/* ========== 全局重置 ========== */
*, *::before, *::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary: #009688;
    --primary-dark: #00796B;
    --primary-light: #4DB6AC;
    --primary-lighter: #E0F2F1;
    --accent: #FF6F00;
    --text-dark: #263238;
    --text-body: #455A64;
    --text-light: #78909C;
    --bg-white: #ffffff;
    --bg-light: #F5F7FA;
    --bg-gray: #ECEFF1;
    --border-color: #CFD8DC;
    --shadow-sm: 0 2px 4px rgba(0,0,0,0.06);
    --shadow-md: 0 4px 16px rgba(0,0,0,0.10);
    --shadow-lg: 0 8px 32px rgba(0,0,0,0.12);
    --transition: all 0.3s ease;
    --radius: 8px;
    --radius-lg: 16px;
    --max-width: 1280px;
}

html {
    scroll-behavior: smooth;
    font-size: 16px;
}

body {
    font-family: "Microsoft YaHei", "PingFang SC", "Helvetica Neue", Arial, sans-serif;
    color: var(--text-body);
    line-height: 1.7;
    background: var(--bg-white);
    overflow-x: hidden;
}

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

a:hover {
    color: var(--primary-dark);
}

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

ul {
    list-style: none;
}

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

/* ========== 顶部公告栏 ========== */
.top-bar {
    background: var(--primary-dark);
    color: #fff;
    font-size: 0.85rem;
    padding: 6px 0;
}

.top-bar .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 8px;
}

.top-bar .contact-info span {
    margin-right: 20px;
    display: inline-flex;
    align-items: center;
    gap: 6px;
}

.top-bar .contact-info i {
    font-size: 0.8rem;
}

.top-bar .social-links a {
    color: #fff;
    margin-left: 12px;
    font-size: 0.85rem;
    opacity: 0.85;
}

.top-bar .social-links a:hover {
    opacity: 1;
}

/* ========== 导航栏 ========== */
.header {
    background: #fff;
    box-shadow: var(--shadow-sm);
    position: sticky;
    top: 0;
    z-index: 1000;
    transition: var(--transition);
}

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

.navbar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 72px;
}

.nav-logo {
    display: flex;
    align-items: center;
    gap: 12px;
    font-size: 1.3rem;
    font-weight: 700;
    color: var(--primary-dark);
}

.nav-logo .logo-icon {
    width: 44px;
    height: 44px;
    background: linear-gradient(135deg, var(--primary), var(--primary-dark));
    border-radius: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: #fff;
    font-size: 1.4rem;
    font-weight: 700;
}

.nav-logo .logo-text {
    line-height: 1.2;
}

.nav-logo .logo-text small {
    display: block;
    font-size: 0.7rem;
    font-weight: 400;
    color: var(--text-light);
    letter-spacing: 1px;
}

.nav-menu {
    display: flex;
    align-items: center;
    gap: 4px;
}

.nav-menu > li {
    position: relative;
}

.nav-menu > li > a {
    display: block;
    padding: 10px 16px;
    color: var(--text-dark);
    font-size: 0.95rem;
    font-weight: 500;
    border-radius: var(--radius);
    transition: var(--transition);
}

.nav-menu > li > a:hover,
.nav-menu > li > a.active {
    color: var(--primary);
    background: var(--primary-lighter);
}

.nav-menu > li > a::after {
    content: '';
    position: absolute;
    bottom: 4px;
    left: 50%;
    transform: translateX(-50%);
    width: 0;
    height: 2px;
    background: var(--primary);
    transition: var(--transition);
}

.nav-menu > li > a:hover::after,
.nav-menu > li > a.active::after {
    width: 60%;
}

/* 下拉菜单 */
.dropdown {
    position: absolute;
    top: 100%;
    left: 0;
    min-width: 240px;
    background: #fff;
    box-shadow: var(--shadow-lg);
    border-radius: var(--radius);
    padding: 8px 0;
    opacity: 0;
    visibility: hidden;
    transform: translateY(10px);
    transition: var(--transition);
    z-index: 1001;
}

.nav-menu > li:hover .dropdown {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.dropdown li a {
    display: block;
    padding: 8px 20px;
    color: var(--text-body);
    font-size: 0.88rem;
    transition: var(--transition);
}

