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

html {
    scroll-behavior: smooth;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Noto Sans SC', sans-serif;
    line-height: 1.7;
    color: #1e293b;
    background: #f8fafc;
    transition: background 0.4s ease, color 0.4s ease;
    -webkit-font-smoothing: antialiased;
}

body.dark-mode {
    background: #0f172a;
    color: #e2e8f0;
}

/* ===== 容器 ===== */
.container {
    max-width: 1240px;
    margin: 0 auto;
    padding: 0 24px;
}

/* ===== 标题 & 文本 ===== */
h1, h2, h3, h4 {
    font-weight: 700;
    line-height: 1.25;
    letter-spacing: -0.02em;
}

h1 {
    font-size: clamp(1.6rem, 4vw, 2.6rem);
    color: #0f172a;
}
body.dark-mode h1 { color: #fbbf24; }

h2 {
    font-size: clamp(1.3rem, 3vw, 2rem);
    color: #0f172a;
    margin-bottom: 28px;
    position: relative;
    display: inline-block;
}
h2::after {
    content: '';
    position: absolute;
    bottom: -8px;
    left: 0;
    width: 60px;
    height: 4px;
    background: linear-gradient(90deg, #f59e0b, #ef4444);
    border-radius: 4px;
}
body.dark-mode h2 { color: #fbbf24; }
body.dark-mode h2::after { background: linear-gradient(90deg, #fbbf24, #f472b6); }

h3 {
    font-size: 1.2rem;
    color: #1e293b;
    margin-bottom: 8px;
}
body.dark-mode h3 { color: #f1f5f9; }

p {
    margin-bottom: 16px;
    color: #475569;
}
body.dark-mode p { color: #94a3b8; }

a {
    color: #3b82f6;
    text-decoration: none;
    transition: color 0.2s;
}
a:hover { color: #2563eb; text-decoration: underline; }

img {
    max-width: 100%;
    height: auto;
    display: block;
    border-radius: 12px;
}

/* ===== 头部 & 导航 ===== */
header {
    position: sticky;
    top: 0;
    z-index: 1000;
    background: rgba(255, 255, 255, 0.85);
    backdrop-filter: blur(16px) saturate(180%);
    -webkit-backdrop-filter: blur(16px) saturate(180%);
    box-shadow: 0 1px 3px rgba(0,0,0,0.06), 0 1px 2px rgba(0,0,0,0.04);
    transition: background 0.4s, box-shadow 0.3s;
}
body.dark-mode header {
    background: rgba(15, 23, 42, 0.85);
    backdrop-filter: blur(16px) saturate(180%);
    box-shadow: 0 1px 3px rgba(0,0,0,0.3);
}

.nav-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 12px 24px;
    max-width: 1240px;
    margin: 0 auto;
}

.logo img {
    height: 44px;
    transition: transform 0.3s;
}
.logo:hover img { transform: scale(1.04); }

.nav-menu {
    display: flex;
    list-style: none;
    gap: 6px;
}

.nav-menu li a {
    color: #334155;
    font-weight: 500;
    padding: 10px 16px;
    border-radius: 40px;
    transition: background 0.3s, color 0.3s, transform 0.2s;
    font-size: 0.95rem;
    position: relative;
}
body.dark-mode .nav-menu li a { color: #cbd5e1; }

.nav-menu li a:hover,
.nav-menu li a.active {
    background: linear-gradient(135deg, #e0f2fe, #dbeafe);
    color: #1e40af;
    transform: translateY(-1px);
}
body.dark-mode .nav-menu li a:hover,
body.dark-mode .nav-menu li a.active {
    background: linear-gradient(135deg, #1e293b, #334155);
    color: #fbbf24;
}

