/* 全局重置与基础样式 */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; font-size: 16px; }
body { font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans SC", sans-serif; line-height: 1.6; color: #1a1a2e; background: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%); transition: background 0.3s, color 0.3s; }
a { color: #1a3a5c; text-decoration: none; }
a:hover { text-decoration: underline; }
img, svg { max-width: 100%; height: auto; display: block; }
ul, ol { list-style: none; }
.container { max-width: 1200px; margin: 0 auto; padding: 0 20px; }

/* 暗黑模式变量 */
[data-theme="dark"] { background: #121212; color: #e0e0e0; }
[data-theme="dark"] a { color: #80b5ff; }
[data-theme="dark"] .header, [data-theme="dark"] .footer, [data-theme="dark"] .section, [data-theme="dark"] .card, [data-theme="dark"] .article-card, [data-theme="dark"] .faq-item, [data-theme="dark"] .step { background: #1e1e1e; color: #e0e0e0; }
[data-theme="dark"] .breadcrumb { color: #aaa; }
[data-theme="dark"] .btn { background: #3a5a8c; color: #fff; }

/* 导航吸顶 - 毛玻璃效果 */
.header { position: sticky; top: 0; z-index: 1000; background: rgba(255, 255, 255, 0.85); backdrop-filter: blur(12px); -webkit-backdrop-filter: blur(12px); box-shadow: 0 2px 8px rgba(0,0,0,0.08); transition: background 0.3s; }
.header .container { display: flex; align-items: center; justify-content: space-between; flex-wrap: wrap; padding: 10px 20px; }
.logo { display: flex; align-items: center; gap: 10px; }
.logo svg { width: 40px; height: 40px; }
.logo span { font-size: 1.2rem; font-weight: 700; color: #1a3a5c; }
.nav { display: flex; gap: 20px; align-items: center; }
.nav a { padding: 8px 0; font-size: 0.95rem; color: #333; border-bottom: 2px solid transparent; transition: 0.2s; }
.nav a:hover, .nav a.active { border-bottom-color: #1a3a5c; color: #1a3a5c; }
.menu-toggle { display: none; background: none; border: none; font-size: 1.5rem; cursor: pointer; padding: 4px; }
.search-box { display: flex; align-items: center; gap: 6px; }
.search-box input { padding: 6px 12px; border: 1px solid #ccc; border-radius: 20px; font-size: 0.9rem; outline: none; width: 160px; }
.search-box button { background: #1a3a5c; color: #fff; border: none; padding: 6px 14px; border-radius: 20px; cursor: pointer; font-size: 0.85rem; }
.dark-toggle { background: none; border: none; font-size: 1.2rem; cursor: pointer; padding: 4px; }

/* 面包屑 */
.breadcrumb { padding: 12px 0; font-size: 0.85rem; color: #666; background: rgba(241, 243, 245, 0.8); backdrop-filter: blur(8px); -webkit-backdrop-filter: blur(8px); margin-top: 0; }
.breadcrumb .container { display: flex; flex-wrap: wrap; gap: 6px; }
.breadcrumb a { color: #1a3a5c; }
.breadcrumb span { color: #999; }

/* 通用section - 毛玻璃卡片背景 */
.section { padding: 60px 0; background: rgba(255, 255, 255, 0.7); backdrop-filter: blur(6px); -webkit-backdrop-filter: blur(6px); margin: 20px 0; border-radius: 24px; box-shadow: 0 8px 32px rgba(0,0,0,0.06); }
.section:nth-child(even) { background: rgba(248, 249, 250, 0.7); backdrop-filter: blur(6px); -webkit-backdrop-filter: blur(6px); }
.section-title { text-align: center; margin-bottom: 40px; }
.section-title h2 { font-size: 2rem; color: #1a3a5c; margin-bottom: 10px; }
.section-title p { color: #555; max-width: 700px; margin: 0 auto; }

