/* ============================================
   1. 全局重置 & CSS 变量
   ============================================ */
:root {
    --primary: #d3542a;
    --primary-dark: #b1431f;
    --primary-light: #f0a78a;
    --secondary: #1e2a3a;
    --bg-light: #f4f6fa;
    --bg-white: #ffffff;
    --text-dark: #1a1a2e;
    --text-muted: #5a6a7a;
    --text-light: #a0b0c0;
    --border-light: #e8edf3;
    --shadow-sm: 0 4px 20px rgba(0, 0, 0, 0.04);
    --shadow-md: 0 12px 40px rgba(0, 0, 0, 0.08);
    --shadow-lg: 0 24px 60px rgba(0, 0, 0, 0.12);
    --radius: 12px;
    --transition: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    --font: 'Inter', 'Segoe UI', 'Microsoft YaHei', sans-serif;
    --max-width: 1200px;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font);
    background: var(--bg-light);
    color: var(--text-dark);
    line-height: 1.6;
    font-size: 16px;
    -webkit-font-smoothing: antialiased;
}

a {
    text-decoration: none;
    color: inherit;
}
ul {
    list-style: none;
}
img {
    max-width: 100%;
    height: auto;
    display: block;
}

.container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 24px;
}

/* ============================================
   2. 顶部栏
   ============================================ */
.topbar {
    background: var(--secondary);
    color: rgba(255, 255, 255, 0.7);
    font-size: 13px;
    padding: 6px 0;
    border-bottom: 1px solid rgba(255, 255, 255, 0.06);
}
.topbar .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 6px 16px;
}
.topbar .seo-links a {
    color: rgba(255, 255, 255, 0.6);
    margin: 0 6px;
    font-size: 12px;
    letter-spacing: 0.3px;
}
.topbar .seo-links a:hover {
    color: #fff;
}

@media (max-width: 600px) {
    .topbar .container {
        flex-direction: column;
        text-align: center;
    }
    .topbar .seo-links {
        font-size: 12px;
    }
}

/* ============================================
   3. 头部
   ============================================ */
.header {
    background: var(--bg-white);
    padding: 16px 0;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.02);
    border-bottom: 1px solid var(--border-light);
}
.header .container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: 16px 24px;
}
.header .brand {
    display: flex;
    align-items: center;
    gap: 12px;
}
.header .brand .logo-icon {
    font-size: 32px;
    color: var(--primary);
    background: rgba(211, 84, 42, 0.10);
    width: 56px;
    height: 56px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: var(--radius);
}
.header .brand h1 {
    font-size: 26px;
    font-weight: 700;
    letter-spacing: -0.5px;
    color: var(--secondary);
}
.header .brand h1 span {
    color: var(--primary);
}
.header .brand .tagline {
    font-size: 14px;
    color: var(--text-muted);
    font-weight: 400;
    letter-spacing: 0.3px;
}
.header .contact-tel {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 22px;
    font-weight: 700;
    color: var(--primary);
    background: rgba(211, 84, 42, 0.06);
    padding: 6px 20px 6px 16px;
    border-radius: 40px;
    border: 1px solid rgba(211, 84, 42, 0.12);
}
.header .contact-tel i {
    font-size: 24px;
}

@media (max-width: 768px) {
    .header .container {
        flex-direction: column;
        align-items: center;
        text-align: center;
    }
    .header .brand {
        flex-direction: column;
        align-items: center;
    }
    .header .brand h1 {
        font-size: 22px;
    }
    .header .brand .tagline {
        font-size: 13px;
    }
    .header .contact-tel {
        font-size: 18px;
        padding: 4px 16px;
    }
}

/* ============================================
   4. 导航栏
   ============================================ */
.navbar {
    background: var(--secondary);
    position: sticky;
    top: 0;
    z-index: 999;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.08);
}
.navbar .container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    min-height: 60px;
}
.navbar .nav-toggle {
    display: none;
    background: none;
    border: none;
    color: #fff;
    font-size: 28px;
    cursor: pointer;
    padding: 6px 12px;
}

