/* 全局重置与基础样式 */
* { margin: 0; padding: 0; box-sizing: border-box; }
body { font-family: 'Segoe UI', 'Microsoft YaHei', sans-serif; line-height: 1.6; color: #222; background: #f9fafb; scroll-behavior: smooth; }
a { color: #1a3a5c; text-decoration: none; }
a:hover { text-decoration: underline; }
img { max-width: 100%; height: auto; display: block; }
ul, ol { padding-left: 1.5rem; }

/* 导航吸顶 */
.navbar { position: sticky; top: 0; z-index: 1000; background: #ffffff; border-bottom: 1px solid #e0e0e0; padding: 0.8rem 2rem; display: flex; align-items: center; justify-content: space-between; box-shadow: 0 2px 4px rgba(0,0,0,0.05); }
.navbar .logo a { font-size: 1.5rem; font-weight: 700; color: #1a3a5c; }
.navbar .nav-links { display: flex; gap: 1.5rem; list-style: none; padding-left: 0; }
.navbar .nav-links li a { font-weight: 500; padding: 0.3rem 0; border-bottom: 2px solid transparent; transition: 0.2s; }
.navbar .nav-links li a:hover { border-bottom-color: #1a3a5c; }
.menu-toggle { display: none; font-size: 1.8rem; cursor: pointer; background: none; border: none; }
/* 移动菜单 */
@media (max-width: 768px) {
    .navbar .nav-links { display: none; flex-direction: column; background: #fff; position: absolute; top: 60px; left: 0; width: 100%; padding: 1rem 2rem; border-bottom: 1px solid #ddd; }
    .navbar .nav-links.active { display: flex; }
    .menu-toggle { display: block; }
}

/* 容器 */
.container { max-width: 1200px; margin: 0 auto; padding: 0 1.5rem; }

/* 面包屑 */
.breadcrumb { padding: 1rem 0; font-size: 0.9rem; color: #666; }
.breadcrumb a { color: #1a3a5c; }
.breadcrumb span { margin: 0 0.3rem; }

/* 通用标题 */
h1 { font-size: 2.2rem; margin: 1.5rem 0 1rem; color: #1a3a5c; }
h2 { font-size: 1.8rem; margin: 2rem 0 1rem; color: #1f4a7a; border-left: 4px solid #1a3a5c; padding-left: 0.8rem; }
h3 { font-size: 1.4rem; margin: 1.5rem 0 0.8rem; color: #2c3e50; }
h4 { font-size: 1.2rem; margin: 1rem 0 0.5rem; color: #34495e; }

/* 首屏区 - 渐变Banner */
.hero { background: linear-gradient(135deg, #1a3a5c 0%, #2a5a8c 100%); color: #fff; padding: 3rem 1.5rem; text-align: center; border-radius: 0 0 20px 20px; margin-bottom: 2rem; }
.hero h1 { color: #fff; font-size: 2.5rem; margin: 0 0 1rem; }
.hero p { font-size: 1.2rem; max-width: 800px; margin: 0 auto 1.5rem; }
.hero .brand-tag { background: rgba(255,255,255,0.2); display: inline-block; padding: 0.3rem 1.5rem; border-radius: 30px; font-weight: 600; }

/* 轮播 */
.carousel { position: relative; overflow: hidden; margin: 2rem 0; border-radius: 12px; }
.carousel-slide { display: flex; transition: transform 0.5s ease; }
.carousel-item { min-width: 100%; padding: 2rem; background: #eef2f7; text-align: center; }
.carousel-item svg { width: 80px; height: 80px; margin: 0 auto 1rem; }
.carousel-controls { display: flex; justify-content: center; gap: 1rem; margin-top: 1rem; }
.carousel-btn { background: #1a3a5c; color: #fff; border: none; padding: 0.5rem 1.2rem; border-radius: 30px; cursor: pointer; transition: background 0.3s; }
.carousel-btn:hover { background: #2a5a8c; }

/* 网格 */
.grid-2 { display: grid; grid-template-columns: 1fr 1fr; gap: 2rem; margin: 2rem 0; }
.grid-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 2rem; margin: 2rem 0; }
@media (max-width: 768px) {
    .grid-2, .grid-3 { grid-template-columns: 1fr; }
}