/* 按钮 - 渐变与hover动画 */
.btn { display: inline-block; background: linear-gradient(135deg, #1a3a5c, #2a5a7c); color: #fff; padding: 10px 28px; border-radius: 30px; font-size: 0.95rem; transition: all 0.3s ease; border: none; cursor: pointer; }
.btn:hover { background: linear-gradient(135deg, #2a4a6c, #3a6a8c); transform: translateY(-2px) scale(1.02); box-shadow: 0 4px 12px rgba(26,58,92,0.3); }

/* 卡片网格 */
.grid-3 { display: grid; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); gap: 30px; }
.grid-2 { display: grid; grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); gap: 30px; }

/* 圆角卡片 - 毛玻璃效果 */
.card { background: rgba(255, 255, 255, 0.8); backdrop-filter: blur(10px); -webkit-backdrop-filter: blur(10px); border-radius: 16px; padding: 24px; box-shadow: 0 2px 12px rgba(0,0,0,0.06); transition: all 0.3s ease; border: 1px solid rgba(255,255,255,0.3); }
.card:hover { box-shadow: 0 6px 20px rgba(0,0,0,0.1); transform: translateY(-4px) scale(1.01); background: rgba(255, 255, 255, 0.9); }
.card svg { width: 48px; height: 48px; margin-bottom: 16px; }
.card h3 { font-size: 1.2rem; margin-bottom: 10px; }
.card p { color: #555; font-size: 0.95rem; }

/* 文章卡片 - 毛玻璃效果 */
.article-card { background: rgba(255, 255, 255, 0.8); backdrop-filter: blur(10px); -webkit-backdrop-filter: blur(10px); border-radius: 16px; overflow: hidden; box-shadow: 0 2px 10px rgba(0,0,0,0.05); transition: all 0.3s ease; border: 1px solid rgba(255,255,255,0.3); }
.article-card:hover { box-shadow: 0 4px 16px rgba(0,0,0,0.1); transform: translateY(-4px); background: rgba(255, 255, 255, 0.9); }
.article-card .content { padding: 20px; }
.article-card h3 { font-size: 1.1rem; margin-bottom: 6px; }
.article-card .meta { font-size: 0.8rem; color: #888; margin-bottom: 8px; }
.article-card p { color: #555; font-size: 0.9rem; }
.article-card .read-more { color: #1a3a5c; font-weight: 600; display: inline-block; margin-top: 8px; transition: color 0.2s; }
.article-card .read-more:hover { color: #2a5a7c; }

/* FAQ */
.faq-item { border-bottom: 1px solid #e0e0e0; padding: 14px 0; }
.faq-question { display: flex; justify-content: space-between; align-items: center; cursor: pointer; font-weight: 600; font-size: 1rem; }
.faq-question span { font-size: 1.2rem; transition: 0.3s; }
.faq-answer { max-height: 0; overflow: hidden; transition: max-height 0.4s ease; padding-top: 0; }
.faq-answer.open { max-height: 500px; padding-top: 12px; }
.faq-answer p { color: #444; line-height: 1.7; }

/* HowTo步骤 - 毛玻璃效果 */
.step { background: rgba(255, 255, 255, 0.8); backdrop-filter: blur(8px); -webkit-backdrop-filter: blur(8px); border-left: 4px solid #1a3a5c; padding: 16px 20px; margin-bottom: 16px; border-radius: 0 12px 12px 0; transition: all 0.3s; }
.step:hover { background: rgba(255, 255, 255, 0.95); transform: translateX(4px); }
.step h4 { font-size: 1.1rem; margin-bottom: 6px; }
.step p { color: #555; }

/* 页脚 */
.footer { background: #1a1a2e; color: #ccc; padding: 40px 0 20px; }
.footer .container { display: grid; grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); gap: 30px; }
.footer h4 { color: #fff; margin-bottom: 12px; }
.footer a { color: #aaa; display: block; margin-bottom: 6px; }
.footer a:hover { color: #fff; }
.footer .copyright { grid-column: 1 / -1; text-align: center; padding-top: 20px; border-top: 1px solid #333; margin-top: 20px; font-size: 0.85rem; }