.nav-actions {
    display: flex;
    gap: 8px;
    align-items: center;
}

.nav-actions button {
    background: transparent;
    border: none;
    cursor: pointer;
    padding: 8px 10px;
    border-radius: 50%;
    transition: background 0.3s, transform 0.2s;
    color: #475569;
    display: flex;
    align-items: center;
}
body.dark-mode .nav-actions button { color: #cbd5e1; }

.nav-actions button:hover {
    background: rgba(59, 130, 246, 0.1);
    transform: scale(1.1);
}
body.dark-mode .nav-actions button:hover { background: rgba(251, 191, 36, 0.15); }

.mobile-menu-toggle { display: none; }

/* 搜索栏 */
.search-bar {
    display: none;
    padding: 12px 24px;
    background: rgba(241, 245, 249, 0.9);
    backdrop-filter: blur(8px);
    border-top: 1px solid #e2e8f0;
}
body.dark-mode .search-bar {
    background: rgba(30, 41, 59, 0.9);
    border-top-color: #334155;
}

.search-bar input {
    width: 100%;
    max-width: 600px;
    margin: 0 auto;
    display: block;
    padding: 12px 20px;
    border: 1px solid #cbd5e1;
    border-radius: 40px;
    font-size: 0.95rem;
    background: #fff;
    transition: border-color 0.3s, box-shadow 0.3s;
}
body.dark-mode .search-bar input {
    background: #1e293b;
    border-color: #475569;
    color: #f1f5f9;
}
.search-bar input:focus {
    outline: none;
    border-color: #3b82f6;
    box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.2);
}

.search-bar button {
    display: none;
}

/* 面包屑 */
.breadcrumb {
    background: rgba(255, 255, 255, 0.7);
    backdrop-filter: blur(8px);
    padding: 10px 24px;
    border-bottom: 1px solid #e2e8f0;
}
body.dark-mode .breadcrumb {
    background: rgba(15, 23, 42, 0.7);
    border-bottom-color: #334155;
}

.breadcrumb ol {
    list-style: none;
    display: flex;
    flex-wrap: wrap;
    gap: 6px;
    max-width: 1240px;
    margin: 0 auto;
}

.breadcrumb li {
    font-size: 0.85rem;
    color: #64748b;
}
.breadcrumb li::after {
    content: "›";
    margin-left: 8px;
    color: #94a3b8;
}
.breadcrumb li:last-child::after { content: ""; }

.breadcrumb a {
    color: #3b82f6;
    font-size: 0.85rem;
}
body.dark-mode .breadcrumb a { color: #60a5fa; }

/* ===== 响应式导航 ===== */
@media (max-width: 900px) {
    .nav-menu {
        display: none;
        flex-direction: column;
        position: absolute;
        top: 68px;
        left: 0;
        width: 100%;
        background: rgba(255, 255, 255, 0.98);
        backdrop-filter: blur(20px);
        box-shadow: 0 12px 24px rgba(0,0,0,0.1);
        padding: 12px 0;
        border-bottom: 1px solid #e2e8f0;
    }
    body.dark-mode .nav-menu {
        background: rgba(15, 23, 42, 0.98);
        border-bottom-color: #334155;
    }
    .nav-menu.open { display: flex; }

    .nav-menu li a {
        padding: 14px 24px;
        border-radius: 0;
        font-size: 1rem;
    }

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

/* ===== Hero Banner ===== */
.hero-banner {
    position: relative;
    overflow: hidden;
    height: clamp(380px, 50vw, 620px);
    background: linear-gradient(135deg, #0f172a, #1e293b);
}

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

.slide {
    position: absolute;
    top: 0; left: 0;
    width: 100%; height: 100%;
    opacity: 0;
    transition: opacity 0.9s ease;
}
.slide.active { opacity: 1; }

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

.banner-nav {
    position: absolute;
    bottom: 24px;
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    gap: 12px;
    z-index: 10;
}

