/* ================= 基础重置与变量定义 ================= */
:root {
    --primary-color: #0A2540; /* 深邃工业蓝 */
    --accent-color: #0077FF; /* 现代高亮蓝 */
    --text-main: #333333;
    --text-muted: #6B7280;
    --bg-light: #F9FAFB;
    --white: #FFFFFF;
    --border-radius: 8px;
    --transition: all 0.3s ease;
}

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

body {
    font-family: 'Inter', sans-serif;
    color: var(--text-main);
    background-color: var(--white);
    line-height: 1.6;
}

/* ================= 通用按钮规范 ================= */
.btn {
    display: inline-block;
    padding: 12px 24px;
    border-radius: var(--border-radius);
    text-decoration: none;
    font-weight: 600;
    font-size: 0.95rem;
    transition: var(--transition);
    cursor: pointer;
}

.btn-primary { background-color: var(--accent-color); color: var(--white); border: 2px solid var(--accent-color); }
.btn-primary:hover { background-color: #005CE6; border-color: #005CE6; }

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

.btn-outline { background-color: transparent; color: var(--primary-color); border: 1px solid var(--primary-color); padding: 8px 16px; font-size: 0.85rem; }
.btn-outline:hover { background-color: var(--primary-color); color: var(--white); }

.btn-download { background-color: var(--bg-light); color: var(--text-main); border: 1px solid #E5E7EB; padding: 8px 16px; font-size: 0.85rem; }
.btn-download:hover { background-color: #E5E7EB; }

.w-100 { width: 100%; text-align: center; margin-bottom: 12px; display: block; }
.w-100:last-child { margin-bottom: 0; }
.mt-20 { margin-top: 20px; }
.mt-40 { margin-top: 40px; }
.text-center { text-align: center; }

/* ================= 导航栏 ================= */
.navbar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 20px 5%;
    background-color: var(--white);
    border-bottom: 1px solid #E5E7EB;
    position: sticky;
    top: 0;
    z-index: 100;
}

.logo { font-size: 1.5rem; font-weight: 800; letter-spacing: -0.5px; }
.logo span { color: var(--accent-color); }

.nav-links { list-style: none; display: flex; gap: 32px; }
.nav-links a { text-decoration: none; color: var(--text-main); font-weight: 600; transition: var(--transition); }
.nav-links a:hover { color: var(--accent-color); }

/* ================= 重构：沉浸式全屏 Hero 轮播区域 ================= */
.hero {
    position: relative;
    padding: 180px 5% 160px 5%;
    min-height: 80vh;
    display: flex;
    align-items: center;
    overflow: hidden;
    background-color: var(--primary-color);
}

.hero-content {
    max-width: 800px;
    position: relative;
    z-index: 10; 
    text-shadow: 0 4px 10px rgba(0, 0, 0, 0.6); 
}

.hero h1 {
    font-size: 4rem;
    line-height: 1.15;
    margin-bottom: 24px;
    letter-spacing: -1px;
    color: var(--white);
}

.hero p {
    font-size: 1.3rem;
    color: #F9FAFB;
    margin-bottom: 40px;
    max-width: 650px;
}

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

.hero-carousel {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 1;
    background-color: var(--primary-color);
}

.hero-carousel::after {
    content: '';
    position: absolute;
    top: 0; left: 0; width: 100%; height: 100%;
    background: linear-gradient(to right, rgba(10, 37, 64, 0.85) 0%, rgba(10, 37, 64, 0.3) 100%);
    pointer-events: none;
    z-index: 2;
}

.carousel-slide {
    position: absolute;
    top: 0; left: 0; width: 100%; height: 100%;
    background-size: cover;
    background-position: center;
    opacity: 0;
    transition: opacity 1s ease-in-out;
}

.carousel-slide.active { opacity: 1; }

.carousel-indicators {
    position: absolute;
    bottom: 40px;
    left: 5%;
    display: flex;
    gap: 12px;
    z-index: 10;
}

.dot {
    width: 40px; height: 4px;
    background-color: rgba(255, 255, 255, 0.3);
    border-radius: 2px;
    cursor: pointer;
    transition: var(--transition);
}

.dot.active { background-color: var(--white); }

/* ================= 严谨数据驱动的产品网格模块 ================= */
.products-section { padding: 100px 5%; background-color: var(--bg-light); }
.section-header { text-align: center; margin-bottom: 64px; }
.section-header h2 { font-size: 2.5rem; color: var(--primary-color); margin-bottom: 16px; }
.section-header p { font-size: 1.1rem; color: var(--text-muted); }

.product-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 32px;
    max-width: 1200px;
    margin: 0 auto;
}

.product-card {
    background-color: var(--white);
    border: 1px solid #E5E7EB;
    border-radius: var(--border-radius);
    padding: 32px;
    transition: var(--transition);
    display: flex;
    flex-direction: column;
}

