/* ===================================
   非洲 ECTN 检测认证中心 - 现代化样式
   支持 PC 和移动端访问
   =================================== */

/* CSS 变量定义 */
:root {
    --primary-color: #1a56db;
    --primary-dark: #1e40af;
    --primary-light: #3b82f6;
    --secondary-color: #0ea5e9;
    --accent-color: #f59e0b;
    --text-primary: #1f2937;
    --text-secondary: #4b5563;
    --text-light: #6b7280;
    --bg-primary: #ffffff;
    --bg-secondary: #f9fafb;
    --bg-dark: #111827;
    --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), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
    --transition: all 0.3s ease;
    --border-radius: 8px;
    --border-radius-lg: 16px;
}

/* 基础重置 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
    -webkit-text-size-adjust: 100%;
    -ms-text-size-adjust: 100%;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', sans-serif;
    line-height: 1.6;
    color: var(--text-primary);
    background-color: var(--bg-primary);
    overflow-x: hidden;
    -webkit-tap-highlight-color: transparent;
}

/* 触摸优化 */
@media (hover: none) and (pointer: coarse) {
    .btn, .nav-link, .service-link, .contact-item {
        min-height: 44px;
    }
    
    .service-card:hover {
        transform: none;
    }
    
    .news-card:hover {
        transform: none;
    }
}

a {
    text-decoration: none;
    color: inherit;
    transition: var(--transition);
}

ul {
    list-style: none;
}

img {
    max-width: 100%;
    height: auto;
    display: block;
}

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

/* 按钮样式 */
.btn {
    display: inline-block;
    padding: 12px 28px;
    font-size: 16px;
    font-weight: 500;
    border-radius: var(--border-radius);
    cursor: pointer;
    transition: var(--transition);
    border: none;
    text-align: center;
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary-color), var(--primary-dark));
    color: white;
    box-shadow: 0 4px 14px rgba(26, 86, 219, 0.4);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(26, 86, 219, 0.5);
}

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

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

.btn-block {
    width: 100%;
}

/* 头部导航 */
.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
}

.header.scrolled {
    box-shadow: var(--shadow-md);
}

.header .container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding-top: 15px;
    padding-bottom: 15px;
}

.logo a {
    display: flex;
    align-items: center;
    gap: 10px;
}

.logo-icon {
    font-size: 32px;
    color: var(--primary-color);
}

.logo-text {
    font-size: 22px;
    font-weight: 700;
    color: var(--text-primary);
}

.nav-list {
    display: flex;
    gap: 35px;
}

.nav-link {
    font-size: 15px;
    font-weight: 500;
    color: var(--text-secondary);
    position: relative;
    padding: 5px 0;
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--primary-color);
    transition: var(--transition);
}

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

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


/* 多语言文本换行处理 */
[data-i18n] {
    overflow-wrap: break-word;
    word-wrap: break-word;
    hyphens: auto;
}

.nav-link {
    white-space: nowrap;
}

/* 语言切换器 */
.language-switcher {
    position: relative;
    margin-right: 15px;
}

.lang-btn {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 10px 15px;
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    cursor: pointer;
    transition: var(--transition);
    font-size: 14px;
    color: var(--text-secondary);
}

.lang-btn:hover,
.lang-btn.active {
    background: rgba(26, 86, 219, 0.1);
    border-color: var(--primary-color);
    color: var(--primary-color);
}

.lang-btn i:first-child {
    font-size: 16px;
}

.lang-btn .current-lang {
    font-weight: 500;
}

.lang-btn i:last-child {
    font-size: 12px;
    transition: transform 0.3s ease;
}

.lang-btn.active i:last-child {
    transform: rotate(180deg);
}

.lang-dropdown {
    position: absolute;
    top: calc(100% + 8px);
    right: 0;
    background: white;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-xl);
    padding: 8px;
    min-width: 160px;
    opacity: 0;
    visibility: hidden;
    transform: translateY(-10px);
    transition: var(--transition);
    z-index: 1001;
}