.navbar .nav-menu {
    display: flex;
    flex-wrap: nowrap;
    justify-content: space-evenly;
    width: 100%;
    align-items: center;
    gap: 0;
}
.navbar .nav-menu a {
    display: block;
    padding: 0 12px;
    height: 60px;
    line-height: 60px;
    color: rgba(255, 255, 255, 0.85);
    font-size: 16px;
    font-weight: 500;
    letter-spacing: 0.5px;
    white-space: nowrap;
    text-align: center;
    position: relative;
    transition: var(--transition);
    flex-shrink: 1;
}
.navbar .nav-menu a::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 0;
    height: 3px;
    background: var(--primary);
    transition: var(--transition);
    border-radius: 2px 2px 0 0;
}
.navbar .nav-menu a:hover,
.navbar .nav-menu a.active {
    color: #fff;
    background: rgba(255, 255, 255, 0.05);
}
.navbar .nav-menu a:hover::after,
.navbar .nav-menu a.active::after {
    width: 50%;
}

@media (max-width: 820px) {
    .navbar .nav-toggle {
        display: block;
    }
    .navbar .nav-menu {
        display: none;
        flex-direction: column;
        flex-wrap: wrap;
        position: absolute;
        top: 60px;
        left: 0;
        right: 0;
        background: var(--secondary);
        padding: 8px 0;
        border-top: 1px solid rgba(255, 255, 255, 0.06);
        box-shadow: 0 20px 40px rgba(0, 0, 0, 0.3);
        justify-content: flex-start;
        width: 100%;
    }
    .navbar .nav-menu.open {
        display: flex;
    }
    .navbar .nav-menu a {
        height: 48px;
        line-height: 48px;
        padding: 0 28px;
        text-align: center;
        white-space: normal;
        border-bottom: 1px solid rgba(255, 255, 255, 0.04);
        flex-shrink: 0;
    }
    .navbar .nav-menu a::after {
        display: none;
    }
    .navbar .nav-menu a:hover {
        background: rgba(211, 84, 42, 0.2);
    }
}

@media (min-width: 821px) and (max-width: 920px) {
    .navbar .nav-menu a {
        padding: 0 8px;
        font-size: 14px;
        letter-spacing: 0;
    }
}

/* ============================================
   5. Hero Banner
   ============================================ */
.hero {
    position: relative;
    background: var(--secondary);
    overflow: hidden;
    min-height: 420px;
    display: flex;
    align-items: center;
}
.hero .hero-slider {
    display: flex;
    transition: transform 0.7s cubic-bezier(0.25, 0.46, 0.45, 0.94);
    width: 100%;
}
.hero .hero-slide {
    min-width: 100%;
    flex-shrink: 0;
    position: relative;
}
.hero .hero-slide img {
    width: 100%;
    height: 420px;
    object-fit: cover;
    opacity: 0.7;
}
.hero .hero-overlay {
    position: absolute;
    inset: 0;
    background: linear-gradient(135deg, rgba(26, 26, 46, 0.75) 0%, rgba(30, 42, 58, 0.45) 100%);
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    padding: 40px 24px;
}
.hero .hero-overlay .hero-content {
    max-width: 720px;
    color: #fff;
}
.hero .hero-overlay h2 {
    font-size: clamp(2rem, 5vw, 3.4rem);
    font-weight: 700;
    letter-spacing: -0.5px;
    line-height: 1.2;
    margin-bottom: 16px;
}
.hero .hero-overlay h2 span {
    color: #f0a78a;
}
.hero .hero-overlay p {
    font-size: clamp(1rem, 1.6vw, 1.25rem);
    opacity: 0.9;
    max-width: 560px;
    margin: 0 auto 28px;
    line-height: 1.7;
}
.hero .hero-overlay .btn-primary {
    display: inline-block;
    background: var(--primary);
    color: #fff;
    padding: 12px 40px;
    border-radius: 40px;
    font-weight: 600;
    font-size: 16px;
    letter-spacing: 0.5px;
    transition: var(--transition);
    box-shadow: 0 8px 24px rgba(211, 84, 42, 0.3);
}
.hero .hero-overlay .btn-primary:hover {
    background: var(--primary-dark);
    transform: translateY(-2px);
    box-shadow: 0 12px 32px rgba(211, 84, 42, 0.4);
}

