/* 全局重置与基础样式 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}
html {
    scroll-behavior: smooth;
}
body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: #f8f9fa;
    color: #333;
    line-height: 1.8;
    overflow-x: hidden;
    transition: background 0.3s, color 0.3s;
}
body.dark-mode {
    background: #0f0f1a;
    color: #e0e0e0;
}
.container {
    max-width: 1280px;
    margin: 0 auto;
    padding: 0 20px;
}
section, header, footer, nav, main, article, aside {
    display: block;
}
a {
    text-decoration: none;
    color: inherit;
    transition: color 0.3s;
}
img, svg {
    max-width: 100%;
    height: auto;
    display: block;
}
ul {
    list-style: none;
}

/* 渐变文字 */
.gradient-text {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

/* 毛玻璃卡片 */
.glass-card {
    background: rgba(255,255,255,0.7);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-radius: 20px;
    border: 1px solid rgba(255,255,255,0.3);
    box-shadow: 0 8px 32px rgba(0,0,0,0.1);
    transition: transform 0.3s, box-shadow 0.3s;
}
.dark-mode .glass-card {
    background: rgba(20,20,40,0.7);
    border-color: rgba(255,255,255,0.1);
    box-shadow: 0 8px 32px rgba(0,0,0,0.5);
}
.glass-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 12px 40px rgba(0,0,0,0.15);
}
.dark-mode .glass-card:hover {
    box-shadow: 0 12px 40px rgba(0,0,0,0.6);
}

/* 圆角卡片 */
.rounded-card {
    border-radius: 24px;
    overflow: hidden;
    box-shadow: 0 4px 20px rgba(0,0,0,0.08);
    transition: all 0.3s;
}
.rounded-card:hover {
    box-shadow: 0 8px 40px rgba(0,0,0,0.12);
    transform: translateY(-3px);
}
.dark-mode .rounded-card {
    background: #1a1a2e;
    box-shadow: 0 4px 20px rgba(0,0,0,0.3);
}

/* 阴影提升 */
.shadow-elevated {
    box-shadow: 0 10px 40px rgba(0,0,0,0.1);
}

/* 主按钮 */
.btn-primary {
    display: inline-block;
    padding: 14px 36px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: #fff;
    border-radius: 50px;
    font-weight: 600;
    transition: transform 0.3s, box-shadow 0.3s;
    border: none;
    cursor: pointer;
    text-align: center;
}
.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 24px rgba(102,126,234,0.4);
}

/* 标题 */
.section-title {
    font-size: 2.2rem;
    font-weight: 700;
    margin-bottom: 20px;
    text-align: center;
}
.section-subtitle {
    text-align: center;
    max-width: 700px;
    margin: 0 auto 50px;
    color: #666;
    font-size: 1.1rem;
}
.dark-mode .section-subtitle {
    color: #aaa;
}

/* 网格布局 */
.grid-2 {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 40px;
}
.grid-3 {
    display: grid;
    grid-template-columns: 1fr 1fr 1fr;
    gap: 30px;
}
.grid-4 {
    display: grid;
    grid-template-columns: 1fr 1fr 1fr 1fr;
    gap: 24px;
}

/* 工具类 */
.flex-center {
    display: flex;
    align-items: center;
    justify-content: center;
}
.text-center {
    text-align: center;
}
.text-left {
    text-align: left;
}
.mt-20 { margin-top: 20px; }
.mt-40 { margin-top: 40px; }
.mb-20 { margin-bottom: 20px; }
.mb-40 { margin-bottom: 40px; }
.py-20 { padding: 40px 0; }
.py-40 { padding: 80px 0; }
.p-8 { padding: 40px; }

/* 淡入动画 */
.fade-in {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}
.fade-in.visible {
    opacity: 1;
    transform: translateY(0);
}