.lang-dropdown.show {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.lang-option {
    display: flex;
    align-items: center;
    gap: 10px;
    width: 100%;
    padding: 10px 12px;
    background: none;
    border: none;
    border-radius: var(--border-radius);
    cursor: pointer;
    transition: var(--transition);
    text-align: left;
    font-size: 14px;
    color: var(--text-secondary);
}

.lang-option:hover {
    background: var(--bg-secondary);
    color: var(--primary-color);
}

.lang-flag {
    font-size: 18px;
}

.lang-name {
    font-weight: 500;
}

.header-actions {
    display: flex;
    align-items: center;
    gap: 20px;
}

.phone-btn {
    display: flex;
    align-items: center;
    gap: 8px;
    color: var(--primary-color);
    font-weight: 600;
    padding: 10px 20px;
    background: rgba(26, 86, 219, 0.1);
    border-radius: var(--border-radius);
    transition: var(--transition);
}

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

.mobile-menu-btn {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 5px;
}

.mobile-menu-btn span {
    width: 25px;
    height: 3px;
    background: var(--text-primary);
    border-radius: 2px;
    transition: var(--transition);
}

/* 移动端菜单 */
.mobile-menu {
    display: none;
    position: fixed;
    top: 70px;
    left: 0;
    right: 0;
    background: white;
    box-shadow: var(--shadow-lg);
    z-index: 999;
    padding: 20px;
}

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

.mobile-nav-list {
    display: flex;
    flex-direction: column;
    gap: 15px;
}

.mobile-nav-link {
    display: block;
    padding: 12px 15px;
    border-radius: var(--border-radius);
    font-weight: 500;
    color: var(--text-secondary);
    transition: var(--transition);
}

.mobile-nav-link:hover {
    background: var(--bg-secondary);
    color: var(--primary-color);
}

/* 主横幅区域 */
.hero {
    position: relative;
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
    background: linear-gradient(135deg, #1a56db 0%, #0ea5e9 100%);
}

.hero-bg {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 100"><circle cx="50" cy="50" r="40" fill="none" stroke="rgba(255,255,255,0.1)" stroke-width="0.5"/><circle cx="50" cy="50" r="30" fill="none" stroke="rgba(255,255,255,0.1)" stroke-width="0.5"/><circle cx="50" cy="50" r="20" fill="none" stroke="rgba(255,255,255,0.1)" stroke-width="0.5"/></svg>');
    background-size: 100px 100px;
    animation: bgRotate 60s linear infinite;
}

@keyframes bgRotate {
    from { transform: rotate(0deg); }
    to { transform: rotate(360deg); }
}

.hero-overlay {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(180deg, rgba(26, 86, 219, 0.8) 0%, rgba(14, 165, 233, 0.7) 100%);
}

.hero-content {
    position: relative;
    z-index: 1;
    text-align: center;
    color: white;
    padding: 100px 20px 60px;
}

.hero-title {
    font-size: clamp(32px, 5vw, 56px);
    font-weight: 800;
    margin-bottom: 20px;
    line-height: 1.2;
}

.hero-title .highlight {
    background: linear-gradient(135deg, #fbbf24, #f59e0b);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-subtitle {
    font-size: clamp(16px, 2vw, 20px);
    max-width: 700px;
    margin: 0 auto 40px;
    opacity: 0.95;
}

.hero-buttons {
    display: flex;
    gap: 20px;
    justify-content: center;
    flex-wrap: wrap;
    margin-bottom: 60px;
}

.hero-buttons .btn-primary {
    background: white;
    color: var(--primary-color);
    box-shadow: 0 4px 14px rgba(255, 255, 255, 0.3);
}

.hero-buttons .btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(255, 255, 255, 0.4);
}

.hero-buttons .btn-outline {
    border-color: white;
    color: white;
}

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

.hero-stats {
    display: flex;
    justify-content: center;
    gap: 50px;
    flex-wrap: wrap;
}

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

.stat-number {
    display: block;
    font-size: 48px;
    font-weight: 800;
    color: white;
}

.stat-label {
    display: block;
    font-size: 14px;
    opacity: 0.9;
    margin-top: 5px;
}