/* 圆角卡片 + 毛玻璃效果 + hover动画 */
.card { background: rgba(255, 255, 255, 0.7); backdrop-filter: blur(10px); -webkit-backdrop-filter: blur(10px); padding: 1.5rem; border-radius: 12px; box-shadow: 0 2px 8px rgba(0,0,0,0.05); transition: transform 0.3s, box-shadow 0.3s; }
.card:hover { transform: translateY(-4px); box-shadow: 0 4px 16px rgba(0,0,0,0.1); }
.card h3 { margin-top: 0; }

/* 数字动画 */
.stats { display: flex; justify-content: space-around; flex-wrap: wrap; gap: 1rem; margin: 2rem 0; background: #1a3a5c; color: #fff; padding: 2rem; border-radius: 12px; }
.stat-item { text-align: center; }
.stat-number { font-size: 2.5rem; font-weight: 700; }
.stat-label { font-size: 1rem; opacity: 0.9; }

/* FAQ */
.faq-item { border-bottom: 1px solid #ddd; padding: 1rem 0; }
.faq-question { cursor: pointer; font-weight: 600; display: flex; justify-content: space-between; align-items: center; }
.faq-answer { max-height: 0; overflow: hidden; transition: max-height 0.4s ease; padding-top: 0.5rem; color: #444; }
.faq-item.active .faq-answer { max-height: 500px; }

/* 文章卡片 */
.article-card { border-bottom: 1px solid #eee; padding: 1rem 0; }
.article-card h4 { margin-bottom: 0.3rem; }
.article-meta { font-size: 0.85rem; color: #888; }

/* 返回顶部 */
.back-to-top { position: fixed; bottom: 2rem; right: 2rem; background: #1a3a5c; color: #fff; width: 48px; height: 48px; border-radius: 50%; display: flex; align-items: center; justify-content: center; cursor: pointer; opacity: 0; transition: opacity 0.3s, transform 0.3s; border: none; font-size: 1.5rem; }
.back-to-top.visible { opacity: 0.9; }
.back-to-top:hover { transform: scale(1.1); }

/* 暗黑模式 */
.dark-mode { background: #1e1e1e; color: #ddd; }
.dark-mode .navbar { background: #2a2a2a; border-bottom-color: #444; }
.dark-mode .card { background: rgba(42, 42, 42, 0.8); backdrop-filter: blur(10px); -webkit-backdrop-filter: blur(10px); color: #ddd; }
.dark-mode .hero { background: linear-gradient(135deg, #0f1f2f 0%, #1a3a5c 100%); }
.dark-mode .stats { background: #0f1f2f; }
.dark-mode .carousel-item { background: #2a2a2a; }
.dark-mode a { color: #8ab4f8; }
.dark-mode .breadcrumb { color: #aaa; }
.dark-mode .faq-question { color: #ddd; }

/* 搜索 */
.search-box { display: flex; align-items: center; gap: 0.5rem; }
.search-box input { padding: 0.4rem 0.8rem; border: 1px solid #ccc; border-radius: 20px; }
.search-box button { background: #1a3a5c; color: #fff; border: none; padding: 0.4rem 1rem; border-radius: 20px; cursor: pointer; transition: background 0.3s; }
.search-box button:hover { background: #2a5a8c; }

/* 页脚 */
footer { background: #1a3a5c; color: #cfd8dc; padding: 2rem 1.5rem; margin-top: 3rem; border-radius: 20px 20px 0 0; }
footer a { color: #b0bec5; }
footer .footer-links { display: flex; flex-wrap: wrap; gap: 1.5rem; justify-content: center; margin-bottom: 1rem; }
footer .footer-links a { font-size: 0.9rem; }
footer .copyright { text-align: center; font-size: 0.85rem; border-top: 1px solid #2a4a6c; padding-top: 1rem; }

/* 滚动动画 */
.fade-in { opacity: 0; transform: translateY(20px); transition: opacity 0.6s, transform 0.6s; }
.fade-in.visible { opacity: 1; transform: translateY(0); }

/* 其他 */
.section { margin: 2.5rem 0; }
.contact-info p { margin: 0.3rem 0; }
.tag { background: #e0e7ef; padding: 0.2rem 0.8rem; border-radius: 20px; font-size: 0.8rem; }