.hero-dots {
    position: absolute;
    bottom: 28px;
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    gap: 14px;
    z-index: 10;
}
.hero-dots .dot {
    width: 12px;
    height: 12px;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.35);
    cursor: pointer;
    transition: var(--transition);
    border: 2px solid transparent;
}
.hero-dots .dot.active {
    background: var(--primary);
    border-color: rgba(255, 255, 255, 0.6);
    transform: scale(1.2);
}

@media (max-width: 600px) {
    .hero .hero-slide img {
        height: 320px;
    }
    .hero {
        min-height: 320px;
    }
    .hero .hero-overlay .btn-primary {
        padding: 10px 28px;
        font-size: 14px;
    }
}

/* ============================================
   6. 通用标题区
   ============================================ */
.section-title {
    text-align: center;
    padding: 20px 0 8px;
}
.section-title h2 {
    font-size: clamp(1.8rem, 3.2vw, 2.6rem);
    font-weight: 700;
    color: var(--secondary);
    letter-spacing: -0.5px;
}
.section-title .sub {
    font-size: 14px;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 4px;
    margin-top: 4px;
}
.section-title .line {
    width: 60px;
    height: 4px;
    background: var(--primary);
    margin: 12px auto 0;
    border-radius: 4px;
}

/* ============================================
   7. 优势卡片
   ============================================ */
.section-advantage {
    padding: 40px 0 50px;
    background: var(--bg-white);
}
.advantage-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 24px;
    margin-top: 16px;
}
.advantage-card {
    background: var(--bg-light);
    padding: 32px 20px 28px;
    border-radius: var(--radius);
    text-align: center;
    transition: var(--transition);
    border: 1px solid transparent;
}
.advantage-card:hover {
    transform: translateY(-6px);
    border-color: var(--primary);
    box-shadow: var(--shadow-md);
    background: #fff;
}
.advantage-card .icon {
    font-size: 40px;
    color: var(--primary);
    margin-bottom: 12px;
    display: block;
}
.advantage-card h3 {
    font-size: 18px;
    font-weight: 600;
    color: var(--secondary);
    margin-bottom: 8px;
}
.advantage-card p {
    font-size: 14px;
    color: var(--text-muted);
    line-height: 1.7;
}

@media (max-width: 992px) {
    .advantage-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}
@media (max-width: 576px) {
    .advantage-grid {
        grid-template-columns: 1fr;
    }
}

/* ============================================
   8. 关于我们
   ============================================ */
.section-about {
    padding: 50px 0 60px;
    background: var(--bg-light);
}
.about-row {
    display: flex;
    align-items: center;
    gap: 48px;
    flex-wrap: wrap;
}
.about-row .about-image {
    flex: 1 1 45%;
    border-radius: var(--radius);
    overflow: hidden;
    box-shadow: var(--shadow-md);
}
.about-row .about-image img {
    width: 100%;
    height: 320px;
    object-fit: cover;
    transition: var(--transition);
}
.about-row .about-image:hover img {
    transform: scale(1.02);
}
.about-row .about-text {
    flex: 1 1 45%;
}
.about-row .about-text h3 {
    font-size: 26px;
    font-weight: 700;
    color: var(--secondary);
    margin-bottom: 16px;
    letter-spacing: -0.3px;
}
.about-row .about-text h3 span {
    color: var(--primary);
}
.about-row .about-text p {
    font-size: 15px;
    color: var(--text-muted);
    line-height: 1.8;
    margin-bottom: 12px;
}
.about-row .about-text .btn-outline {
    display: inline-block;
    border: 2px solid var(--primary);
    color: var(--primary);
    padding: 8px 32px;
    border-radius: 40px;
    font-weight: 600;
    font-size: 14px;
    transition: var(--transition);
    margin-top: 4px;
}
.about-row .about-text .btn-outline:hover {
    background: var(--primary);
    color: #fff;
}

@media (max-width: 768px) {
    .about-row {
        flex-direction: column;
        gap: 28px;
    }
    .about-row .about-image img {
        height: 240px;
    }
    .about-row .about-text h3 {
        font-size: 22px;
    }
}

