:root {
    --primary: #0a4d8c;
    --primary-light: #1565c0;
    --primary-dark: #063463;
    --accent: #00b4d8;
    --accent-light: #48cae4;
    --dark: #0d1b2a;
    --dark-2: #1b263b;
    --gray-50: #f8fafc;
    --gray-100: #f1f5f9;
    --gray-200: #e2e8f0;
    --gray-300: #cbd5e1;
    --gray-400: #94a3b8;
    --gray-500: #64748b;
    --gray-600: #475569;
    --gray-700: #334155;
    --gray-800: #1e293b;
    --white: #ffffff;
    --gradient-primary: linear-gradient(135deg, #0a4d8c 0%, #00b4d8 100%);
    --gradient-dark: linear-gradient(135deg, #0d1b2a 0%, #1b263b 50%, #0a4d8c 100%);
    --gradient-hero: linear-gradient(135deg, rgba(10,77,140,0.92) 0%, rgba(0,180,216,0.7) 100%);
    --shadow-sm: 0 1px 3px rgba(0,0,0,0.08);
    --shadow-md: 0 4px 20px rgba(0,0,0,0.1);
    --shadow-lg: 0 10px 40px rgba(0,0,0,0.15);
    --shadow-xl: 0 20px 60px rgba(0,0,0,0.2);
    --radius-sm: 6px;
    --radius-md: 10px;
    --radius-lg: 16px;
    --radius-xl: 24px;
    --transition: all 0.35s cubic-bezier(0.4, 0, 0.2, 1);
    --max-width: 1280px;
}
* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; font-size: 16px; }
body { font-family: "Microsoft YaHei", "PingFang SC", "Helvetica Neue", Arial, sans-serif; line-height: 1.7; color: var(--gray-700); background: var(--white); overflow-x: hidden; }
img { max-width: 100%; display: block; }
a { text-decoration: none; color: inherit; transition: var(--transition); }
ul { list-style: none; }
.container { max-width: var(--max-width); margin: 0 auto; padding: 0 24px; }

/* 导航栏 */
.header { position: sticky; top: 0; z-index: 1000; background: rgba(255,255,255,0.98); backdrop-filter: blur(12px); box-shadow: var(--shadow-sm); transition: var(--transition); }
.header.scrolled { box-shadow: var(--shadow-md); }
.nav { display: flex; justify-content: space-between; align-items: center; height: 72px; }
.logo { display: flex; align-items: center; gap: 10px; font-size: 22px; font-weight: 700; color: var(--dark); flex-shrink: 0; }
.nav-menu { display: flex; align-items: center; gap: 0; }
.nav-item { position: relative; }
.nav-link { display: flex; align-items: center; gap: 4px; padding: 0 24px; height: 72px; font-size: 16px; font-weight: 600; color: var(--gray-700); position: relative; cursor: pointer; }
.nav-link::after { content: ''; position: absolute; bottom: 0; left: 50%; width: 0; height: 3px; background: var(--gradient-primary); transition: var(--transition); transform: translateX(-50%); }
.nav-link:hover { color: var(--primary); }
.nav-link:hover::after { width: 60%; }
.nav-arrow { font-size: 10px; transition: var(--transition); }
.nav-item:hover .nav-arrow { transform: rotate(180deg); }
.dropdown { position: absolute; top: 72px; left: 50%; transform: translateX(-50%) translateY(10px); background: var(--white); min-width: 220px; border-radius: var(--radius-md); box-shadow: var(--shadow-lg); opacity: 0; visibility: hidden; transition: var(--transition); padding: 8px 0; }
.nav-item:hover .dropdown { opacity: 1; visibility: visible; transform: translateX(-50%) translateY(0); }
.dropdown::before { content: ''; position: absolute; top: -8px; left: 50%; transform: translateX(-50%) rotate(45deg); width: 16px; height: 16px; background: var(--white); }
.dropdown-item { display: block; padding: 12px 24px; font-size: 14px; color: var(--gray-600); transition: var(--transition); border-left: 3px solid transparent; }
.dropdown-item:hover { background: var(--gray-50); color: var(--primary); border-left-color: var(--accent); padding-left: 28px; }
.nav-cta { margin-left: 16px; }
.nav-cta .btn { padding: 10px 28px; font-size: 14px; }
.mobile-toggle { display: none; background: none; border: none; cursor: pointer; padding: 8px; }
.mobile-toggle span { display: block; width: 24px; height: 2px; background: var(--dark); margin: 5px 0; transition: var(--transition); }