.hero-scroll {
    position: absolute;
    bottom: 30px;
    left: 50%;
    transform: translateX(-50%);
    z-index: 1;
}

.scroll-down {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 50px;
    height: 50px;
    border: 2px solid rgba(255, 255, 255, 0.3);
    border-radius: 50%;
    color: white;
    font-size: 20px;
    animation: bounce 2s infinite;
}

@keyframes bounce {
    0%, 20%, 50%, 80%, 100% { transform: translateY(0); }
    40% { transform: translateY(-10px); }
    60% { transform: translateY(-5px); }
}

/* 动画效果 */
.fade-in-up {
    opacity: 0;
    transform: translateY(30px);
    animation: fadeInUp 0.8s ease forwards;
}

@keyframes fadeInUp {
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* 通用区块样式 */
section {
    padding: 100px 0;
}

.section-header {
    text-align: center;
    margin-bottom: 60px;
}

.section-header.text-left {
    text-align: left;
}

.section-title {
    font-size: clamp(28px, 4vw, 42px);
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 15px;
}

.section-subtitle {
    font-size: 16px;
    color: var(--text-secondary);
    max-width: 600px;
    margin: 0 auto;
}

/* 服务项目 */
.services {
    background: var(--bg-secondary);
}

.services-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 30px;
}

.service-card {
    background: white;
    border-radius: var(--border-radius-lg);
    padding: 35px;
    box-shadow: var(--shadow-md);
    transition: var(--transition);
    border: 1px solid var(--border-color);
}

/* 法文长文本处理 */
.service-desc, .about-text p, [data-i18n*='desc'] {
    overflow-wrap: break-word;
    word-wrap: break-word;
    hyphens: auto;
    text-align: justify;
}



.service-card:hover {
    transform: translateY(-10px);
    box-shadow: var(--shadow-xl);
    border-color: var(--primary-light);
}

.service-icon {
    width: 70px;
    height: 70px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    border-radius: var(--border-radius-lg);
    font-size: 32px;
    color: white;
    margin-bottom: 25px;
}

.service-title {
    font-size: 22px;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 15px;
}

.service-desc {
    color: var(--text-secondary);
    margin-bottom: 20px;
    line-height: 1.7;
}

.service-list {
    margin-bottom: 25px;
}

.service-list li {
    display: flex;
    align-items: center;
    gap: 10px;
    color: var(--text-secondary);
    margin-bottom: 10px;
    font-size: 14px;
}

.service-list i {
    color: var(--primary-color);
    font-size: 12px;
}

.service-link {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    color: var(--primary-color);
    font-weight: 600;
    font-size: 15px;
}

.service-link:hover {
    gap: 12px;
}

/* 关于我们 */
.about-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: center;
}

.about-content .section-header {
    text-align: left;
    margin-bottom: 30px;
}

.about-text {
    color: var(--text-secondary);
    margin-bottom: 20px;
    line-height: 1.8;
}

.about-features {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 20px;
    margin: 30px 0;
}

.feature-item {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 15px;
    background: var(--bg-secondary);
    border-radius: var(--border-radius);
}

.feature-item i {
    font-size: 24px;
    color: var(--primary-color);
}

.feature-item span {
    font-weight: 500;
    color: var(--text-primary);
}

.about-image {
    position: relative;
}

.image-wrapper {
    border-radius: var(--border-radius-lg);
    overflow: hidden;
    box-shadow: var(--shadow-xl);
}

.placeholder-image {
    width: 100%;
    height: 400px;
    background: linear-gradient(135deg, var(--bg-secondary), var(--border-color));
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 15px;
    color: var(--text-light);
}

.placeholder-image i {
    font-size: 80px;
}

.placeholder-image span {
    font-size: 16px;
}

.about-badge {
    position: absolute;
    bottom: -20px;
    left: -20px;
    background: linear-gradient(135deg, var(--primary-color), var(--primary-dark));
    color: white;
    padding: 25px 35px;
    border-radius: var(--border-radius-lg);
    text-align: center;
    box-shadow: var(--shadow-lg);
}