/* ============================================
   9. 产品展示 ★ 已优化适配 800×600 (4:3)
   ============================================ */
.section-product {
    padding: 40px 0 50px;
    background: var(--bg-white);
}
.product-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 28px;
    margin-top: 16px;
}
.product-card {
    background: var(--bg-light);
    border-radius: var(--radius);
    overflow: hidden;
    transition: var(--transition);
    border: 1px solid var(--border-light);
}
.product-card:hover {
    transform: translateY(-6px);
    box-shadow: var(--shadow-md);
    border-color: var(--primary-light);
}
/* ★ 图片容器：固定 4:3 比例，完美适配 800×600 图片 */
.product-card .product-img {
    width: 100%;
    aspect-ratio: 4 / 3;
    overflow: hidden;
    background: #eef2f7;
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
}
.product-card .product-img img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.4s ease;
}
.product-card:hover .product-img img {
    transform: scale(1.04);
}
.product-card .info {
    padding: 16px 18px 20px;
    text-align: center;
}
.product-card .info h3 {
    font-size: 16px;
    font-weight: 600;
    color: var(--secondary);
}
.product-card .info h3 a {
    color: var(--secondary);
}
.product-card .info h3 a:hover {
    color: var(--primary);
}

@media (max-width: 992px) {
    .product-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 24px;
    }
}
@media (max-width: 576px) {
    .product-grid {
        grid-template-columns: 1fr;
        gap: 20px;
    }
}

/* ============================================
   10. 资质荣誉（首页）
   ============================================ */
.section-cert {
    padding: 40px 0 60px;
    background: #f0f4fb;
    background-image: radial-gradient(circle at 10% 20%, rgba(211, 84, 42, 0.03) 0%, transparent 60%);
}
.cert-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 28px;
    margin-top: 16px;
}

.cert-card {
    background: #fff;
    border-radius: var(--radius);
    overflow: hidden;
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--border-light);
    transition: var(--transition);
    cursor: default;
    display: flex;
    flex-direction: column;
}
.cert-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-lg);
    border-color: var(--primary);
}

.cert-card .cert-image {
    width: 100%;
    height: 220px;
    overflow: hidden;
    background: #eef2f7;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
}
.cert-card .cert-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.5s ease;
}
.cert-card:hover .cert-image img {
    transform: scale(1.06);
}

.cert-card .cert-info {
    padding: 18px 20px 22px;
    text-align: center;
    background: #fff;
    flex: 1;
    display: flex;
    flex-direction: column;
    justify-content: center;
}
.cert-card .cert-info h4 {
    font-size: 17px;
    font-weight: 700;
    color: var(--secondary);
    letter-spacing: 0.3px;
    margin-bottom: 4px;
}
.cert-card .cert-info .cert-sub {
    font-size: 13px;
    color: var(--text-muted);
    font-weight: 400;
    letter-spacing: 0.5px;
}

.cert-card .cert-badge {
    display: inline-block;
    font-size: 11px;
    font-weight: 600;
    color: var(--primary);
    background: rgba(211, 84, 42, 0.08);
    padding: 2px 14px;
    border-radius: 20px;
    letter-spacing: 0.5px;
    margin-top: 6px;
    align-self: center;
}

@media (max-width: 992px) {
    .cert-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    .cert-card .cert-image {
        height: 200px;
    }
}
@media (max-width: 576px) {
    .cert-grid {
        grid-template-columns: 1fr;
        max-width: 380px;
        margin-left: auto;
        margin-right: auto;
    }
    .cert-card .cert-image {
        height: 210px;
    }
    .cert-card .cert-info h4 {
        font-size: 16px;
    }
}

/* ============================================
   11. 案例展示（首页 & 案例页）
   ============================================ */
.section-case {
    padding: 40px 0 50px;
    background: var(--bg-white);
}
.case-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 28px;
    margin-top: 16px;
}
.case-card {
    border-radius: var(--radius);
    overflow: hidden;
    background: #fff;
    border: 1px solid var(--border-light);
    transition: var(--transition);
    box-shadow: var(--shadow-sm);
}
.case-card:hover {
    transform: translateY(-6px);
    box-shadow: var(--shadow-lg);
    border-color: var(--primary-light);
}
.case-card img {
    width: 100%;
    height: 210px;
    object-fit: cover;
}
.case-card .info {
    padding: 18px 20px 22px;
}
.case-card .info h3 {
    font-size: 17px;
    font-weight: 600;
    color: var(--secondary);
    margin-bottom: 4px;
}
.case-card .info h3 a {
    color: var(--secondary);
}
.case-card .info h3 a:hover {
    color: var(--primary);
}
.case-card .info p {
    font-size: 14px;
    color: var(--text-muted);
}