.dropdown li a:hover {
    background: var(--primary-lighter);
    color: var(--primary-dark);
    padding-left: 24px;
}

.dropdown .dropdown-label {
    padding: 6px 20px;
    font-size: 0.75rem;
    font-weight: 700;
    color: var(--text-light);
    text-transform: uppercase;
    letter-spacing: 1px;
}

.dropdown .dropdown-divider {
    height: 1px;
    background: var(--border-color);
    margin: 4px 0;
}

/* 移动端菜单按钮 */
.nav-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    cursor: pointer;
    padding: 8px;
}

.nav-toggle span {
    width: 26px;
    height: 3px;
    background: var(--text-dark);
    border-radius: 2px;
    transition: var(--transition);
}

.nav-toggle.active span:nth-child(1) {
    transform: rotate(45deg) translate(6px, 6px);
}
.nav-toggle.active span:nth-child(2) {
    opacity: 0;
}
.nav-toggle.active span:nth-child(3) {
    transform: rotate(-45deg) translate(6px, -6px);
}

/* ========== Hero 区域 ========== */
.hero {
    position: relative;
    background: linear-gradient(135deg, var(--primary-dark) 0%, var(--primary) 50%, var(--primary-light) 100%);
    color: #fff;
    padding: 80px 0 100px;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: -50%;
    right: -10%;
    width: 600px;
    height: 600px;
    background: rgba(255,255,255,0.05);
    border-radius: 50%;
}

.hero::after {
    content: '';
    position: absolute;
    bottom: -30%;
    left: -5%;
    width: 400px;
    height: 400px;
    background: rgba(255,255,255,0.03);
    border-radius: 50%;
}

.hero-content {
    position: relative;
    z-index: 2;
    max-width: 720px;
}

.hero-badge {
    display: inline-block;
    background: rgba(255,255,255,0.15);
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255,255,255,0.3);
    padding: 6px 18px;
    border-radius: 30px;
    font-size: 0.85rem;
    font-weight: 500;
    margin-bottom: 20px;
}

.hero h1 {
    font-size: 2.8rem;
    font-weight: 700;
    line-height: 1.25;
    margin-bottom: 16px;
}

.hero h1 span {
    color: #B2DFDB;
}

.hero-subtitle {
    font-size: 1.15rem;
    line-height: 1.8;
    opacity: 0.92;
    margin-bottom: 32px;
}

.hero-buttons {
    display: flex;
    gap: 16px;
    flex-wrap: wrap;
}

.btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 12px 32px;
    border-radius: var(--radius);
    font-size: 0.95rem;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    border: 2px solid transparent;
}

.btn-primary {
    background: #fff;
    color: var(--primary-dark);
}

.btn-primary:hover {
    background: var(--primary-lighter);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.btn-outline {
    background: transparent;
    color: #fff;
    border-color: rgba(255,255,255,0.5);
}

.btn-outline:hover {
    background: rgba(255,255,255,0.1);
    border-color: #fff;
}

.btn-accent {
    background: var(--accent);
    color: #fff;
}

.btn-accent:hover {
    background: #E65100;
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

/* Hero 统计数据 */
.hero-stats {
    position: relative;
    z-index: 2;
    display: flex;
    gap: 48px;
    margin-top: 56px;
    flex-wrap: wrap;
}

.hero-stat .stat-num {
    font-size: 2.5rem;
    font-weight: 700;
    line-height: 1;
}

.hero-stat .stat-label {
    font-size: 0.9rem;
    opacity: 0.85;
    margin-top: 4px;
}

/* ========== 通用区块 ========== */
.section {
    padding: 80px 0;
}

.section-light {
    background: var(--bg-light);
}

.section-header {
    text-align: center;
    max-width: 720px;
    margin: 0 auto 56px;
}

.section-header h2 {
    font-size: 2rem;
    font-weight: 700;
    color: var(--text-dark);
    margin-bottom: 12px;
}

.section-header .subtitle {
    font-size: 1.05rem;
    color: var(--text-light);
}

.section-header .divider {
    width: 60px;
    height: 4px;
    background: var(--primary);
    border-radius: 2px;
    margin: 16px auto 0;
}

