:root {
    --primary: #f0c040;
    --primary-dark: #e67e22;
    --bg: #ffffff;
    --bg-light: #f8f9fa;
    --text: #1a1a2e;
    --text-light: #555;
    --card-bg: #ffffff;
    --shadow: 0 4px 20px rgba(0,0,0,0.08);
    --radius: 16px;
    --transition: 0.3s ease;
}
[data-theme="dark"] {
    --bg: #1a1a2e;
    --bg-light: #16213e;
    --text: #e0e0e0;
    --text-light: #aaa;
    --card-bg: #0f3460;
    --shadow: 0 4px 20px rgba(0,0,0,0.4);
}
* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background: var(--bg);
    color: var(--text);
    line-height: 1.6;
    transition: background var(--transition), color var(--transition);
}
.container { max-width: 1200px; margin: 0 auto; padding: 0 20px; }
/* 头部 */
#header {
    position: fixed; top: 0; left: 0; width: 100%; z-index: 1000;
    background: var(--bg); box-shadow: 0 2px 10px rgba(0,0,0,0.05);
    transition: background var(--transition);
    backdrop-filter: blur(10px);
    background: rgba(255,255,255,0.9);
}
[data-theme="dark"] #header { background: rgba(26,26,46,0.9); }
.header-inner { display: flex; align-items: center; justify-content: space-between; padding: 10px 0; }
.main-nav ul { display: flex; list-style: none; gap: 25px; }
.main-nav a { text-decoration: none; color: var(--text); font-weight: 500; transition: color var(--transition); position: relative; }
.main-nav a:hover, .main-nav a.active { color: var(--primary); }
.main-nav a::after { content: ''; position: absolute; bottom: -4px; left: 0; width: 0; height: 2px; background: var(--primary); transition: width var(--transition); }
.main-nav a:hover::after, .main-nav a.active::after { width: 100%; }
.header-actions { display: flex; gap: 15px; align-items: center; }
.header-actions button { background: none; border: none; cursor: pointer; color: var(--text); padding: 5px; border-radius: 8px; transition: background var(--transition); }
.header-actions button:hover { background: var(--bg-light); }
#menuToggle { display: none; }
/* 面包屑 */
.breadcrumb { background: var(--bg-light); padding: 10px 0; margin-top: 70px; }
.breadcrumb ol { list-style: none; display: flex; gap: 10px; font-size: 14px; }
.breadcrumb a { color: var(--primary); text-decoration: none; }
.breadcrumb li+li::before { content: "›"; margin-right: 10px; color: var(--text-light); }
/* Hero */
.hero {
    padding: 80px 0;
    background: linear-gradient(135deg, var(--primary), var(--primary-dark));
    color: #fff;
}
.hero-content { display: flex; align-items: center; gap: 40px; }
.hero-text { flex: 1; }
.hero-text h1 { font-size: 2.2rem; margin-bottom: 20px; line-height: 1.3; }
.hero-text p { font-size: 1.1rem; margin-bottom: 30px; opacity: 0.9; }
.hero-buttons { display: flex; gap: 15px; }
.btn { padding: 12px 30px; border-radius: 50px; text-decoration: none; font-weight: 600; transition: transform var(--transition), box-shadow var(--transition); display: inline-block; }
.btn:hover { transform: translateY(-3px); box-shadow: 0 8px 25px rgba(0,0,0,0.2); }
.btn-primary { background: #fff; color: var(--primary-dark); }
.btn-secondary { background: transparent; border: 2px solid #fff; color: #fff; }
.hero-image { flex: 1; text-align: center; }
.hero-image svg { max-width: 100%; height: auto; }
/* 通用section */
.section { padding: 60px 0; }
.bg-light { background: var(--bg-light); }
.bg-gradient { background: linear-gradient(135deg, var(--primary), var(--primary-dark)); color: #fff; }
h2 { font-size: 2rem; margin-bottom: 30px; text-align: center; position: relative; }
h2::after { content: ''; display: block; width: 60px; height: 4px; background: var(--primary); margin: 10px auto 0; border-radius: 2px; }
.card {
    background: var(--card-bg);
    border-radius: var(--radius);
    padding: 30px;
    box-shadow: var(--shadow);
    transition: transform var(--transition), box-shadow var(--transition);
    text-align: center;
    backdrop-filter: blur(10px);
    background: rgba(255,255,255,0.85);
}
[data-theme="dark"] .card {
    background: rgba(15,52,96,0.85);
}
.card:hover { transform: translateY(-5px); box-shadow: 0 8px 30px rgba(0,0,0,0.12); }
.brand-grid, .team-grid, .products-grid, .services-grid, .core-grid, .cases-grid, .testimonial-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); gap: 30px; margin-top: 20px; }
.team-member h3 { margin: 15px 0 5px; }
.products-grid .card svg { margin-bottom: 15px; }
.core-grid .card { display: flex; flex-direction: column; align-items: center; gap: 10px; }
/* 新闻 */
.news-grid, .articles-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); gap: 25px; }
.article-card { background: var(--card-bg); border-radius: var(--radius); padding: 20px; box-shadow: var(--shadow); backdrop-filter: blur(10px); background: rgba(255,255,255,0.85); }