/* 案例页专用样式 */
.case-card .case-tags {
    display: flex;
    gap: 10px;
    flex-wrap: wrap;
    margin-top: 10px;
}
.case-card .case-tags .tag {
    font-size: 12px;
    color: var(--primary);
    background: rgba(211, 84, 42, 0.08);
    padding: 2px 14px;
    border-radius: 20px;
}
.case-card .case-tags .date {
    font-size: 12px;
    color: var(--text-light);
}
.case-card .case-link {
    display: inline-block;
    margin-top: 12px;
    font-size: 13px;
    font-weight: 600;
    color: var(--primary);
    transition: var(--transition);
}
.case-card .case-link:hover {
    color: var(--primary-dark);
    transform: translateX(4px);
}
.case-card .case-link i {
    margin-left: 4px;
    font-size: 12px;
}

@media (max-width: 992px) {
    .case-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}
@media (max-width: 576px) {
    .case-grid {
        grid-template-columns: 1fr;
    }
}

/* ============================================
   12. 新闻资讯
   ============================================ */
.section-news {
    padding: 40px 0 50px;
    background: var(--bg-light);
}
.news-row {
    display: flex;
    flex-wrap: wrap;
    gap: 32px;
    margin-top: 8px;
}
.news-col {
    flex: 1 1 45%;
}
.news-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 14px 0;
    border-bottom: 1px dashed var(--border-light);
    gap: 12px;
}
.news-item:last-child {
    border-bottom: none;
}
.news-item a {
    font-size: 15px;
    color: var(--text-dark);
    font-weight: 500;
    transition: var(--transition);
}
.news-item a:hover {
    color: var(--primary);
}
.news-item .date {
    font-size: 13px;
    color: var(--text-light);
    white-space: nowrap;
    flex-shrink: 0;
}

@media (max-width: 768px) {
    .news-col {
        flex: 1 1 100%;
    }
    .news-item {
        flex-wrap: wrap;
    }
    .news-item .date {
        white-space: normal;
    }
}

/* ============================================
   13. 内页通用样式
   ============================================ */
.page-banner {
    width: 100%;
    overflow: hidden;
    background: var(--secondary);
}
.page-banner img {
    width: 100%;
    height: 280px;
    object-fit: cover;
    opacity: 0.6;
}

.page-content {
    padding: 40px 0 60px;
    background: var(--bg-white);
}

.breadcrumb {
    font-size: 14px;
    color: var(--text-muted);
    padding: 0 0 20px 0;
    border-bottom: 1px solid var(--border-light);
    margin-bottom: 30px;
}
.breadcrumb a {
    color: var(--text-muted);
    transition: var(--transition);
}
.breadcrumb a:hover {
    color: var(--primary);
}
.breadcrumb .sep {
    margin: 0 8px;
    color: #ccc;
}

.page-title {
    font-size: 28px;
    font-weight: 700;
    color: var(--secondary);
    margin-bottom: 20px;
    letter-spacing: -0.5px;
}

.page-detail {
    font-size: 15px;
    color: var(--text-muted);
    line-height: 2;
}
.page-detail p {
    margin-bottom: 16px;
}
.page-detail ul {
    padding-left: 24px;
    margin-bottom: 16px;
}
.page-detail ul li {
    list-style: disc;
    margin-bottom: 8px;
}
.page-detail strong {
    color: var(--text-dark);
}

/* ============================================
   14. ★ 筛选导航（案例 & 证书共用）
   ============================================ */
.filter-tabs {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    margin-bottom: 30px;
    padding-bottom: 18px;
    border-bottom: 2px solid var(--border-light);
}
.filter-tabs a {
    display: inline-block;
    padding: 8px 26px;
    background: var(--bg-light);
    color: var(--text-muted);
    border-radius: 30px;
    font-size: 14px;
    font-weight: 500;
    transition: var(--transition);
    border: 1px solid transparent;
    cursor: pointer;
    text-decoration: none;
}
.filter-tabs a:hover {
    background: rgba(211, 84, 42, 0.08);
    color: var(--primary);
    border-color: var(--primary-light);
}
.filter-tabs a.active {
    background: var(--primary);
    color: #fff;
    border-color: var(--primary);
}
.filter-tabs a i {
    margin-right: 6px;
}