/* ========== 产品卡片网格 ========== */
.products-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 28px;
}

.product-card {
    background: #fff;
    border-radius: var(--radius-lg);
    overflow: hidden;
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
    border: 1px solid var(--border-color);
}

.product-card:hover {
    transform: translateY(-6px);
    box-shadow: var(--shadow-lg);
    border-color: var(--primary-light);
}

.product-card .card-icon {
    height: 160px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, var(--primary-lighter), #fff);
    font-size: 3.5rem;
    color: var(--primary);
}

.product-card .card-body {
    padding: 24px;
}

.product-card .card-body h3 {
    font-size: 1.2rem;
    font-weight: 600;
    color: var(--text-dark);
    margin-bottom: 8px;
}

.product-card .card-body p {
    font-size: 0.9rem;
    color: var(--text-body);
    line-height: 1.7;
    margin-bottom: 16px;
}

.product-card .card-link {
    font-size: 0.88rem;
    font-weight: 600;
    color: var(--primary);
    display: inline-flex;
    align-items: center;
    gap: 6px;
}

.product-card .card-link:hover {
    gap: 10px;
}

/* ========== 公司介绍区 ========== */
.about-preview {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 56px;
    align-items: center;
}

.about-preview-text h2 {
    font-size: 2rem;
    font-weight: 700;
    color: var(--text-dark);
    margin-bottom: 16px;
}

.about-preview-text p {
    font-size: 1rem;
    line-height: 1.9;
    margin-bottom: 16px;
}

.about-features {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 20px;
    margin-top: 28px;
}

.about-feature {
    display: flex;
    align-items: flex-start;
    gap: 12px;
}

.about-feature .feature-icon {
    width: 44px;
    height: 44px;
    min-width: 44px;
    background: var(--primary-lighter);
    border-radius: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.3rem;
    color: var(--primary);
}

.about-feature .feature-text h4 {
    font-size: 0.95rem;
    font-weight: 600;
    color: var(--text-dark);
    margin-bottom: 2px;
}

.about-feature .feature-text p {
    font-size: 0.82rem;
    color: var(--text-light);
    margin: 0;
}

.about-preview-image {
    position: relative;
}

.about-preview-image .img-placeholder {
    width: 100%;
    aspect-ratio: 4/3;
    background: linear-gradient(135deg, var(--primary-lighter), var(--primary-light));
    border-radius: var(--radius-lg);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 5rem;
    color: rgba(255,255,255,0.6);
}

/* 首页「关于」区块产品实拍图 */
.about-preview-image .about-photo {
    width: 100%;
    height: auto;
    aspect-ratio: 4/3;
    object-fit: cover;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
    display: block;
}

.about-preview-image .floating-badge {
    position: absolute;
    bottom: -20px;
    left: -20px;
    background: #fff;
    padding: 16px 24px;
    border-radius: var(--radius);
    box-shadow: var(--shadow-lg);
    display: flex;
    align-items: center;
    gap: 12px;
}

.floating-badge .badge-num {
    font-size: 2rem;
    font-weight: 700;
    color: var(--primary);
    line-height: 1;
}

.floating-badge .badge-text {
    font-size: 0.82rem;
    color: var(--text-body);
    line-height: 1.4;
}

/* ========== 认证徽章区 ========== */
.cert-badges {
    display: flex;
    justify-content: center;
    gap: 40px;
    flex-wrap: wrap;
}

.cert-badge {
    text-align: center;
    padding: 24px 32px;
    background: #fff;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
    border: 2px solid var(--border-color);
    transition: var(--transition);
    min-width: 180px;
}

.cert-badge:hover {
    border-color: var(--primary);
    transform: translateY(-4px);
    box-shadow: var(--shadow-md);
}

.cert-badge .cert-icon {
    width: 64px;
    height: 64px;
    margin: 0 auto 12px;
    background: var(--primary-lighter);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.8rem;
    color: var(--primary);
}

.cert-badge h4 {
    font-size: 1rem;
    font-weight: 600;
    color: var(--text-dark);
}

.cert-badge p {
    font-size: 0.8rem;
    color: var(--text-light);
    margin-top: 4px;
}