.banner-dot {
    width: 14px;
    height: 14px;
    border-radius: 50%;
    background: rgba(255,255,255,0.35);
    border: 2px solid rgba(255,255,255,0.5);
    cursor: pointer;
    transition: all 0.3s;
}
.banner-dot.active {
    background: #fbbf24;
    border-color: #fbbf24;
    transform: scale(1.2);
}
.banner-dot:hover { background: rgba(255,255,255,0.6); }

.banner-content {
    position: absolute;
    bottom: 80px;
    left: 50%;
    transform: translateX(-50%);
    text-align: center;
    color: #fff;
    background: rgba(0, 0, 0, 0.45);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    padding: 28px 40px;
    border-radius: 24px;
    max-width: 800px;
    width: 90%;
    border: 1px solid rgba(255,255,255,0.15);
    box-shadow: 0 20px 40px rgba(0,0,0,0.3);
}

.banner-content h1 {
    font-size: clamp(1.2rem, 3vw, 2rem);
    margin-bottom: 12px;
    color: #fff;
    text-shadow: 0 2px 8px rgba(0,0,0,0.3);
}

.banner-content p {
    font-size: clamp(0.85rem, 1.5vw, 1.05rem);
    color: rgba(255,255,255,0.9);
    line-height: 1.6;
}

@media (max-width: 640px) {
    .hero-banner { height: 340px; }
    .banner-content { bottom: 40px; padding: 20px 24px; }
}

/* ===== 通用 Section ===== */
section {
    padding: 70px 0;
}

/* ===== 品牌介绍 ===== */
.brand-intro {
    background: linear-gradient(180deg, #f8fafc, #ffffff);
}
body.dark-mode .brand-intro {
    background: linear-gradient(180deg, #0f172a, #1e293b);
}

.brand-intro .brand-content {
    display: flex;
    gap: 40px;
    align-items: center;
}

.brand-intro .brand-img {
    width: 420px;
    border-radius: 20px;
    box-shadow: 0 12px 28px rgba(0,0,0,0.08);
    transition: transform 0.4s, box-shadow 0.4s;
    flex-shrink: 0;
}
.brand-intro .brand-img:hover {
    transform: scale(1.02);
    box-shadow: 0 20px 40px rgba(0,0,0,0.12);
}

.brand-text p {
    font-size: 1rem;
    line-height: 1.8;
}

@media (max-width: 768px) {
    .brand-intro .brand-content { flex-direction: column; }
    .brand-intro .brand-img { width: 100%; max-width: 400px; }
}

/* ===== 企业文化 ===== */
.culture {
    background: #ffffff;
}
body.dark-mode .culture { background: #1e293b; }

.culture-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    gap: 30px;
}

.culture-card {
    background: #f8fafc;
    border-radius: 20px;
    padding: 32px 24px;
    text-align: center;
    box-shadow: 0 4px 12px rgba(0,0,0,0.04);
    transition: all 0.4s cubic-bezier(0.25, 0.46, 0.45, 0.94);
    border: 1px solid #e2e8f0;
}
body.dark-mode .culture-card {
    background: #1e293b;
    border-color: #334155;
}

.culture-card:hover {
    transform: translateY(-8px);
    box-shadow: 0 16px 32px rgba(0,0,0,0.1);
    border-color: #fbbf24;
}

.culture-card img {
    margin: 0 auto 18px;
    width: 80px;
    height: 80px;
    border-radius: 50%;
    object-fit: cover;
}

.culture-card h3 {
    margin-bottom: 12px;
    font-size: 1.2rem;
}

.culture-card p {
    font-size: 0.95rem;
    line-height: 1.6;
}

/* ===== 团队介绍 ===== */
.team {
    background: linear-gradient(135deg, #f1f5f9, #e2e8f0);
}
body.dark-mode .team {
    background: linear-gradient(135deg, #0f172a, #1e293b);
}