.badge-number {
    display: block;
    font-size: 42px;
    font-weight: 800;
}

.badge-text {
    font-size: 14px;
    opacity: 0.9;
}

/* 认证流程 */
.process {
    background: var(--bg-dark);
    color: white;
}

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

.process .section-subtitle {
    color: rgba(255, 255, 255, 0.8);
}

.process-timeline {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 40px;
    position: relative;
    margin-top: 40px;
}

.process-timeline::before {
    content: '';
    position: absolute;
    top: 50px;
    left: 12.5%;
    right: 12.5%;
    height: 3px;
    background: linear-gradient(90deg, var(--primary-color), var(--secondary-color));
    opacity: 0.5;
}

.process-step {
    position: relative;
    text-align: center;
    padding: 0 15px;
}

.step-number {
    width: 100px;
    height: 100px;
    margin: 0 auto 30px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    border-radius: 50%;
    font-size: 32px;
    font-weight: 800;
    position: relative;
    z-index: 1;
    box-shadow: 0 10px 30px rgba(26, 86, 219, 0.4);
}

.step-content {
    background: rgba(255, 255, 255, 0.05);
    border-radius: 16px;
    padding: 25px 20px;
    border: 1px solid rgba(255, 255, 255, 0.1);
    transition: all 0.3s ease;
}

.step-content:hover {
    background: rgba(255, 255, 255, 0.08);
    transform: translateY(-5px);
}

.step-content h3 {
    font-size: 22px;
    margin-bottom: 12px;
    font-weight: 600;
    color: #fff;
}

.step-content p {
    color: rgba(255, 255, 255, 0.85);
    margin-bottom: 20px;
    font-size: 15px;
    line-height: 1.6;
}

.step-list {
    text-align: left;
    list-style: none;
    padding: 0;
    margin: 0;
}

.step-list li {
    color: rgba(255, 255, 255, 0.75);
    font-size: 14px;
    padding: 8px 0;
    padding-left: 24px;
    position: relative;
    line-height: 1.5;
}

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

/* 新闻资讯 */
.news-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 30px;
}

.news-card {
    background: white;
    border-radius: var(--border-radius-lg);
    overflow: hidden;
    box-shadow: var(--shadow-md);
    transition: var(--transition);
}

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

.news-image {
    position: relative;
    height: 200px;
    overflow: hidden;
}

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

.placeholder-news-image {
    width: 100%;
    height: 100%;
    background: linear-gradient(135deg, var(--primary-light), var(--secondary-color));
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 60px;
    color: rgba(255, 255, 255, 0.5);
}

.news-category {
    position: absolute;
    top: 15px;
    left: 15px;
    background: var(--accent-color);
    color: white;
    padding: 5px 15px;
    border-radius: 20px;
    font-size: 12px;
    font-weight: 600;
}

.news-content {
    padding: 25px;
}

.news-meta {
    margin-bottom: 10px;
}

.news-date {
    font-size: 13px;
    color: var(--text-light);
}

.news-title {
    font-size: 18px;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 12px;
    line-height: 1.4;
}

.news-excerpt {
    color: var(--text-secondary);
    font-size: 14px;
    line-height: 1.7;
    margin-bottom: 20px;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.news-link {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    color: var(--primary-color);
    font-weight: 600;
    font-size: 14px;
}

.news-link:hover {
    gap: 12px;
}

.news-more {
    text-align: center;
    margin-top: 50px;
}

/* 联系我们 */
.contact {
    background: var(--bg-secondary);
}

.contact-cards {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 30px;
    margin-top: 40px;
}

.contact-card {
    background: white;
    padding: 35px 25px;
    border-radius: var(--border-radius-lg);
    box-shadow: var(--shadow-md);
    text-align: center;
    transition: var(--transition);
    position: relative;
}

.contact-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-xl);
}

.contact-card.wechat-card {
    /* 和其他卡片样式一致，不使用特殊绿色 */
}

.contact-card.wechat-card h3,
.contact-card.wechat-card p,
.contact-card.wechat-card span {
    /* 继承默认颜色 */
}