/* ========== 化合物材料区 ========== */
.compounds-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 24px;
}

.compound-card {
    background: #fff;
    border-radius: var(--radius);
    padding: 28px;
    box-shadow: var(--shadow-sm);
    border-left: 4px solid var(--primary);
    transition: var(--transition);
}

.compound-card:hover {
    box-shadow: var(--shadow-md);
    transform: translateX(4px);
}

.compound-card h4 {
    font-size: 1.15rem;
    font-weight: 600;
    color: var(--primary-dark);
    margin-bottom: 8px;
    display: flex;
    align-items: center;
    gap: 8px;
}

.compound-card .compound-tag {
    display: inline-block;
    font-size: 0.72rem;
    font-weight: 600;
    padding: 2px 10px;
    border-radius: 20px;
    background: var(--primary-lighter);
    color: var(--primary-dark);
    margin-bottom: 12px;
}

.compound-card p {
    font-size: 0.88rem;
    color: var(--text-body);
    line-height: 1.7;
}

.compound-card .temp-range {
    margin-top: 12px;
    font-size: 0.82rem;
    color: var(--text-light);
    padding-top: 12px;
    border-top: 1px solid var(--border-color);
}

/* ========== 行业服务区 ========== */
.industries-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
    gap: 20px;
}

.industry-card {
    background: #fff;
    border-radius: var(--radius);
    padding: 32px 20px;
    text-align: center;
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
    border: 1px solid var(--border-color);
}

.industry-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-md);
    border-color: var(--primary-light);
    background: var(--primary-lighter);
}

.industry-card .industry-icon {
    font-size: 2.5rem;
    margin-bottom: 12px;
}

.industry-card h4 {
    font-size: 0.95rem;
    font-weight: 600;
    color: var(--text-dark);
}

/* ========== 新闻活动区 ========== */
.news-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 28px;
}

.news-card {
    background: #fff;
    border-radius: var(--radius-lg);
    overflow: hidden;
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
    border: 1px solid var(--border-color);
}

.news-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-md);
}

.news-card .news-date {
    background: var(--primary);
    color: #fff;
    padding: 16px 20px;
    text-align: center;
}

.news-card .news-date .day {
    font-size: 1.6rem;
    font-weight: 700;
    line-height: 1;
}

.news-card .news-date .month {
    font-size: 0.82rem;
    margin-top: 4px;
    opacity: 0.9;
}

.news-card .news-body {
    padding: 20px;
}

.news-card .news-body h4 {
    font-size: 1rem;
    font-weight: 600;
    color: var(--text-dark);
    margin-bottom: 8px;
}

.news-card .news-body p {
    font-size: 0.85rem;
    color: var(--text-body);
    line-height: 1.6;
}

.news-card .news-tag {
    display: inline-block;
    font-size: 0.72rem;
    font-weight: 600;
    padding: 2px 10px;
    border-radius: 20px;
    background: var(--primary-lighter);
    color: var(--primary-dark);
    margin-top: 12px;
}

/* ========== 联系表单区 ========== */
.contact-section {
    display: grid;
    grid-template-columns: 1fr 1.2fr;
    gap: 48px;
}

.contact-info-card {
    background: linear-gradient(135deg, var(--primary-dark), var(--primary));
    color: #fff;
    border-radius: var(--radius-lg);
    padding: 40px;
}

.contact-info-card h3 {
    font-size: 1.5rem;
    margin-bottom: 24px;
}

.contact-info-list li {
    display: flex;
    align-items: flex-start;
    gap: 14px;
    margin-bottom: 20px;
}

.contact-info-list .info-icon {
    width: 40px;
    height: 40px;
    min-width: 40px;
    background: rgba(255,255,255,0.15);
    border-radius: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.1rem;
}

.contact-info-list .info-text {
    font-size: 0.92rem;
    line-height: 1.6;
}

.contact-info-list .info-text strong {
    display: block;
    font-size: 0.8rem;
    opacity: 0.8;
    margin-bottom: 2px;
}

.contact-form-card {
    background: #fff;
    border-radius: var(--radius-lg);
    padding: 40px;
    box-shadow: var(--shadow-md);
}

.contact-form-card h3 {
    font-size: 1.5rem;
    color: var(--text-dark);
    margin-bottom: 24px;
}