@media (max-width: 768px) {
    .filter-tabs a {
        padding: 6px 16px;
        font-size: 13px;
    }
}

/* ============================================
   15. ★ 分类标题（案例 & 证书共用）
   ============================================ */
.category-title {
    font-size: 22px;
    font-weight: 700;
    color: var(--secondary);
    padding: 20px 0 12px;
    margin: 20px 0 16px;
    border-bottom: 3px solid var(--primary);
    display: flex;
    align-items: center;
    gap: 12px;
    scroll-margin-top: 80px;
}
.category-title .cat-icon {
    font-size: 28px;
    color: var(--primary);
}
.category-title .cat-count {
    font-size: 14px;
    font-weight: 400;
    color: var(--text-light);
    margin-left: auto;
}

@media (max-width: 768px) {
    .category-title {
        font-size: 18px;
        scroll-margin-top: 70px;
    }
}

/* ============================================
   16. ★ 返回顶部（悬浮 + 文字）
   ============================================ */
#top {
    scroll-margin-top: 0;
}

.back-to-top-fixed {
    position: fixed;
    bottom: 40px;
    right: 40px;
    z-index: 999;
    display: flex;
    align-items: center;
    justify-content: center;
    width: 52px;
    height: 52px;
    background: var(--primary);
    color: #fff;
    border-radius: 50%;
    font-size: 22px;
    box-shadow: 0 6px 24px rgba(211, 84, 42, 0.35);
    transition: var(--transition);
    cursor: pointer;
    border: none;
    text-decoration: none;
    opacity: 0;
    transform: translateY(20px);
    pointer-events: none;
}
.back-to-top-fixed.show {
    opacity: 1;
    transform: translateY(0);
    pointer-events: auto;
}
.back-to-top-fixed:hover {
    background: var(--primary-dark);
    transform: translateY(-4px);
    box-shadow: 0 10px 32px rgba(211, 84, 42, 0.45);
}
.back-to-top-fixed i {
    margin: 0;
}

.back-to-top-text {
    display: inline-block;
    padding: 10px 28px;
    background: var(--secondary);
    color: #fff;
    border-radius: 40px;
    font-size: 14px;
    font-weight: 500;
    transition: var(--transition);
    margin-top: 10px;
    cursor: pointer;
    border: none;
    text-decoration: none;
}
.back-to-top-text:hover {
    background: var(--primary);
    color: #fff;
    transform: translateY(-2px);
}
.back-to-top-text i {
    margin-right: 8px;
}

@media (max-width: 768px) {
    .back-to-top-fixed {
        bottom: 20px;
        right: 20px;
        width: 44px;
        height: 44px;
        font-size: 18px;
    }
}

/* ============================================
   17. ★ 证书页专用（证书详情）
   ============================================ */
/* 证书图片上的标签 */
.cert-card .cert-image .cert-badge-tag {
    position: absolute;
    top: 14px;
    right: 14px;
    background: rgba(30, 42, 58, 0.8);
    color: #fff;
    font-size: 11px;
    font-weight: 600;
    padding: 4px 14px;
    border-radius: 20px;
    letter-spacing: 0.5px;
    backdrop-filter: blur(4px);
}

/* 证书详情列表 */
.cert-card .cert-info .cert-details {
    display: flex;
    flex-wrap: wrap;
    gap: 4px 16px;
    font-size: 13px;
    color: var(--text-muted);
    border-top: 1px solid var(--border-light);
    padding-top: 12px;
    margin-top: auto;
}
.cert-card .cert-info .cert-details span {
    display: flex;
    align-items: center;
    gap: 4px;
}
.cert-card .cert-info .cert-details i {
    color: var(--primary);
    font-size: 13px;
    width: 16px;
    text-align: center;
}
.cert-card .cert-info .cert-details .label {
    color: var(--text-light);
    font-weight: 400;
}

/* 证书名称 */
.cert-card .cert-info .cert-name {
    font-size: 17px;
    font-weight: 700;
    color: var(--secondary);
    letter-spacing: 0.3px;
    margin-bottom: 4px;
    line-height: 1.4;
}
.cert-card .cert-info .cert-sub {
    font-size: 13px;
    color: var(--text-muted);
    font-weight: 400;
    margin-bottom: 10px;
}