[data-theme="dark"] .article-card { background: rgba(15,52,96,0.85); }
.article-card h3 { margin-bottom: 10px; }
.article-card .meta { font-size: 0.85rem; color: var(--text-light); margin-bottom: 10px; }
.article-card p { margin-bottom: 15px; }
.read-more { color: var(--primary); text-decoration: none; font-weight: 600; }
/* FAQ */
.faq-list { max-width: 800px; margin: 0 auto; }
.faq-item { background: var(--card-bg); border-radius: var(--radius); margin-bottom: 15px; overflow: hidden; box-shadow: var(--shadow); backdrop-filter: blur(10px); background: rgba(255,255,255,0.85); }
[data-theme="dark"] .faq-item { background: rgba(15,52,96,0.85); }
.faq-question { padding: 20px; cursor: pointer; display: flex; justify-content: space-between; align-items: center; font-weight: 600; transition: background var(--transition); }
.faq-question:hover { background: var(--bg-light); }
.faq-answer { max-height: 0; overflow: hidden; transition: max-height 0.4s ease, padding 0.4s ease; padding: 0 20px; }
.faq-answer.open { max-height: 300px; padding: 0 20px 20px; }
.faq-toggle { font-size: 1.2rem; transition: transform var(--transition); }
.faq-item.open .faq-toggle { transform: rotate(45deg); }
/* HowTo */
.howto-content { max-width: 800px; margin: 0 auto; }
.howto-content h3 { margin-top: 25px; color: var(--primary); }
.howto-content ol { padding-left: 20px; }
/* 联系 */
.contact-info p { margin-bottom: 10px; }
.qr-codes { display: flex; gap: 30px; justify-content: center; margin-top: 30px; }
.qr { text-align: center; }
.qr svg { border-radius: 10px; }
/* 底部 */
#footer { background: #1a1a2e; color: #ccc; padding: 40px 0; position: relative; }
.footer-inner { display: flex; justify-content: space-between; gap: 40px; flex-wrap: wrap; }
.footer-info p { margin-bottom: 8px; font-size: 0.9rem; }
.footer-qr { text-align: center; }
.footer-qr svg { border-radius: 8px; }
#backToTop {
    position: fixed; bottom: 30px; right: 30px;
    width: 50px; height: 50px; border-radius: 50%;
    background: var(--primary); color: #fff; border: none;
    font-size: 1.5rem; cursor: pointer;
    box-shadow: 0 4px 15px rgba(0,0,0,0.2);
    transition: transform var(--transition), opacity var(--transition);
    opacity: 0; visibility: hidden;
}
#backToTop.visible { opacity: 1; visibility: visible; }
#backToTop:hover { transform: scale(1.1); }
/* 搜索 */
.search-overlay {
    position: fixed; top: 0; left: 0; width: 100%; height: 100%;
    background: rgba(0,0,0,0.5); display: none; align-items: center; justify-content: center;
    z-index: 2000;
    backdrop-filter: blur(5px);
}
.search-overlay.active { display: flex; }
.search-box { background: var(--card-bg); padding: 20px; border-radius: var(--radius); width: 90%; max-width: 500px; display: flex; gap: 10px; backdrop-filter: blur(10px); background: rgba(255,255,255,0.9); }
[data-theme="dark"] .search-box { background: rgba(15,52,96,0.9); }
.search-box input { flex: 1; padding: 12px; border: 1px solid #ddd; border-radius: 8px; font-size: 1rem; background: var(--bg); color: var(--text); }
.search-box button { background: var(--primary); border: none; color: #fff; padding: 12px 20px; border-radius: 8px; cursor: pointer; }
/* 响应式 */
@media (max-width: 768px) {
    .main-nav { display: none; position: absolute; top: 100%; left: 0; width: 100%; background: var(--bg); padding: 20px; box-shadow: 0 10px 20px rgba(0,0,0,0.1); backdrop-filter: blur(10px); background: rgba(255,255,255,0.9); }
    [data-theme="dark"] .main-nav { background: rgba(26,26,46,0.9); }
    .main-nav.open { display: block; }
    .main-nav ul { flex-direction: column; gap: 15px; }
    #menuToggle { display: block; }
    .hero-content { flex-direction: column; text-align: center; }
    .hero-text h1 { font-size: 1.8rem; }
    .hero-buttons { justify-content: center; }
    .footer-inner { flex-direction: column; text-align: center; }
}
@media (max-width: 480px) {
    .hero-text h1 { font-size: 1.4rem; }
    .section { padding: 40px 0; }
}
/* 动画 */
.fade-in { opacity: 0; transform: translateY(20px); transition: opacity 0.6s ease, transform 0.6s ease; }
.fade-in.visible { opacity: 1; transform: translateY(0); }
/* 友情链接 */
.friend-links { display: flex; flex-wrap: wrap; gap: 15px; justify-content: center; }
.friend-links a { color: var(--primary); text-decoration: none; }
/* 网站地图 */
.sitemap-list { display: flex; flex-wrap: wrap; gap: 15px; justify-content: center; list-style: none; }
.sitemap-list a { color: var(--text); text-decoration: none; }
/* 滚动导航高亮 */
.nav-highlight { color: var(--primary) !important; }