/* 按钮 */
.btn { display: inline-flex; align-items: center; justify-content: center; gap: 8px; padding: 14px 36px; font-size: 15px; font-weight: 600; border-radius: var(--radius-md); cursor: pointer; transition: var(--transition); border: none; letter-spacing: 0.5px; }
.btn-primary { background: var(--gradient-primary); color: var(--white); box-shadow: 0 4px 20px rgba(10,77,140,0.35); }
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 8px 30px rgba(10,77,140,0.45); }
.btn-outline { background: transparent; color: var(--primary); border: 2px solid var(--primary); }
.btn-outline:hover { background: var(--primary); color: var(--white); transform: translateY(-2px); }

/* 页面Banner */
.page-banner { background: var(--gradient-dark); color: var(--white); padding: 80px 0 60px; position: relative; overflow: hidden; }
.page-banner::after { content: ''; position: absolute; right: -100px; top: -100px; width: 400px; height: 400px; border-radius: 50%; background: rgba(0,180,216,0.06); }
.page-banner h1 { font-size: 42px; font-weight: 700; margin-bottom: 16px; position: relative; z-index: 2; }
.page-banner p { font-size: 17px; color: rgba(255,255,255,0.7); max-width: 85%; position: relative; z-index: 2; }
.breadcrumb { display: flex; gap: 8px; align-items: center; font-size: 14px; color: rgba(255,255,255,0.5); margin-bottom: 24px; position: relative; z-index: 2; }
.breadcrumb a { color: rgba(255,255,255,0.5); }
.breadcrumb a:hover { color: var(--accent); }

/* Section */
.section { padding: 80px 0; position: relative; }
.section-header { text-align: center; margin-bottom: 64px; }
.section-tag { display: inline-block; font-size: 14px; font-weight: 600; letter-spacing: 2px; color: var(--accent); text-transform: uppercase; margin-bottom: 16px; position: relative; padding: 0 40px; }
.section-tag::before, .section-tag::after { content: ''; position: absolute; top: 50%; width: 30px; height: 1px; background: var(--accent); }
.section-tag::before { left: 0; }
.section-tag::after { right: 0; }
.section-title { font-size: 38px; font-weight: 700; color: var(--dark); margin-bottom: 20px; line-height: 1.3; }
.section-subtitle { font-size: 17px; color: var(--gray-500); max-width: 720px; margin: 0 auto; line-height: 1.8; }

/* 产品展示卡片 */
.product-showcase { display: grid; grid-template-columns: 1fr; gap: 48px; }
.product-block { background: var(--white); border-radius: var(--radius-xl); overflow: hidden; box-shadow: var(--shadow-md); border: 1px solid var(--gray-100); transition: var(--transition); }
.product-block:hover { box-shadow: var(--shadow-xl); }
.product-block-inner { display: grid; grid-template-columns: 1fr 1fr; gap: 0; align-items: stretch; }
.product-block-img { position: relative; overflow: hidden; background: var(--gray-50); min-height: 400px; }
.product-block-img img { width: 100%; height: 100%; object-fit: cover; transition: transform 0.6s ease; }
.product-block:hover .product-block-img img { transform: scale(1.05); }
.product-block-badge { position: absolute; top: 20px; left: 20px; background: var(--gradient-primary); color: var(--white); font-size: 13px; font-weight: 600; padding: 6px 16px; border-radius: 20px; box-shadow: var(--shadow-md); }
.product-block-content { padding: 48px; display: flex; flex-direction: column; justify-content: center; }
.product-block-category { font-size: 14px; color: var(--accent); font-weight: 600; letter-spacing: 1px; text-transform: uppercase; margin-bottom: 12px; }
.product-block-title { font-size: 28px; font-weight: 700; color: var(--dark); margin-bottom: 16px; line-height: 1.3; }
.product-block-desc { font-size: 15px; color: var(--gray-500); line-height: 1.8; margin-bottom: 28px; }
.product-block-features { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; margin-bottom: 32px; }
.feature-item { display: flex; align-items: center; gap: 10px; font-size: 14px; color: var(--gray-600); }
.feature-item .check { width: 20px; height: 20px; border-radius: 50%; background: rgba(10,77,140,0.1); color: var(--primary); display: flex; align-items: center; justify-content: center; font-size: 12px; flex-shrink: 0; }
.product-block-actions { display: flex; gap: 12px; }

/* 产品规格预览 */
.product-specs-preview { display: grid; grid-template-columns: repeat(4, 1fr); gap: 16px; margin-bottom: 32px; }
.spec-card { background: var(--gray-50); border-radius: var(--radius-md); padding: 20px; text-align: center; border: 1px solid var(--gray-100); transition: var(--transition); }
.spec-card:hover { background: var(--white); box-shadow: var(--shadow-sm); border-color: var(--accent); }
.spec-card .spec-value { font-size: 22px; font-weight: 700; color: var(--primary); margin-bottom: 4px; }
.spec-card .spec-label { font-size: 12px; color: var(--gray-500); }