.contact-card.wechat-card .contact-card-icon {
    background: rgba(26, 86, 219, 0.1);
    color: var(--primary-color);
}

.contact-card-icon {
    width: 70px;
    height: 70px;
    margin: 0 auto 20px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    border-radius: 50%;
    font-size: 28px;
    color: white;
}

.contact-card h3 {
    font-size: 18px;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 12px;
}

.contact-card .contact-value {
    font-size: 16px;
    color: var(--primary-color);
    font-weight: 500;
    margin-bottom: 8px;
    word-break: break-word;
}

.contact-card .contact-value a {
    color: var(--primary-color);
    text-decoration: none;
}

.contact-card .contact-value a:hover {
    text-decoration: underline;
}

.contact-card .contact-time {
    font-size: 13px;
    color: var(--text-light);
}

.wechat-qrcode {
    margin-top: 20px;
    display: flex;
    justify-content: center;
    align-items: center;
}

.qrcode-image {
    width: 150px;
    height: 150px;
    object-fit: contain;
    border-radius: 12px;
    background: white;
    padding: 8px;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.08);
}

/* 页脚 */
.footer {
    background: var(--bg-dark);
    color: rgba(255, 255, 255, 0.7);
    padding: 70px 0 30px;
}

.footer-grid {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1.5fr;
    gap: 50px;
    margin-bottom: 50px;
}

.footer-logo {
    display: flex;
    align-items: center;
    gap: 10px;
    margin-bottom: 20px;
}

.footer-logo .logo-icon {
    color: var(--primary-light);
}

.footer-logo .logo-text {
    color: white;
}

.footer-about p {
    line-height: 1.8;
    margin-bottom: 20px;
}

.footer-social {
    display: flex;
    gap: 15px;
}

.footer-social a {
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 50%;
    color: white;
    font-size: 18px;
    transition: var(--transition);
}

.footer-social a:hover {
    background: var(--primary-color);
    transform: translateY(-3px);
}

.footer-links h4,
.footer-contact h4 {
    color: white;
    font-size: 18px;
    margin-bottom: 25px;
}

.footer-links ul,
.footer-contact ul {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.footer-links a {
    color: rgba(255, 255, 255, 0.7);
    font-size: 14px;
    transition: var(--transition);
}

.footer-links a:hover {
    color: var(--primary-light);
    padding-left: 5px;
}

.footer-contact li {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 14px;
}

.footer-contact i {
    color: var(--primary-light);
    width: 20px;
}

.footer-bottom {
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    padding-top: 30px;
    text-align: center;
}

.footer-bottom p {
    font-size: 14px;
    margin-bottom: 10px;
}

.footer-bottom a {
    color: rgba(255, 255, 255, 0.7);
    transition: var(--transition);
}

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

/* 回到顶部按钮 */
.back-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 50px;
    height: 50px;
    background: linear-gradient(135deg, var(--primary-color), var(--primary-dark));
    color: white;
    border: none;
    border-radius: 50%;
    cursor: pointer;
    box-shadow: var(--shadow-lg);
    opacity: 0;
    visibility: hidden;
    transition: var(--transition);
    z-index: 999;
}

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

.back-to-top:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-xl);
}

/* 响应式设计 - 平板 */
@media (max-width: 1024px) {
    .process-timeline {
        grid-template-columns: repeat(2, 1fr);
        gap: 30px;
    }

    .process-timeline::before {
        display: none;
    }

    .step-number {
        width: 80px;
        height: 80px;
        font-size: 28px;
    }

    .step-content {
        padding: 20px 15px;
    }

    .step-content h3 {
        font-size: 20px;
    }

    .footer-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .container {
        padding: 0 15px;
    }

    .contact-cards {
        grid-template-columns: repeat(2, 1fr);
        gap: 20px;
    }

    .contact-card {
        padding: 25px 20px;
    }

    .contact-card-icon {
        width: 60px;
        height: 60px;
        font-size: 24px;
    }
    }

/* 响应式设计 - 手机横屏和小平板 */
@media (max-width: 768px) {
    .nav {
        display: none;
    }
    