/* ========== Header ========== */
header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background: rgba(255,255,255,0.9);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-bottom: 1px solid rgba(0,0,0,0.05);
    transition: background 0.3s;
}
.dark-mode header {
    background: rgba(15,15,26,0.9);
    border-color: rgba(255,255,255,0.05);
}
.header-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 12px 20px;
    max-width: 1280px;
    margin: 0 auto;
}
.logo svg {
    height: 40px;
    width: auto;
}
nav ul {
    display: flex;
    list-style: none;
    gap: 32px;
}
nav ul li a {
    font-weight: 500;
    font-size: 0.95rem;
    padding: 8px 0;
    position: relative;
    transition: color 0.3s;
}
nav ul li a::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background: linear-gradient(135deg, #667eea, #764ba2);
    transition: width 0.3s;
}
nav ul li a:hover::after,
nav ul li a.active::after {
    width: 100%;
}
nav ul li a:hover,
nav ul li a.active {
    color: #667eea;
}
.nav-actions {
    display: flex;
    align-items: center;
    gap: 16px;
}
.dark-mode-toggle {
    background: none;
    border: none;
    cursor: pointer;
    font-size: 1.4rem;
    padding: 4px;
    border-radius: 50%;
    transition: background 0.3s, transform 0.3s;
}
.dark-mode-toggle:hover {
    background: rgba(0,0,0,0.05);
    transform: scale(1.1);
}
.dark-mode .dark-mode-toggle:hover {
    background: rgba(255,255,255,0.1);
}
.mobile-menu-btn {
    display: none;
    background: none;
    border: none;
    font-size: 1.8rem;
    cursor: pointer;
    color: inherit;
    transition: transform 0.3s;
}
.mobile-menu-btn:hover {
    transform: scale(1.1);
}

/* ========== Hero ========== */
.hero {
    padding: 140px 0 80px;
    background: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
    position: relative;
    overflow: hidden;
}
.dark-mode .hero {
    background: linear-gradient(135deg, #0f0f1a 0%, #1a1a2e 100%);
}
.hero::before {
    content: '';
    position: absolute;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background: radial-gradient(circle at 30% 70%, rgba(102,126,234,0.08) 0%, transparent 60%),
                radial-gradient(circle at 70% 30%, rgba(118,75,162,0.08) 0%, transparent 60%);
    animation: heroGlow 15s ease-in-out infinite;
}
@keyframes heroGlow {
    0%, 100% { transform: translate(0, 0); }
    50% { transform: translate(5%, 5%); }
}
.hero-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: center;
    position: relative;
    z-index: 1;
}
.hero h1 {
    font-size: 3.2rem;
    font-weight: 800;
    line-height: 1.2;
    margin-bottom: 20px;
}
.hero p {
    font-size: 1.2rem;
    color: #555;
    margin-bottom: 30px;
}
.dark-mode .hero p {
    color: #bbb;
}
.hero-banner {
    border-radius: 24px;
    overflow: hidden;
    box-shadow: 0 20px 60px rgba(0,0,0,0.15);
    transition: box-shadow 0.3s;
}
.hero-banner:hover {
    box-shadow: 0 25px 70px rgba(0,0,0,0.2);
}

/* Banner Slider */
.banner-slider {
    position: relative;
    width: 100%;
    aspect-ratio: 16/9;
    overflow: hidden;
    border-radius: 24px;
}
.banner-slide {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    opacity: 0;
    transition: opacity 0.8s ease;
}
.banner-slide.active {
    opacity: 1;
}
.banner-slide svg {
    width: 100%;
    height: 100%;
    object-fit: cover;
}
.banner-dots {
    position: absolute;
    bottom: 20px;
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    gap: 10px;
}
.banner-dot {
    width: 12px;
    height: 12px;
    border-radius: 50%;
    background: rgba(255,255,255,0.5);
    cursor: pointer;
    transition: background 0.3s, transform 0.3s;
}
.banner-dot:hover {
    transform: scale(1.3);
}
.banner-dot.active {
    background: #fff;
}