/* CTA */
.cta-section { background: var(--gradient-dark); color: var(--white); padding: 64px 0; text-align: center; position: relative; overflow: hidden; }
.cta-section::before { content: ''; position: absolute; top: -200px; right: -200px; width: 500px; height: 500px; background: radial-gradient(circle, rgba(0,180,216,0.12) 0%, transparent 70%); border-radius: 50%; }
.cta-section h2 { font-size: 32px; font-weight: 700; margin-bottom: 16px; position: relative; z-index: 2; }
.cta-section p { font-size: 16px; color: rgba(255,255,255,0.6); margin-bottom: 32px; position: relative; z-index: 2; }
.cta-section .btn { position: relative; z-index: 2; }
.cta-section .btn-primary { background: var(--accent); color: var(--dark); }
.cta-section .btn-primary:hover { background: var(--accent-light); }
.cta-section .btn-outline { color: var(--white); border-color: rgba(255,255,255,0.4); }
.cta-section .btn-outline:hover { background: rgba(255,255,255,0.1); border-color: var(--white); }

/* 页脚 */
.footer { background: var(--dark); color: var(--gray-400); padding: 80px 0 0; }
.footer-grid { display: grid; grid-template-columns: 1.5fr 1fr 1fr 1fr; gap: 48px; margin-bottom: 64px; }
.footer-brand .logo { color: var(--white); margin-bottom: 20px; }
.footer-brand p { font-size: 14px; color: var(--gray-400); line-height: 1.8; margin-bottom: 24px; }
.footer-contact { display: flex; flex-direction: column; gap: 12px; }
.footer-contact-item { display: flex; align-items: center; gap: 10px; font-size: 14px; color: var(--gray-400); }
.footer-contact-item svg { width: 16px; height: 16px; color: var(--accent); flex-shrink: 0; }
.footer-col h4 { font-size: 16px; font-weight: 700; color: var(--white); margin-bottom: 20px; }
.footer-col ul li { margin-bottom: 12px; }
.footer-col ul li a { font-size: 14px; color: var(--gray-400); transition: var(--transition); }
.footer-col ul li a:hover { color: var(--accent); padding-left: 6px; }
.footer-bottom { border-top: 1px solid rgba(255,255,255,0.08); padding: 24px 0; display: flex; justify-content: space-between; align-items: center; font-size: 13px; }
.footer-bottom a { color: var(--gray-400); }
.footer-bottom a:hover { color: var(--accent); }

/* 返回顶部 */
.back-to-top { position: fixed; bottom: 30px; right: 30px; width: 48px; height: 48px; background: var(--gradient-primary); color: var(--white); border-radius: 50%; display: flex; align-items: center; justify-content: center; cursor: pointer; opacity: 0; visibility: hidden; transition: var(--transition); z-index: 999; box-shadow: var(--shadow-md); border: none; }
.back-to-top.visible { opacity: 1; visibility: visible; }
.back-to-top:hover { transform: translateY(-4px); box-shadow: var(--shadow-lg); }
.back-to-top svg { width: 22px; height: 22px; }

/* 动画 */
.fade-up { opacity: 0; transform: translateY(40px); transition: opacity 0.8s ease, transform 0.8s ease; }
.fade-up.visible { opacity: 1; transform: translateY(0); }
.fade-up:nth-child(2) { transition-delay: 0.1s; }
.fade-up:nth-child(3) { transition-delay: 0.2s; }

/* 响应式 */
@media (max-width: 1024px) {
    .product-block-inner { grid-template-columns: 1fr; }
    .product-block-img { min-height: 300px; }
    .product-block-features { grid-template-columns: 1fr; }
    .product-specs-preview { grid-template-columns: repeat(2, 1fr); }
    .footer-grid { grid-template-columns: 1fr 1fr; gap: 32px; }
}
@media (max-width: 768px) {
    .nav-menu { display: none; }
    .mobile-toggle { display: block; }
    .nav-cta { display: none; }
    .section { padding: 64px 0; }
    .section-title { font-size: 28px; }
    .page-banner { padding: 60px 0 40px; }
    .page-banner h1 { font-size: 30px; }
    .product-block-content { padding: 32px 24px; }
    .product-block-title { font-size: 22px; }
    .product-specs-preview { grid-template-columns: 1fr 1fr; }
    .footer-grid { grid-template-columns: 1fr; }
    .footer-bottom { flex-direction: column; gap: 12px; text-align: center; }
}

/* === 顶部信息条 === */
.top-bar { background: var(--dark); color: var(--gray-300); font-size: 13px; padding: 8px 0; }
.top-bar .container { display: flex; justify-content: space-between; align-items: center; }
.top-bar-info { display: flex; gap: 28px; }
.top-bar-info span { display: flex; align-items: center; gap: 6px; }
.top-bar-info svg { width: 14px; height: 14px; color: var(--accent); }
.top-bar-right { display: flex; gap: 20px; }
.top-bar-right a:hover { color: var(--accent); }