    .header-actions .phone-btn {
        display: none;
    }
    
    /* 移动端语言切换器优化 */
    .language-switcher {
        margin-right: 10px;
    }
    
    .lang-btn {
        padding: 8px 12px;
    }
    
    .lang-btn .current-lang {
        display: none;
    }
    
    .lang-dropdown {
        right: auto;
        left: 0;
    }
    
    .mobile-menu-btn {
        display: flex;
    }
    
    .about-grid,
    .contact-cards {
        grid-template-columns: 1fr;
        gap: 40px;
    }
    
    .about-features {
        grid-template-columns: 1fr;
    }
    
    .about-badge {
        position: relative;
        bottom: auto;
        left: auto;
        margin-top: 30px;
        display: inline-block;
    }
    
    .process-timeline {
        grid-template-columns: 1fr;
        gap: 25px;
    }

    .step-number {
        width: 70px;
        height: 70px;
        font-size: 24px;
        margin-bottom: 20px;
    }

    .step-content {
        padding: 20px;
    }

    .step-content h3 {
        font-size: 18px;
    }

    .step-content p {
        font-size: 14px;
    }
    
    .hero-stats {
        gap: 25px;
    }
    
    .stat-number {
        font-size: 32px;
    }
    
    .stat-label {
        font-size: 13px;
    }
    
    .footer-grid {
        grid-template-columns: 1fr;
        gap: 30px;
    }
    
    section {
        padding: 60px 0;
    }
    
    .section-title {
        font-size: 28px;
    }
    
    .service-card {
        padding: 25px;
    }

    .contact-cards {
        grid-template-columns: 1fr;
        gap: 15px;
    }

    .contact-card {
        padding: 20px 15px;
    }

    .contact-card-icon {
        width: 50px;
        height: 50px;
        font-size: 20px;
    }

    .contact-card h3 {
        font-size: 16px;
    }

    .contact-card .contact-value {
        font-size: 14px;
    }

    .qrcode-placeholder {
        width: 120px;
        height: 120px;
    }

    .qrcode-placeholder i {
        font-size: 32px;
    }
    }

/* 响应式设计 - 手机竖屏 */
@media (max-width: 480px) {
    .hero-buttons {
        flex-direction: column;
        align-items: center;
    }
    
    .hero-buttons .btn {
        width: 100%;
        max-width: 280px;
    }
    
    .services-grid,
    .news-grid {
        grid-template-columns: 1fr;
    }
    
    .contact-form-wrapper {
        padding: 20px;
    }
    
    .hero-title {
        font-size: 28px;
    }
    
    .hero-subtitle {
        font-size: 15px;
    }
    
    .hero-stats {
        gap: 20px;
    }
    
    .stat-item {
        min-width: 80px;
    }
    
    .stat-number {
        font-size: 28px;
    }
    
    .stat-label {
        font-size: 12px;
    }
    
    .contact-item {
        flex-direction: column;
        text-align: center;
        padding: 20px;
    }
    
    .contact-icon {
        margin: 0 auto;
    }
    
    .footer {
        padding: 50px 0 20px;
    }
    
    .back-to-top {
        bottom: 20px;
        right: 20px;
        width: 45px;
        height: 45px;
    }
}

/* 超小屏幕优化 */
@media (max-width: 375px) {
    .hero-title {
        font-size: 24px;
    }
    
    .section-title {
        font-size: 24px;
    }
    
    .service-title {
        font-size: 18px;
    }
    
    .container {
        padding: 0 12px;
    }
}

/* 打印样式 */
@media print {
    .header,
    .mobile-menu,
    .hero-scroll,
    .back-to-top,
    .contact-form-wrapper {
        display: none !important;
    }
}
/* 屏幕阅读器专用样式 */
.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

/* 跳转到主要内容链接 */
.skip-link {
    position: absolute;
    top: -40px;
    left: 6px;
    background: #1a56db;
    color: white;
    padding: 8px 12px;
    text-decoration: none;
    border-radius: 4px;
    z-index: 1000;
}

.skip-link:focus {
    top: 6px;
}