/* ========== Statistics ========== */
.statistics {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: #fff;
    padding: 60px 0;
    position: relative;
    overflow: hidden;
}
.statistics::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: repeating-linear-gradient(45deg, transparent, transparent 40px, rgba(255,255,255,0.03) 40px, rgba(255,255,255,0.03) 80px);
}
.stat-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 30px;
    text-align: center;
    position: relative;
    z-index: 1;
}
.stat-item h3 {
    font-size: 2.8rem;
    font-weight: 700;
    transition: transform 0.3s;
}
.stat-item:hover h3 {
    transform: scale(1.05);
}
.stat-item p {
    opacity: 0.8;
    font-size: 1rem;
}

/* ========== Products ========== */
.products .product-grid,
.product-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 30px;
}
.product-card {
    padding: 30px;
    text-align: center;
}
.product-card svg {
    width: 80px;
    height: 80px;
    margin: 0 auto 20px;
    transition: transform 0.3s;
}
.product-card:hover svg {
    transform: scale(1.1) rotate(5deg);
}

/* ========== FAQ ========== */
.faq-item {
    border-bottom: 1px solid #e0e0e0;
    padding: 16px 0;
    transition: border-color 0.3s;
}
.dark-mode .faq-item {
    border-color: #333;
}
.faq-question {
    display: flex;
    justify-content: space-between;
    align-items: center;
    cursor: pointer;
    font-weight: 600;
    font-size: 1.1rem;
    padding: 8px 0;
    transition: color 0.3s;
}
.faq-question:hover {
    color: #667eea;
}
.faq-question::after {
    content: '+';
    font-size: 1.5rem;
    transition: transform 0.3s;
}
.faq-item.open .faq-question::after {
    content: '−';
    transform: rotate(180deg);
}
.faq-answer {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.4s ease, padding 0.3s ease;
    padding: 0 16px;
    color: #666;
}
.dark-mode .faq-answer {
    color: #aaa;
}
.faq-item.open .faq-answer {
    max-height: 300px;
    padding: 16px 16px 0;
}

/* ========== Footer ========== */
footer {
    background: #1a1a2e;
    color: #ccc;
    padding: 60px 0 20px;
}
.footer-grid {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1fr;
    gap: 40px;
    margin-bottom: 40px;
}
footer h4 {
    color: #fff;
    margin-bottom: 20px;
    position: relative;
    display: inline-block;
}
footer h4::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 40px;
    height: 2px;
    background: linear-gradient(135deg, #667eea, #764ba2);
}
footer a {
    color: #aaa;
    display: block;
    margin-bottom: 8px;
    transition: color 0.3s, padding-left 0.3s;
}
footer a:hover {
    color: #667eea;
    padding-left: 5px;
}
.footer-bottom {
    border-top: 1px solid #333;
    padding-top: 20px;
    display: flex;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: 16px;
    font-size: 0.9rem;
}
.footer-bottom a {
    display: inline;
    margin: 0 4px;
}

/* ========== Back to Top ========== */
.back-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 50px;
    height: 50px;
    border-radius: 50%;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: #fff;
    border: none;
    cursor: pointer;
    font-size: 1.5rem;
    display: none;
    align-items: center;
    justify-content: center;
    box-shadow: 0 4px 20px rgba(102,126,234,0.4);
    z-index: 999;
    transition: transform 0.3s, box-shadow 0.3s;
}
.back-to-top:hover {
    transform: scale(1.1);
    box-shadow: 0 6px 30px rgba(102,126,234,0.6);
}
.back-to-top.show {
    display: flex;
}

/* ========== Search & Contact ========== */
.search-box {
    display: flex;
    max-width: 500px;
    margin: 20px auto;
}
.search-box input {
    flex: 1;
    padding: 14px 20px;
    border: 2px solid #e0e0e0;
    border-radius: 50px 0 0 50px;
    outline: none;
    font-size: 1rem;
    background: #fff;
    transition: border-color 0.3s;
}
.search-box input:focus {
    border-color: #667eea;
}
.dark-mode .search-box input {
    background: #1a1a2e;
    border-color: #333;
    color: #e0e0e0;
}
.dark-mode .search-box input:focus {
    border-color: #764ba2;
}
.search-box button {
    padding: 14px 24px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: #fff;
    border: none;
    border-radius: 0 50px 50px 0;
    cursor: pointer;
    font-weight: 600;
    transition: opacity 0.3s;
}
.search-box button:hover {
    opacity: 0.9;
}
.search-results {
    display: none;
    margin-top: 20px;
    padding: 20px;
}
.search-results.show {
    display: block;
}