.team-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    gap: 30px;
}

.team-card {
    background: #fff;
    border-radius: 20px;
    padding: 28px 20px;
    text-align: center;
    box-shadow: 0 4px 12px rgba(0,0,0,0.06);
    transition: all 0.4s;
    border: 1px solid #e2e8f0;
}
body.dark-mode .team-card {
    background: #1e293b;
    border-color: #334155;
}

.team-card:hover {
    transform: translateY(-6px) scale(1.01);
    box-shadow: 0 16px 32px rgba(0,0,0,0.1);
}

.team-card img {
    margin: 0 auto 16px;
    width: 120px;
    height: 120px;
    border-radius: 50%;
    object-fit: cover;
    border: 3px solid #e2e8f0;
    transition: border-color 0.3s;
}
.team-card:hover img { border-color: #fbbf24; }

.team-card h3 {
    font-size: 1.15rem;
    margin-bottom: 4px;
}

.team-card p {
    font-size: 0.9rem;
    color: #64748b;
}
body.dark-mode .team-card p { color: #94a3b8; }

/* ===== 产品中心 ===== */
.products {
    background: #ffffff;
}
body.dark-mode .products { background: #0f172a; }

.product-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    gap: 28px;
}

.product-card {
    background: #f8fafc;
    border-radius: 20px;
    padding: 24px;
    text-align: center;
    box-shadow: 0 4px 12px rgba(0,0,0,0.04);
    transition: all 0.4s cubic-bezier(0.25, 0.46, 0.45, 0.94);
    border: 1px solid #e2e8f0;
    overflow: hidden;
}
body.dark-mode .product-card {
    background: #1e293b;
    border-color: #334155;
}

.product-card:hover {
    transform: translateY(-6px);
    box-shadow: 0 20px 40px rgba(0,0,0,0.1);
    border-color: #60a5fa;
}

.product-card img {
    margin: 0 auto 16px;
    border-radius: 16px;
    transition: transform 0.5s;
}
.product-card:hover img { transform: scale(1.04); }

.product-card h3 {
    font-size: 1.2rem;
    margin-bottom: 10px;
}

.product-card p {
    font-size: 0.95rem;
    line-height: 1.6;
}

/* ===== 产品优势 ===== */
.advantages {
    background: linear-gradient(135deg, #f0f9ff, #e0f2fe);
}
body.dark-mode .advantages {
    background: linear-gradient(135deg, #0f172a, #1e293b);
}

.advantage-list {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.advantage-item {
    display: flex;
    gap: 24px;
    align-items: center;
    background: #fff;
    border-radius: 20px;
    padding: 24px 28px;
    box-shadow: 0 4px 12px rgba(0,0,0,0.04);
    transition: all 0.4s;
    border: 1px solid #e2e8f0;
}
body.dark-mode .advantage-item {
    background: #1e293b;
    border-color: #334155;
}

.advantage-item:hover {
    transform: translateX(6px);
    box-shadow: 0 12px 24px rgba(0,0,0,0.08);
    border-color: #fbbf24;
}

.advantage-item img {
    flex-shrink: 0;
    width: 60px;
    height: 60px;
    border-radius: 16px;
}

.advantage-item h3 {
    font-size: 1.15rem;
    margin-bottom: 4px;
}

.advantage-item p {
    font-size: 0.95rem;
    margin-bottom: 0;
}

/* ===== 服务支持 ===== */
.services {
    background: #ffffff;
}
body.dark-mode .services { background: #0f172a; }

.service-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    gap: 28px;
}

.service-card {
    background: #f8fafc;
    border-radius: 20px;
    padding: 28px 24px;
    text-align: center;
    box-shadow: 0 4px 12px rgba(0,0,0,0.04);
    transition: all 0.4s;
    border: 1px solid #e2e8f0;
}
body.dark-mode .service-card {
    background: #1e293b;
    border-color: #334155;
}

.service-card:hover {
    transform: translateY(-6px);
    box-shadow: 0 16px 32px rgba(0,0,0,0.08);
}