/* 证书卡片（内页专用，比首页更丰富） */
.cert-card .cert-info {
    text-align: left;
    padding: 18px 20px 22px;
}

/* 空状态 */
.no-cases,
.no-certs {
    text-align: center;
    padding: 60px 20px;
    color: var(--text-light);
}
.no-cases i,
.no-certs i {
    font-size: 48px;
    margin-bottom: 16px;
    display: block;
    opacity: 0.3;
}

/* ============================================
   18. 分页
   ============================================ */
.pagination {
    display: flex;
    justify-content: center;
    gap: 8px;
    padding: 20px 0;
    flex-wrap: wrap;
}
.pagination a,
.pagination span {
    display: inline-block;
    padding: 6px 16px;
    border: 1px solid var(--border-light);
    border-radius: 6px;
    font-size: 14px;
    color: var(--text-muted);
    transition: var(--transition);
    min-width: 40px;
    text-align: center;
}
.pagination a:hover {
    background: var(--primary);
    color: #fff;
    border-color: var(--primary);
}
.pagination .current {
    background: var(--primary);
    color: #fff;
    border-color: var(--primary);
}

/* ============================================
   19. 页脚
   ============================================ */
.footer {
    background: var(--secondary);
    color: rgba(255, 255, 255, 0.7);
    padding: 32px 0 28px;
    text-align: center;
    font-size: 14px;
    line-height: 2;
    border-top: 3px solid var(--primary);
}
.footer a {
    color: rgba(255, 255, 255, 0.6);
    transition: var(--transition);
}
.footer a:hover {
    color: #fff;
}
.footer .social-icons {
    display: flex;
    justify-content: center;
    gap: 18px;
    margin-bottom: 14px;
}
.footer .social-icons a {
    font-size: 20px;
    color: rgba(255, 255, 255, 0.4);
    transition: var(--transition);
}
.footer .social-icons a:hover {
    color: var(--primary);
    transform: translateY(-2px);
}

/* ============================================
   20. 产品页面独有样式（左侧分类 + 右侧内容）
   ============================================ */

/* 布局：左侧分类目录 + 右侧内容 */
.product-layout {
    display: flex;
    flex-wrap: wrap;
    gap: 40px;
    margin-top: 10px;
}

/* 左侧分类目录 */
.product-sidebar {
    flex: 0 0 240px;
    background: var(--bg-white);
    border-radius: var(--radius);
    border: 1px solid var(--border-light);
    overflow: hidden;
    align-self: flex-start;
    position: sticky;
    top: 80px;
    box-shadow: var(--shadow-sm);
}
.product-sidebar .sidebar-title {
    background: var(--secondary);
    color: #fff;
    padding: 14px 20px;
    font-size: 16px;
    font-weight: 700;
    letter-spacing: 0.5px;
    display: flex;
    align-items: center;
    gap: 10px;
}
.product-sidebar .sidebar-title i {
    color: var(--primary);
}
.product-sidebar .cat-list {
    padding: 4px 0;
}
.product-sidebar .cat-list li {
    border-bottom: 1px solid var(--border-light);
}
.product-sidebar .cat-list li:last-child {
    border-bottom: none;
}
.product-sidebar .cat-list a {
    display: block;
    padding: 12px 20px;
    font-size: 14px;
    font-weight: 500;
    color: var(--text-muted);
    transition: var(--transition);
    border-left: 3px solid transparent;
}
.product-sidebar .cat-list a:hover,
.product-sidebar .cat-list a.active {
    color: var(--primary);
    background: rgba(211, 84, 42, 0.05);
    border-left-color: var(--primary);
    padding-left: 24px;
}
.product-sidebar .cat-list a i {
    margin-right: 10px;
    width: 18px;
    text-align: center;
    color: var(--primary);
    font-size: 14px;
}

/* 右侧主内容 */
.product-main {
    flex: 1;
    min-width: 0;
}
.product-category-header {
    margin-bottom: 24px;
}
.product-category-header h2 {
    font-size: 24px;
    font-weight: 700;
    color: var(--secondary);
    display: flex;
    align-items: center;
    gap: 12px;
}
.product-category-header h2 i {
    color: var(--primary);
}
.product-category-header p {
    color: var(--text-muted);
    font-size: 14px;
    margin-top: 4px;
}
.product-category-header .product-count {
    font-size: 14px;
    color: var(--text-light);
    font-weight: 400;
    margin-left: auto;
}