.product-card:hover { transform: translateY(-5px); box-shadow: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04); }
.product-tag { font-size: 0.75rem; text-transform: uppercase; letter-spacing: 1px; color: var(--accent-color); font-weight: 800; margin-bottom: 12px; }
.product-title { font-size: 1.5rem; color: var(--primary-color); margin-bottom: 24px; }
.product-data { margin-bottom: 32px; flex-grow: 1; }
.product-data p { font-size: 0.95rem; color: var(--text-muted); border-bottom: 1px solid #F3F4F6; padding: 12px 0; }
.product-data p:last-child { border-bottom: none; }
.product-data strong { color: var(--text-main); display: inline-block; width: 120px; }
.product-actions { display: flex; gap: 12px; justify-content: space-between; }

/* ================= 首页新闻简讯模块 ================= */
.home-news-section { padding: 80px 5%; background-color: var(--white); }
.home-news-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); gap: 30px; max-width: 1200px; margin: 0 auto; }
.home-news-card { padding: 30px; background-color: var(--bg-light); border: 1px solid #E5E7EB; border-radius: var(--border-radius); transition: var(--transition); }
.home-news-card:hover { border-color: var(--accent-color); box-shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.1); }
.home-news-card h3 { font-size: 1.25rem; margin: 12px 0; line-height: 1.4; }
.home-news-card h3 a { text-decoration: none; color: var(--primary-color); transition: var(--transition); }
.home-news-card h3 a:hover { color: var(--accent-color); }
.home-news-card p { color: var(--text-muted); font-size: 0.95rem; margin-bottom: 20px; }

/* ================= 全局底部页脚 (Footer) ================= */
.site-footer { background-color: var(--primary-color); color: #D1D5DB; padding: 80px 5% 0 5%; }
.footer-container { display: grid; grid-template-columns: 2fr 1fr 1fr 1.5fr; gap: 40px; max-width: 1200px; margin: 0 auto; padding-bottom: 60px; border-bottom: 1px solid rgba(255, 255, 255, 0.1); }
.footer-logo { font-size: 1.8rem; font-weight: 800; color: var(--white); margin-bottom: 20px; letter-spacing: -0.5px; }
.footer-logo span { color: var(--accent-color); }
.company-desc { line-height: 1.6; font-size: 0.95rem; max-width: 300px; }
.footer-column h4 { color: var(--white); font-size: 1.1rem; margin-bottom: 24px; position: relative; padding-bottom: 10px; }
.footer-column h4::after { content: ''; position: absolute; left: 0; bottom: 0; width: 40px; height: 2px; background-color: var(--accent-color); }
.footer-links, .contact-info { list-style: none; }
.footer-links li, .contact-info li { margin-bottom: 12px; font-size: 0.95rem; }
.footer-links a, .contact-info a { color: #D1D5DB; text-decoration: none; transition: var(--transition); }
.footer-links a:hover, .contact-info a:hover { color: var(--white); padding-left: 5px; }
.contact-info strong { color: var(--white); display: inline-block; width: 80px; }
.footer-bottom { text-align: center; padding: 24px 0; font-size: 0.85rem; color: #9CA3AF; }

/* ================= 子页面：通用头部与面包屑 ================= */
.page-header { background-color: var(--primary-color); color: var(--white); padding: 80px 5%; text-align: center; }
.page-header h1 { font-size: 2.5rem; margin-bottom: 16px; }
.page-header p { color: #D1D5DB; font-size: 1.1rem; max-width: 600px; margin: 0 auto; }
.breadcrumb { padding: 20px 5%; background-color: #F9FAFB; font-size: 0.9rem; color: var(--text-muted); border-bottom: 1px solid #E5E7EB; }
.breadcrumb a { color: var(--primary-color); text-decoration: none; }
.breadcrumb a:hover { text-decoration: underline; }
.breadcrumb span { color: var(--text-main); font-weight: 600; }

/* ================= 子页面：产品列表页与详情页 ================= */
.category-section { padding: 80px 5%; }
.category-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(350px, 1fr)); gap: 30px; max-width: 1200px; margin: 0 auto; }
.category-card { position: relative; height: 300px; border-radius: var(--border-radius); overflow: hidden; text-decoration: none; display: block; }
.category-image { width: 100%; height: 100%; background-size: cover; background-position: center; transition: transform 0.6s ease; }
.category-card:hover .category-image { transform: scale(1.05); }
.category-overlay { position: absolute; inset: 0; background: linear-gradient(to top, rgba(10, 37, 64, 0.9) 0%, rgba(10, 37, 64, 0.2) 100%); display: flex; flex-direction: column; justify-content: flex-end; padding: 30px; }
.category-overlay h2 { color: var(--white); font-size: 1.8rem; margin-bottom: 8px; }
.category-overlay span { color: var(--accent-color); font-weight: 600; }