.service-card img {
    margin: 0 auto 18px;
    width: 80px;
    height: 80px;
    border-radius: 50%;
}

.service-card h3 {
    margin-bottom: 10px;
}

.service-card p {
    font-size: 0.95rem;
    line-height: 1.6;
}

/* ===== 核心优势 ===== */
.core-advantages {
    background: linear-gradient(180deg, #f8fafc, #ffffff);
}
body.dark-mode .core-advantages {
    background: linear-gradient(180deg, #0f172a, #1e293b);
}

.core-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 24px;
}

.core-item {
    background: #fff;
    border-radius: 20px;
    padding: 28px 20px;
    text-align: center;
    box-shadow: 0 4px 12px rgba(0,0,0,0.04);
    transition: all 0.4s;
    border: 1px solid #e2e8f0;
}
body.dark-mode .core-item {
    background: #1e293b;
    border-color: #334155;
}

.core-item:hover {
    transform: translateY(-6px) scale(1.02);
    box-shadow: 0 20px 40px rgba(0,0,0,0.1);
    border-color: #fbbf24;
}

.core-item img {
    margin: 0 auto 16px;
    width: 70px;
    height: 70px;
    border-radius: 18px;
}

.core-item h3 {
    font-size: 1.1rem;
    margin-bottom: 8px;
}

.core-item p {
    font-size: 0.9rem;
    line-height: 1.6;
}

/* ===== 解决方案 ===== */
.solutions {
    background: #ffffff;
}
body.dark-mode .solutions { background: #1e293b; }

.solution-list {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.solution-item {
    background: #f8fafc;
    border-radius: 20px;
    padding: 24px 28px;
    box-shadow: 0 4px 12px rgba(0,0,0,0.04);
    transition: all 0.4s;
    border-left: 5px solid #3b82f6;
}
body.dark-mode .solution-item {
    background: #1e293b;
    border-left-color: #fbbf24;
}

.solution-item:hover {
    transform: translateX(6px);
    box-shadow: 0 12px 24px rgba(0,0,0,0.08);
}

.solution-item h3 {
    font-size: 1.15rem;
    margin-bottom: 8px;
}

.solution-item p {
    font-size: 0.95rem;
    margin-bottom: 0;
}

/* ===== 应用行业 ===== */
.industries {
    background: linear-gradient(135deg, #f1f5f9, #e2e8f0);
}
body.dark-mode .industries {
    background: linear-gradient(135deg, #0f172a, #1e293b);
}

.industry-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 28px;
}

.industry-card {
    background: #fff;
    border-radius: 20px;
    padding: 24px;
    text-align: center;
    box-shadow: 0 4px 12px rgba(0,0,0,0.04);
    transition: all 0.4s;
    border: 1px solid #e2e8f0;
}
body.dark-mode .industry-card {
    background: #1e293b;
    border-color: #334155;
}

.industry-card:hover {
    transform: translateY(-6px);
    box-shadow: 0 16px 32px rgba(0,0,0,0.1);
}

.industry-card img {
    margin: 0 auto 16px;
    border-radius: 16px;
}

.industry-card h3 {
    margin-bottom: 8px;
}

.industry-card p {
    font-size: 0.9rem;
    line-height: 1.6;
}

/* ===== 成功案例 ===== */
.cases {
    background: #ffffff;
}
body.dark-mode .cases { background: #0f172a; }

.case-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 28px;
}

.case-card {
    background: #f8fafc;
    border-radius: 20px;
    padding: 24px;
    text-align: center;
    box-shadow: 0 4px 12px rgba(0,0,0,0.04);
    transition: all 0.4s;
    border: 1px solid #e2e8f0;
}
body.dark-mode .case-card {
    background: #1e293b;
    border-color: #334155;
}

.case-card:hover {
    transform: translateY(-6px);
    box-shadow: 0 20px 40px rgba(0,0,0,0.1);
}