/* ★ 产品卡片增强 - 图片已使用 4:3 比例（见第9节） */
.product-card .product-img .category-badge {
    position: absolute;
    top: 10px;
    right: 10px;
    background: rgba(30, 42, 58, 0.8);
    color: #fff;
    font-size: 11px;
    padding: 3px 12px;
    border-radius: 20px;
    letter-spacing: 0.3px;
    backdrop-filter: blur(4px);
}
.product-card .product-info {
    padding: 14px 16px 18px;
    text-align: center;
}
.product-card .product-info .product-tag {
    display: inline-block;
    font-size: 11px;
    font-weight: 600;
    color: var(--primary);
    background: rgba(211, 84, 42, 0.08);
    padding: 2px 14px;
    border-radius: 20px;
    margin-top: 4px;
}
.product-card .product-info .product-desc {
    font-size: 13px;
    color: var(--text-light);
    margin-top: 6px;
    line-height: 1.5;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

/* 实力展示 */
.strength-section {
    margin-top: 50px;
    padding-top: 40px;
    border-top: 2px solid var(--border-light);
}
.strength-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 24px;
    margin-top: 16px;
}
.strength-item {
    text-align: center;
    padding: 28px 16px 24px;
    background: var(--bg-light);
    border-radius: var(--radius);
    transition: var(--transition);
    border: 1px solid transparent;
}
.strength-item:hover {
    border-color: var(--primary);
    box-shadow: var(--shadow-sm);
    background: #fff;
    transform: translateY(-4px);
}
.strength-item .num {
    font-size: 38px;
    font-weight: 800;
    color: var(--primary);
    line-height: 1.2;
}
.strength-item .num span {
    font-size: 20px;
    font-weight: 400;
}
.strength-item h4 {
    font-size: 16px;
    font-weight: 600;
    color: var(--secondary);
    margin-top: 6px;
}
.strength-item p {
    font-size: 13px;
    color: var(--text-muted);
    margin-top: 4px;
}

/* 联系方式条 */
.contact-bar {
    margin-top: 40px;
    background: var(--bg-light);
    border-radius: var(--radius);
    padding: 30px 40px;
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    justify-content: space-between;
    gap: 20px;
    border: 1px solid var(--border-light);
}
.contact-bar .contact-item {
    display: flex;
    align-items: center;
    gap: 12px;
}
.contact-bar .contact-item i {
    font-size: 28px;
    color: var(--primary);
    width: 40px;
    text-align: center;
}
.contact-bar .contact-item .label {
    font-size: 13px;
    color: var(--text-light);
}
.contact-bar .contact-item .value {
    font-size: 18px;
    font-weight: 700;
    color: var(--secondary);
}
.contact-bar .contact-item .value a {
    color: var(--secondary);
    transition: var(--transition);
}
.contact-bar .contact-item .value a:hover {
    color: var(--primary);
}

/* 产品页面响应式 */
@media (max-width: 992px) {
    .product-sidebar {
        flex: 0 0 200px;
    }
}
@media (max-width: 768px) {
    .product-layout {
        flex-direction: column;
    }
    .product-sidebar {
        flex: 1 1 100%;
        position: static;
        top: auto;
    }
    .product-sidebar .cat-list {
        display: flex;
        flex-wrap: wrap;
        padding: 8px;
    }
    .product-sidebar .cat-list li {
        border-bottom: none;
        flex: 1 1 45%;
    }
    .product-sidebar .cat-list a {
        padding: 8px 14px;
        font-size: 13px;
        border-left: none;
        border-radius: 6px;
        text-align: center;
    }
    .product-sidebar .cat-list a:hover,
    .product-sidebar .cat-list a.active {
        padding-left: 14px;
        background: rgba(211, 84, 42, 0.08);
        border-left: none;
    }
    .contact-bar {
        flex-direction: column;
        align-items: flex-start;
        padding: 20px;
    }
}
@media (max-width: 480px) {
    .product-sidebar .cat-list li {
        flex: 1 1 100%;
    }
    .contact-bar .contact-item .value {
        font-size: 15px;
    }
}