.form-group {
    margin-bottom: 20px;
}

.form-group label {
    display: block;
    font-size: 0.88rem;
    font-weight: 600;
    color: var(--text-dark);
    margin-bottom: 6px;
}

.form-group label .required {
    color: #e53935;
}

.form-group input,
.form-group select,
.form-group textarea {
    width: 100%;
    padding: 10px 14px;
    border: 1.5px solid var(--border-color);
    border-radius: var(--radius);
    font-size: 0.92rem;
    font-family: inherit;
    transition: var(--transition);
    background: var(--bg-light);
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--primary);
    background: #fff;
    box-shadow: 0 0 0 3px rgba(0,150,136,0.1);
}

.form-group textarea {
    resize: vertical;
    min-height: 120px;
}

.form-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 20px;
}

/* ========== 页面横幅 ========== */
.page-banner {
    background: linear-gradient(135deg, var(--primary-dark), var(--primary));
    color: #fff;
    padding: 60px 0 50px;
    text-align: center;
    position: relative;
    overflow: hidden;
}

.page-banner::before {
    content: '';
    position: absolute;
    top: -30%;
    right: -10%;
    width: 400px;
    height: 400px;
    background: rgba(255,255,255,0.05);
    border-radius: 50%;
}

.page-banner h1 {
    font-size: 2.2rem;
    font-weight: 700;
    position: relative;
    z-index: 2;
}

.page-banner .breadcrumb {
    position: relative;
    z-index: 2;
    margin-top: 12px;
    font-size: 0.88rem;
    opacity: 0.85;
}

.page-banner .breadcrumb a {
    color: rgba(255,255,255,0.8);
}

.page-banner .breadcrumb a:hover {
    color: #fff;
}

.page-banner .breadcrumb span {
    margin: 0 8px;
    opacity: 0.6;
}

/* ========== 内容区通用 ========== */
.content-section {
    padding: 64px 0;
}

.content-block {
    max-width: 860px;
    margin: 0 auto;
}

.content-block h2 {
    font-size: 1.6rem;
    font-weight: 700;
    color: var(--text-dark);
    margin: 32px 0 16px;
}

.content-block h2:first-child {
    margin-top: 0;
}

.content-block h3 {
    font-size: 1.2rem;
    font-weight: 600;
    color: var(--primary-dark);
    margin: 24px 0 12px;
}

.content-block p {
    font-size: 1rem;
    line-height: 1.9;
    margin-bottom: 16px;
}

.content-block ul {
    margin: 16px 0 16px 20px;
}

.content-block ul li {
    font-size: 0.95rem;
    line-height: 2;
    position: relative;
    padding-left: 20px;
}

.content-block ul li::before {
    content: '▶';
    position: absolute;
    left: 0;
    color: var(--primary);
    font-size: 0.7rem;
    top: 4px;
}

.content-block .quote {
    border-left: 4px solid var(--primary);
    padding: 16px 24px;
    background: var(--primary-lighter);
    border-radius: 0 var(--radius) var(--radius) 0;
    margin: 24px 0;
    font-style: italic;
    color: var(--text-dark);
}

/* ========== 产品分类详情 ========== */
.product-category {
    margin-bottom: 56px;
}

.product-category-header {
    display: flex;
    align-items: center;
    gap: 16px;
    margin-bottom: 24px;
    padding-bottom: 16px;
    border-bottom: 2px solid var(--primary-lighter);
}

.product-category-header .cat-icon {
    width: 56px;
    height: 56px;
    min-width: 56px;
    background: var(--primary-lighter);
    border-radius: var(--radius);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.8rem;
    color: var(--primary);
}

.product-category-header h2 {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-dark);
}

.product-category-header p {
    font-size: 0.88rem;
    color: var(--text-light);
}

.product-items {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
    gap: 16px;
}

.product-item {
    background: #fff;
    border: 1px solid var(--border-color);
    border-radius: var(--radius);
    padding: 20px;
    transition: var(--transition);
}

.product-item:hover {
    border-color: var(--primary-light);
    box-shadow: var(--shadow-sm);
    transform: translateY(-2px);
}