.case-card img {
    margin: 0 auto 16px;
    border-radius: 16px;
}

.case-card h3 {
    font-size: 1.1rem;
    margin-bottom: 8px;
}

.case-card p {
    font-size: 0.95rem;
    line-height: 1.6;
}

/* ===== 客户评价 ===== */
.testimonials {
    background: linear-gradient(180deg, #f8fafc, #ffffff);
}
body.dark-mode .testimonials {
    background: linear-gradient(180deg, #0f172a, #1e293b);
}

.testimonial-slider {
    display: flex;
    gap: 24px;
    overflow-x: auto;
    padding: 16px 0 24px;
    scroll-snap-type: x mandatory;
    -webkit-overflow-scrolling: touch;
}

.testimonial-card {
    min-width: 300px;
    flex-shrink: 0;
    background: #fff;
    border-radius: 20px;
    padding: 28px 24px;
    box-shadow: 0 4px 12px rgba(0,0,0,0.04);
    scroll-snap-align: start;
    transition: all 0.4s;
    border: 1px solid #e2e8f0;
}
body.dark-mode .testimonial-card {
    background: #1e293b;
    border-color: #334155;
}

.testimonial-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 16px 32px rgba(0,0,0,0.08);
}

.testimonial-card p:first-child {
    font-style: italic;
    font-size: 1rem;
    line-height: 1.7;
    color: #334155;
}
body.dark-mode .testimonial-card p:first-child { color: #e2e8f0; }

.testimonial-card p:last-child {
    font-weight: 600;
    color: #3b82f6;
    margin-top: 12px;
    margin-bottom: 0;
}

/* ===== 新闻资讯 ===== */
.news {
    background: #ffffff;
}
body.dark-mode .news { background: #0f172a; }

.news-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 28px;
}

.news-card {
    background: #f8fafc;
    border-radius: 20px;
    padding: 24px;
    box-shadow: 0 4px 12px rgba(0,0,0,0.04);
    transition: all 0.4s;
    border: 1px solid #e2e8f0;
    text-align: left;
}
body.dark-mode .news-card {
    background: #1e293b;
    border-color: #334155;
}

.news-card:hover {
    transform: translateY(-6px);
    box-shadow: 0 20px 40px rgba(0,0,0,0.1);
}

.news-card img {
    margin-bottom: 16px;
    border-radius: 16px;
}

.news-card h3 {
    font-size: 1.1rem;
    margin-bottom: 6px;
}

.news-card p {
    font-size: 0.9rem;
    line-height: 1.6;
    color: #64748b;
}
body.dark-mode .news-card p { color: #94a3b8; }

.read-more {
    display: inline-block;
    padding: 8px 20px;
    background: linear-gradient(135deg, #3b82f6, #2563eb);
    color: #fff;
    border-radius: 40px;
    font-size: 0.9rem;
    font-weight: 500;
    transition: all 0.3s;
    margin-top: 8px;
    border: none;
    cursor: pointer;
}
.read-more:hover {
    background: linear-gradient(135deg, #2563eb, #1d4ed8);
    transform: translateY(-2px);
    box-shadow: 0 6px 16px rgba(59, 130, 246, 0.3);
    text-decoration: none;
    color: #fff;
}

/* ===== 最新文章 ===== */
.articles {
    background: linear-gradient(135deg, #f1f5f9, #e2e8f0);
}
body.dark-mode .articles {
    background: linear-gradient(135deg, #0f172a, #1e293b);
}

.article-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 28px;
}

.article-card {
    background: #fff;
    border-radius: 20px;
    padding: 24px;
    box-shadow: 0 4px 12px rgba(0,0,0,0.04);
    transition: all 0.4s;
    border: 1px solid #e2e8f0;
}
body.dark-mode .article-card {
    background: #1e293b;
    border-color: #334155;
}

.article-card:hover {
    transform: translateY(-6px);
    box-shadow: 0 20px 40px rgba(0,0,0,0.1);
}

