:root {
    --primary: #003366;
    --accent: #FF6600;
    --bg-light: #F8FAFC;
    --text-main: #1E293B;
    --text-muted: #64748B;
    --white: #FFFFFF;
}

* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { font-family: "PingFang SC", "Microsoft YaHei", sans-serif; color: var(--text-main); line-height: 1.6; background: #fff; }

/* --- 首页统一头部 --- */
header {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    position: fixed; width: 100%; top: 0; z-index: 1000;
    box-shadow: 0 2px 15px rgba(0,0,0,0.08);
}
.nav-container {
    max-width: 1200px; margin: 0 auto;
    display: flex; justify-content: space-between; align-items: center; padding: 15px 20px;
}
.logo { font-size: 24px; font-weight: 800; color: var(--primary); text-decoration: none; display: flex; align-items: center; }
.logo span { color: var(--accent); }
.nav-menu { display: flex; list-style: none; }
.nav-menu li { margin-left: 25px; }
.nav-menu a { text-decoration: none; color: var(--text-main); font-weight: 500; font-size: 15px; transition: 0.3s; }
.nav-menu a:hover { color: var(--primary); }
/* 激活状态 */
.nav-menu a.active { color: var(--primary); font-weight: bold; }
.mobile-btn { display: none; font-size: 24px; cursor: pointer; color: var(--primary); }

/* --- 产品中心 Banner --- */
.page-banner {
    padding: 140px 20px 60px;
    background: linear-gradient(rgba(0,51,102,0.9), rgba(0,51,102,0.9)), url('https://images.unsplash.com/photo-1581092160607-ee22621dd758?auto=format&fit=crop&q=80') center/cover;
    color: #fff; text-align: center;
}
.page-banner h1 { font-size: 36px; margin-bottom: 10px; }
.breadcrumb { font-size: 14px; opacity: 0.8; }
.breadcrumb a { color: #fff; text-decoration: none; }

/* --- 产品筛选/分类 (SEO优化点) --- */
.filter-bar {
    max-width: 1200px; margin: 40px auto 20px; padding: 0 20px;
    display: flex; gap: 15px; flex-wrap: wrap;
}
.filter-item {
    padding: 8px 20px; background: var(--bg-light); border-radius: 20px;
    text-decoration: none; color: var(--text-muted); font-size: 14px; transition: 0.3s;
}
.filter-item:hover, .filter-item.active { background: var(--primary); color: #fff; }

/* --- 产品网格列表 --- */
.product-section { padding: 20px 20px 80px; max-width: 1200px; margin: 0 auto; }
.product-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 30px;
}
.product-card {
    background: #fff; border: 1px solid #eee; border-radius: 8px;
    overflow: hidden; transition: 0.3s; display: flex; flex-direction: column;
}
.product-card:hover { transform: translateY(-10px); box-shadow: 0 15px 35px rgba(0,0,0,0.1); }

.prod-img { height: 260px; background: #f4f4f4; position: relative; overflow: hidden; }
.prod-img img { width: 100%; height: 100%; object-fit: contain; padding: 20px; transition: 0.5s; }
.product-card:hover .prod-img img { transform: scale(1.05); }

.prod-info { padding: 20px; flex-grow: 1; display: flex; flex-direction: column; }
.prod-info h3 { font-size: 18px; color: var(--primary); margin-bottom: 10px; }
.prod-info h3 a {font-size: 18px; color: var(--primary); text-decoration:none;}
/* 产品参数标签 */
.prod-tags { display: flex; flex-wrap: wrap; gap: 8px; margin-bottom: 15px; }
.tag { background: #F1F5F9; color: #475569; font-size: 12px; padding: 2px 8px; border-radius: 4px; }

.prod-desc { font-size: 14px; color: var(--text-muted); margin-bottom: 20px; line-height: 1.5; flex-grow: 1; }

.btn-detail {
    display: block; width: 100%; padding: 10px; text-align: center;
    background: #fff; border: 1px solid var(--primary); color: var(--primary);
    text-decoration: none; border-radius: 4px; font-weight: bold; transition: 0.3s;
}
.btn-detail:hover { background: var(--primary); color: #fff; }

/* --- 首页统一页脚 --- */
footer { background: #0f172a; color: #94a3b8; padding: 80px 20px 30px; margin-top: 60px; }
.footer-grid { max-width: 1200px; margin: 0 auto; display: grid; grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); gap: 40px; }
.footer-grid h4 { color: #fff; margin-bottom: 25px; }
.footer-bottom { text-align: center; margin-top: 60px; padding-top: 20px; border-top: 1px solid #334155; font-size: 13px; }

/* 移动端适配 */
@media (max-width: 768px) {
    .nav-menu { display: none; position: absolute; top: 65px; left: 0; width: 100%; background: #fff; flex-direction: column; padding: 20px; box-shadow: 0 10px 15px rgba(0,0,0,0.1); }
    .nav-menu.active { display: flex; }
    .nav-menu li { margin: 15px 0; }
    .mobile-btn { display: block; }
    .product-grid { grid-template-columns: 1fr; }
    .page-banner h1 { font-size: 28px; }
}