.product-item h4 {
    font-size: 0.98rem;
    font-weight: 600;
    color: var(--text-dark);
    margin-bottom: 6px;
    display: flex;
    align-items: center;
    gap: 6px;
}

.product-item p {
    font-size: 0.84rem;
    color: var(--text-light);
    line-height: 1.6;
}

/* 产品配图卡片（图 + 信息） */
.pd-card {
    display: block;
    padding: 0;
    background: #fff;
    border: 1px solid var(--border-color);
    border-radius: 12px;
    overflow: hidden;
    transition: transform 0.3s ease, box-shadow 0.3s ease, border-color 0.3s ease;
}
.pd-card:hover {
    transform: translateY(-3px);
    border-color: var(--primary-light);
    box-shadow: 0 8px 24px rgba(0, 150, 136, 0.15);
}
.pd-card .pd-card-img {
    position: relative;
    width: 100%;
    height: 180px;
    background: linear-gradient(135deg, var(--primary-lighter), #f4fafa);
    overflow: hidden;
    display: flex;
    align-items: center;
    justify-content: center;
}
.pd-card .pd-card-img img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.5s ease;
}
.pd-card:hover .pd-card-img img {
    transform: scale(1.06);
}
.pd-card .pd-card-placeholder {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 6px;
    width: 100%;
    height: 100%;
    color: var(--primary);
    text-align: center;
    padding: 12px;
}
.pd-card .pd-card-placeholder .ph-icon {
    font-size: 2.6rem;
    line-height: 1;
    opacity: 0.55;
}
.pd-card .pd-card-placeholder .ph-text {
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--primary-dark);
    opacity: 0.7;
    max-width: 90%;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

/* ========== 时间线（公司历史） ========== */
.timeline {
    position: relative;
    max-width: 800px;
    margin: 0 auto;
    padding: 20px 0;
}

.timeline::before {
    content: '';
    position: absolute;
    left: 30px;
    top: 0;
    bottom: 0;
    width: 3px;
    background: var(--primary-lighter);
}

.timeline-item {
    position: relative;
    padding-left: 80px;
    margin-bottom: 40px;
}

.timeline-item::before {
    content: '';
    position: absolute;
    left: 22px;
    top: 4px;
    width: 18px;
    height: 18px;
    background: var(--primary);
    border: 4px solid #fff;
    border-radius: 50%;
    box-shadow: 0 0 0 3px var(--primary-lighter);
}

.timeline-item .timeline-year {
    font-size: 1.3rem;
    font-weight: 700;
    color: var(--primary);
    margin-bottom: 4px;
}

.timeline-item .timeline-content h4 {
    font-size: 1.05rem;
    font-weight: 600;
    color: var(--text-dark);
    margin-bottom: 6px;
}

.timeline-item .timeline-content p {
    font-size: 0.9rem;
    color: var(--text-body);
    line-height: 1.7;
}

/* ========== CTA 区域 ========== */
.cta-section {
    background: linear-gradient(135deg, var(--primary-dark), var(--primary));
    color: #fff;
    padding: 64px 0;
    text-align: center;
    position: relative;
    overflow: hidden;
}

.cta-section::before {
    content: '';
    position: absolute;
    top: -50%;
    right: -10%;
    width: 500px;
    height: 500px;
    background: rgba(255,255,255,0.04);
    border-radius: 50%;
}

.cta-section h2 {
    font-size: 2rem;
    font-weight: 700;
    margin-bottom: 12px;
    position: relative;
    z-index: 2;
}

.cta-section p {
    font-size: 1.05rem;
    opacity: 0.9;
    margin-bottom: 28px;
    position: relative;
    z-index: 2;
}

.cta-section .btn {
    position: relative;
    z-index: 2;
}

/* ========== 页脚 ========== */
.footer {
    background: #1a1f23;
    color: #a0aab4;
    padding: 64px 0 0;
}

.footer-grid {
    display: grid;
    grid-template-columns: 1.5fr 1fr 1fr 1fr;
    gap: 40px;
    margin-bottom: 48px;
}

.footer-brand .nav-logo {
    color: #fff;
    margin-bottom: 16px;
}

.footer-brand p {
    font-size: 0.88rem;
    line-height: 1.8;
    margin-bottom: 16px;
}