.article-card h3 {
    font-size: 1.1rem;
    margin-bottom: 6px;
}

.article-card p {
    font-size: 0.9rem;
    line-height: 1.6;
    color: #64748b;
}
body.dark-mode .article-card p { color: #94a3b8; }

/* ===== FAQ ===== */
.faq {
    background: #ffffff;
}
body.dark-mode .faq { background: #0f172a; }

.faq-list {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.faq-item {
    background: #f8fafc;
    border-radius: 16px;
    padding: 18px 24px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.04);
    cursor: pointer;
    transition: all 0.3s;
    border: 1px solid #e2e8f0;
}
body.dark-mode .faq-item {
    background: #1e293b;
    border-color: #334155;
}

.faq-item:hover {
    border-color: #3b82f6;
    box-shadow: 0 4px 16px rgba(0,0,0,0.06);
}

.faq-item h3 {
    font-size: 1.05rem;
    margin-bottom: 4px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}
.faq-item h3::after {
    content: '+';
    font-size: 1.4rem;
    color: #3b82f6;
    transition: transform 0.3s;
}
.faq-item.active h3::after {
    content: '−';
    transform: rotate(180deg);
}

.faq-item p {
    display: none;
    margin-top: 12px;
    font-size: 0.95rem;
    line-height: 1.7;
    color: #475569;
}
body.dark-mode .faq-item p { color: #94a3b8; }

.faq-item.active p { display: block; }

/* ===== HowTo ===== */
.howto {
    background: linear-gradient(180deg, #f8fafc, #ffffff);
}
body.dark-mode .howto {
    background: linear-gradient(180deg, #0f172a, #1e293b);
}

.howto-content {
    background: #fff;
    border-radius: 24px;
    padding: 36px 32px;
    box-shadow: 0 4px 16px rgba(0,0,0,0.04);
    border: 1px solid #e2e8f0;
}
body.dark-mode .howto-content {
    background: #1e293b;
    border-color: #334155;
}

.howto-content h3 {
    font-size: 1.2rem;
    margin-top: 24px;
    margin-bottom: 12px;
    color: #0f172a;
}
body.dark-mode .howto-content h3 { color: #f1f5f9; }

.howto-content h3:first-child { margin-top: 0; }

.howto-content ol {
    padding-left: 24px;
    margin-bottom: 20px;
}

.howto-content ol li {
    margin-bottom: 10px;
    line-height: 1.7;
    font-size: 0.95rem;
}

.howto-content p {
    font-size: 0.95rem;
    line-height: 1.7;
}

/* ===== 联系我们 ===== */
.contact {
    background: #ffffff;
}
body.dark-mode .contact { background: #0f172a; }

.contact-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 30px;
}

.contact-info,
.contact-qr {
    background: #f8fafc;
    border-radius: 20px;
    padding: 28px 24px;
    box-shadow: 0 4px 12px rgba(0,0,0,0.04);
    border: 1px solid #e2e8f0;
    transition: all 0.4s;
}
body.dark-mode .contact-info,
body.dark-mode .contact-qr {
    background: #1e293b;
    border-color: #334155;
}

.contact-info:hover,
.contact-qr:hover {
    transform: translateY(-4px);
    box-shadow: 0 16px 32px rgba(0,0,0,0.08);
}

.contact-info h3,
.contact-qr h3 {
    font-size: 1.2rem;
    margin-bottom: 16px;
}

.contact-info p {
    font-size: 0.95rem;
    line-height: 1.8;
}

.contact-qr img {
    margin: 12px auto;
    width: 140px;
    border-radius: 12px;
    transition: transform 0.3s;
}
.contact-qr img:hover { transform: scale(1.05); }

.contact-qr p {
    text-align: center;
    font-size: 0.9rem;
    color: #64748b;
}
body.dark-mode .contact-qr p { color: #94a3b8; }