.product-detail-section { padding: 60px 5%; max-width: 1400px; margin: 0 auto; }
.product-layout { display: grid; grid-template-columns: 1fr 2fr; gap: 60px; }
.product-main-img { width: 100%; height: 400px; border-radius: var(--border-radius); background-size: cover; background-position: center; border: 1px solid #E5E7EB; margin-bottom: 24px; }
.download-box { background-color: #F9FAFB; padding: 24px; border-radius: var(--border-radius); border: 1px solid #E5E7EB; }
.download-box h3 { font-size: 1.1rem; margin-bottom: 16px; color: var(--primary-color); }
.product-specs h1 { font-size: 2.5rem; color: var(--primary-color); line-height: 1.2; margin-bottom: 8px; }
.cas-number { font-size: 1.1rem; color: var(--text-muted); margin-bottom: 32px; padding-bottom: 16px; border-bottom: 1px solid #E5E7EB; }
.cas-number strong { color: var(--accent-color); }
.spec-table-wrapper { overflow-x: auto; margin-bottom: 40px; }
.spec-table { width: 100%; border-collapse: collapse; text-align: left; font-size: 0.95rem; }
.spec-table th, .spec-table td { padding: 16px; border-bottom: 1px solid #E5E7EB; }
.spec-table th { background-color: var(--primary-color); color: var(--white); font-weight: 600; }
.spec-table tbody tr:hover { background-color: #F9FAFB; }
.spec-table td:first-child { font-weight: 600; color: var(--primary-color); width: 35%; }
.product-description h3 { font-size: 1.5rem; color: var(--primary-color); margin-bottom: 16px; }
.product-description p { color: var(--text-main); line-height: 1.8; margin-bottom: 24px; }

/* ================= 子页面：新闻列表与详情页 ================= */
.news-list-section { max-width: 1000px; margin: 80px auto; padding: 0 5%; }
.news-item { display: flex; gap: 40px; margin-bottom: 50px; padding-bottom: 50px; border-bottom: 1px solid #E5E7EB; }
.news-thumb { width: 300px; height: 200px; border-radius: var(--border-radius); background-size: cover; background-position: center; flex-shrink: 0; }
.news-summary { flex-grow: 1; }
.news-date { display: block; color: var(--accent-color); font-weight: 600; font-size: 0.9rem; margin-bottom: 10px; }
.news-summary h2 { margin-bottom: 16px; line-height: 1.3; }
.news-summary h2 a { text-decoration: none; color: var(--primary-color); transition: var(--transition); }
.news-summary h2 a:hover { color: var(--accent-color); }
.news-summary p { color: var(--text-muted); margin-bottom: 20px; }
.read-more { font-weight: 600; color: var(--primary-color); text-decoration: none; border-bottom: 2px solid var(--accent-color); padding-bottom: 2px; }

.pagination { display: flex; justify-content: center; gap: 10px; margin-top: 40px; }
.page-btn { padding: 8px 16px; border: 1px solid #E5E7EB; text-decoration: none; color: var(--text-main); border-radius: 4px; }
.page-btn.active, .page-btn:hover { background-color: var(--primary-color); color: var(--white); border-color: var(--primary-color); }

.news-detail-container { max-width: 800px; margin: 80px auto; padding: 0 5%; }
.article-header { margin-bottom: 40px; text-align: center; }
.article-date { color: var(--accent-color); font-weight: 600; }
.article-header h1 { font-size: 2.2rem; color: var(--primary-color); margin: 16px 0; line-height: 1.3; }
.article-meta { color: var(--text-muted); font-size: 0.9rem; }
.article-featured-image { margin-bottom: 40px; border-radius: var(--border-radius); overflow: hidden; }
.article-featured-image img { width: 100%; height: auto; display: block; }
.article-body { font-size: 1.1rem; color: #374151; line-height: 1.8; }
.article-body p { margin-bottom: 24px; }
.article-body h3 { color: var(--primary-color); margin: 40px 0 20px 0; }
.article-footer { margin-top: 60px; padding-top: 30px; border-top: 1px solid #E5E7EB; }

/* ================= 统一响应式断点 (Media Queries) ================= */
@media (max-width: 992px) {
    .hero { padding: 120px 5% 100px 5%; min-height: 60vh; }
    .hero h1 { font-size: 2.8rem; }
    .hero-carousel::after { background: linear-gradient(to top, rgba(10, 37, 64, 0.9) 0%, rgba(10, 37, 64, 0.4) 100%); }
    .carousel-indicators { left: 50%; transform: translateX(-50%); }
    .footer-container { grid-template-columns: 1fr 1fr; }
    .product-layout { grid-template-columns: 1fr; gap: 40px; }
}

@media (max-width: 768px) {
    .nav-links { display: none; }
    .hero h1 { font-size: 2.2rem; }
    .hero-actions { flex-direction: column; }
    .footer-container { grid-template-columns: 1fr; }
    .news-item { flex-direction: column; gap: 20px; }
    .news-thumb { width: 100%; height: 250px; }
}