.footer-brand .footer-contact li {
    font-size: 0.84rem;
    margin-bottom: 8px;
    display: flex;
    align-items: flex-start;
    gap: 8px;
}

.footer-brand .footer-contact i {
    color: var(--primary-light);
    margin-top: 2px;
}

.footer-col h4 {
    color: #fff;
    font-size: 1rem;
    font-weight: 600;
    margin-bottom: 20px;
    position: relative;
    padding-bottom: 12px;
}

.footer-col h4::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 30px;
    height: 2px;
    background: var(--primary);
}

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

.footer-col ul li a {
    color: #a0aab4;
    font-size: 0.86rem;
    transition: var(--transition);
}

.footer-col ul li a:hover {
    color: var(--primary-light);
    padding-left: 4px;
}

.footer-bottom {
    border-top: 1px solid rgba(255,255,255,0.1);
    padding: 24px 0;
    text-align: center;
    font-size: 0.82rem;
}

.footer-bottom p {
    margin-bottom: 4px;
}

.footer-bottom a {
    color: var(--primary-light);
}

/* ========== 返回顶部 ========== */
.back-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 48px;
    height: 48px;
    background: var(--primary);
    color: #fff;
    border: none;
    border-radius: 50%;
    cursor: pointer;
    font-size: 1.3rem;
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    visibility: hidden;
    transition: var(--transition);
    box-shadow: var(--shadow-md);
    z-index: 999;
}

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

.back-to-top:hover {
    background: var(--primary-dark);
    transform: translateY(-4px);
}

/* ========== 响应式 ========== */
@media (max-width: 1024px) {
    .footer-grid {
        grid-template-columns: 1fr 1fr;
    }
    .about-preview {
        gap: 32px;
    }
}

@media (max-width: 768px) {
    .nav-menu {
        position: fixed;
        top: 72px;
        left: 0;
        right: 0;
        background: #fff;
        flex-direction: column;
        align-items: stretch;
        padding: 16px;
        box-shadow: var(--shadow-lg);
        max-height: 0;
        overflow: hidden;
        transition: max-height 0.4s ease;
    }

    .nav-menu.active {
        max-height: 80vh;
        overflow-y: auto;
    }

    .nav-menu > li {
        width: 100%;
    }

    .nav-menu > li > a {
        padding: 12px 16px;
        border-bottom: 1px solid var(--border-color);
    }

    .dropdown {
        position: static;
        opacity: 1;
        visibility: visible;
        transform: none;
        box-shadow: none;
        padding-left: 20px;
        max-height: 0;
        overflow: hidden;
        transition: max-height 0.3s ease;
    }

    .nav-menu > li:hover .dropdown {
        max-height: 500px;
    }

    .nav-toggle {
        display: flex;
    }

    .hero h1 {
        font-size: 2rem;
    }

    .hero-subtitle {
        font-size: 1rem;
    }

    .hero-stats {
        gap: 28px;
    }

    .hero-stat .stat-num {
        font-size: 1.8rem;
    }

    .section {
        padding: 56px 0;
    }

    .section-header h2 {
        font-size: 1.6rem;
    }

    .about-preview,
    .contact-section {
        grid-template-columns: 1fr;
    }

    .form-row {
        grid-template-columns: 1fr;
    }

    .footer-grid {
        grid-template-columns: 1fr;
        gap: 32px;
    }

    .cert-badges {
        gap: 16px;
    }

    .about-features {
        grid-template-columns: 1fr;
    }

    .top-bar {
        font-size: 0.78rem;
    }

    .top-bar .container {
        justify-content: center;
        text-align: center;
    }

    .page-banner h1 {
        font-size: 1.6rem;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 16px;
    }

    .hero {
        padding: 48px 0 64px;
    }

    .hero h1 {
        font-size: 1.6rem;
    }

    .hero-buttons {
        flex-direction: column;
    }

    .hero-buttons .btn {
        width: 100%;
        justify-content: center;
    }

    .hero-stats {
        flex-direction: column;
        gap: 20px;
    }

    .products-grid,
    .compounds-grid,
    .news-grid {
        grid-template-columns: 1fr;
    }

    .contact-info-card,
    .contact-form-card {
        padding: 24px;
    }
}