@media (max-width: 768px) {
    .contact-grid { grid-template-columns: 1fr; }
}

/* ===== 页脚 ===== */
footer {
    background: #0f172a;
    color: #cbd5e1;
    padding: 48px 24px 32px;
    border-top: 1px solid #1e293b;
}

.footer-container {
    max-width: 1240px;
    margin: 0 auto;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 36px;
}

footer h3 {
    color: #fbbf24;
    margin-bottom: 18px;
    font-size: 1.1rem;
}

footer ul {
    list-style: none;
}

footer ul li {
    margin-bottom: 10px;
}

footer a {
    color: #94a3b8;
    font-size: 0.9rem;
    transition: color 0.3s;
}
footer a:hover {
    color: #fbbf24;
    text-decoration: none;
}

footer p {
    font-size: 0.85rem;
    line-height: 1.7;
    color: #94a3b8;
    margin-bottom: 10px;
}

/* ===== 返回顶部 ===== */
.back-to-top {
    position: fixed;
    bottom: 32px;
    right: 32px;
    width: 52px;
    height: 52px;
    border-radius: 50%;
    background: linear-gradient(135deg, #fbbf24, #f59e0b);
    color: #0f172a;
    border: none;
    font-size: 26px;
    cursor: pointer;
    box-shadow: 0 8px 20px rgba(251, 191, 36, 0.3);
    display: none;
    align-items: center;
    justify-content: center;
    transition: all 0.3s;
    z-index: 999;
    line-height: 1;
}
.back-to-top.show { display: flex; }

.back-to-top:hover {
    transform: translateY(-4px) scale(1.05);
    box-shadow: 0 12px 28px rgba(251, 191, 36, 0.4);
    background: linear-gradient(135deg, #f59e0b, #d97706);
}

/* ===== 滚动动画 ===== */
.fade-in {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.7s ease, transform 0.7s cubic-bezier(0.25, 0.46, 0.45, 0.94);
}

.fade-in.visible {
    opacity: 1;
    transform: translateY(0);
}

/* ===== 响应式微调 ===== */
@media (max-width: 480px) {
    .container { padding: 0 16px; }
    section { padding: 50px 0; }

    .nav-container { padding: 10px 16px; }

    .advantage-item {
        flex-direction: column;
        text-align: center;
        padding: 20px;
    }

    .howto-content { padding: 24px 18px; }

    .banner-content { padding: 16px 20px; }

    .back-to-top {
        width: 44px;
        height: 44px;
        font-size: 22px;
        bottom: 20px;
        right: 20px;
    }
}

/* ===== 暗黑模式额外适配 ===== */
body.dark-mode .breadcrumb a { color: #60a5fa; }
body.dark-mode .read-more {
    background: linear-gradient(135deg, #f59e0b, #d97706);
    color: #0f172a;
}
body.dark-mode .read-more:hover {
    background: linear-gradient(135deg, #d97706, #b45309);
    box-shadow: 0 6px 16px rgba(245, 158, 11, 0.3);
    color: #0f172a;
}

/* ===== 选择文本样式 ===== */
::selection {
    background: #fbbf24;
    color: #0f172a;
}

body.dark-mode ::selection {
    background: #f59e0b;
    color: #0f172a;
}

/* ===== 滚动条美化 ===== */
::-webkit-scrollbar {
    width: 8px;
    height: 8px;
}

::-webkit-scrollbar-track {
    background: #f1f5f9;
    border-radius: 8px;
}

::-webkit-scrollbar-thumb {
    background: #94a3b8;
    border-radius: 8px;
}

::-webkit-scrollbar-thumb:hover {
    background: #64748b;
}

body.dark-mode ::-webkit-scrollbar-track {
    background: #1e293b;
}

body.dark-mode ::-webkit-scrollbar-thumb {
    background: #475569;
}

body.dark-mode ::-webkit-scrollbar-thumb:hover {
    background: #64748b;
}