/* ========== Breadcrumb ========== */
.breadcrumb {
    display: flex;
    gap: 8px;
    flex-wrap: wrap;
    padding: 12px 0;
    font-size: 0.9rem;
    color: #888;
}
.breadcrumb a {
    color: #667eea;
    transition: color 0.3s;
}
.breadcrumb a:hover {
    color: #764ba2;
}
.breadcrumb span {
    color: #aaa;
}

/* ========== Lazy Load Placeholder ========== */
.lazy-placeholder {
    background: #e0e0e0;
    border-radius: 12px;
    min-height: 200px;
    animation: shimmer 1.5s infinite;
}
@keyframes shimmer {
    0% { opacity: 0.5; }
    50% { opacity: 1; }
    100% { opacity: 0.5; }
}
.dark-mode .lazy-placeholder {
    background: #2a2a3e;
}

/* ========== Additional Section Styles ========== */
#advantages {
    background: #f0f2f5;
}
.dark-mode #advantages {
    background: #0a0a15;
}
#cases {
    background: #f0f2f5;
}
.dark-mode #cases {
    background: #0a0a15;
}
#testimonials {
    background: #f0f2f5;
}
#contact {
    background: #f0f2f5;
}
.dark-mode #contact {
    background: #0a0a15;
}
.faq-list {
    background: transparent;
}

/* 合作伙伴卡片 */
.partner-card {
    min-height: 100px;
    display: flex;
    align-items: center;
    justify-content: center;
}

/* 统计数字动画 */
.stat-number {
    display: inline-block;
}

/* Previous / Next 导航 */
.prev-next {
    display: flex;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: 16px;
}
.prev-next a {
    color: #667eea;
    transition: color 0.3s, transform 0.3s;
}
.prev-next a:hover {
    color: #764ba2;
    transform: translateX(3px);
}

/* ========== 响应式 ========== */
@media (max-width: 1024px) and (min-width: 769px) {
    .grid-4 {
        grid-template-columns: 1fr 1fr;
    }
}

@media (max-width: 768px) {
    .grid-2, .grid-3, .grid-4 {
        grid-template-columns: 1fr;
    }
    .hero-content {
        grid-template-columns: 1fr;
        text-align: center;
    }
    .hero h1 {
        font-size: 2.2rem;
    }
    .hero p {
        font-size: 1rem;
    }
    .stat-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    .stat-item h3 {
        font-size: 2rem;
    }
    .section-title {
        font-size: 1.8rem;
    }
    .footer-grid {
        grid-template-columns: 1fr;
    }
    nav ul {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background: rgba(255,255,255,0.98);
        backdrop-filter: blur(20px);
        flex-direction: column;
        padding: 20px;
        gap: 16px;
        box-shadow: 0 20px 40px rgba(0,0,0,0.1);
    }
    .dark-mode nav ul {
        background: rgba(15,15,26,0.98);
    }
    nav ul.open {
        display: flex;
    }
    .mobile-menu-btn {
        display: block;
    }
    .header-inner {
        padding: 10px 16px;
    }
    .hero {
        padding: 120px 0 60px;
    }
    .py-40 {
        padding: 50px 0;
    }
    .py-20 {
        padding: 30px 0;
    }
    .banner-dot {
        width: 10px;
        height: 10px;
    }
    .back-to-top {
        width: 44px;
        height: 44px;
        font-size: 1.2rem;
        bottom: 20px;
        right: 20px;
    }
}

@media (max-width: 480px) {
    .hero h1 {
        font-size: 1.8rem;
    }
    .stat-grid {
        grid-template-columns: 1fr 1fr;
        gap: 20px;
    }
    .stat-item h3 {
        font-size: 1.6rem;
    }
    .container {
        padding: 0 12px;
    }
    .btn-primary {
        padding: 12px 28px;
        font-size: 0.95rem;
    }
}