen and (max-width: 480px) {
    .slide-content h1 {
        font-size: 2rem;
    }

    .slide-content p {
        font-size: 1rem;
    }

    .logo-img {
        height: 30px;
    }

    .nav-logo h2 {
        font-size: 1.3rem;
    }

    .logo-subtitle {
        font-size: 0.55rem;
    }

    .cta-button {
        padding: 12px 24px;
        font-size: 0.9rem;
    }

    .section-header h2 {
        font-size: 2rem;
    }

    .intro-text h2 {
        font-size: 2rem;
    }

    .intro-stats {
        flex-direction: column;
        gap: 1rem;
    }

    .stat-item h3 {
        font-size: 2rem;
    }

    .about-tabs {
        gap: 0.5rem;
    }

    .tab-button {
        padding: 10px 16px;
        font-size: 0.9rem;
    }

    .team-grid {
        grid-template-columns: 1fr;
    }

    .culture-values {
        grid-template-columns: 1fr;
    }

    /* 手机端时间线卡片式布局优化 */
    .timeline {
        padding: 0;
        margin: 0;
    }

    .timeline::before {
        display: none;
    }

    .timeline-item {
        margin-bottom: 1rem;
        border-radius: 10px;
    }

    .timeline-year {
        padding: 10px 15px;
        font-size: 0.9rem;
        font-weight: 600;
    }

    .timeline-content {
        padding: 1rem;
        font-size: 0.9rem;
    }

    .timeline-content h3 {
        font-size: 1rem;
        margin-bottom: 0.5rem;
    }

    .timeline-content p {
        font-size: 0.85rem;
        line-height: 1.5;
    }



    .slider-controls {
        padding: 0 1rem;
    }

    .prev-btn, .next-btn {
        font-size: 1.5rem;
        padding: 8px 12px;
    }
}

/* 动画效果 */
@keyframes slideInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes slideInLeft {
    from {
        opacity: 0;
        transform: translateX(-30px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

@keyframes slideInRight {
    from {
        opacity: 0;
        transform: translateX(30px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

/* 滚动动画类 - 修复：默认可见 */
.animate-on-scroll {
    opacity: 1;
    transform: translateY(0);
    transition: all 0.6s ease;
}

.animate-on-scroll.animated {
    opacity: 1;
    transform: translateY(0);
}