/* 返回顶部 - 毛玻璃效果 */
.back-to-top { position: fixed; bottom: 30px; right: 30px; background: rgba(26, 58, 92, 0.85); backdrop-filter: blur(8px); -webkit-backdrop-filter: blur(8px); color: #fff; width: 44px; height: 44px; border-radius: 50%; display: flex; align-items: center; justify-content: center; cursor: pointer; opacity: 0; visibility: hidden; transition: all 0.3s; border: none; font-size: 1.2rem; z-index: 999; }
.back-to-top.visible { opacity: 1; visibility: visible; }
.back-to-top:hover { background: rgba(26, 58, 92, 1); transform: scale(1.1); }

/* 轮播 - 渐变Banner */
.carousel { position: relative; overflow: hidden; width: 100%; height: 420px; background: linear-gradient(135deg, #eef2f7 0%, #d4dce8 100%); border-radius: 24px; margin: 20px 0; }
.carousel-slide { display: flex; transition: transform 0.5s ease; height: 100%; }
.carousel-item { min-width: 100%; height: 100%; display: flex; align-items: center; justify-content: center; flex-direction: column; padding: 40px; text-align: center; background: linear-gradient(135deg, rgba(26,58,92,0.05) 0%, rgba(42,90,124,0.1) 100%); }
.carousel-item h1 { font-size: 2.5rem; color: #1a3a5c; margin-bottom: 16px; text-shadow: 0 2px 4px rgba(0,0,0,0.1); }
.carousel-item p { font-size: 1.1rem; color: #444; max-width: 600px; }
.carousel-controls { position: absolute; top: 50%; width: 100%; display: flex; justify-content: space-between; transform: translateY(-50%); padding: 0 20px; }
.carousel-controls button { background: rgba(26,58,92,0.7); color: #fff; border: none; width: 44px; height: 44px; border-radius: 50%; cursor: pointer; font-size: 1.2rem; transition: 0.2s; backdrop-filter: blur(4px); -webkit-backdrop-filter: blur(4px); }
.carousel-controls button:hover { background: #1a3a5c; transform: scale(1.1); }
.carousel-dots { position: absolute; bottom: 20px; left: 50%; transform: translateX(-50%); display: flex; gap: 10px; }
.carousel-dots span { width: 12px; height: 12px; border-radius: 50%; background: #ccc; cursor: pointer; transition: 0.2s; }
.carousel-dots span.active { background: #1a3a5c; }

/* 移动菜单 */
@media (max-width: 768px) {
    .nav { display: none; flex-direction: column; width: 100%; background: rgba(255, 255, 255, 0.95); backdrop-filter: blur(12px); -webkit-backdrop-filter: blur(12px); padding: 10px 0; border-radius: 0 0 16px 16px; }
    .nav.open { display: flex; }
    .menu-toggle { display: block; }
    .search-box input { width: 120px; }
    .carousel { height: 300px; }
    .carousel-item h1 { font-size: 1.8rem; }
}

/* 数字动画 */
.stats { display: flex; justify-content: space-around; flex-wrap: wrap; gap: 20px; padding: 20px 0; }
.stat-item { text-align: center; }
.stat-number { font-size: 2.5rem; font-weight: 700; color: #1a3a5c; }
.stat-label { color: #555; font-size: 0.9rem; }

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

/* 图片懒加载占位 */
.lazy-placeholder { background: #e0e0e0; min-height: 100px; display: flex; align-items: center; justify-content: center; color: #999; border-radius: 12px; }

/* 友情链接、版权等 */
.friend-links { display: flex; flex-wrap: wrap; gap: 12px; justify-content: center; margin: 20px 0; }
.friend-links a { color: #1a3a5c; font-size: 0.9rem; }
.legal { font-size: 0.8rem; color: #888; text-align: center; margin-top: 20px; }
.legal a { color: #888; margin: 0 8px; }

/* 联系信息 */
.contact-info { display: flex; flex-wrap: wrap; gap: 20px; justify-content: center; margin: 20px 0; }
.contact-info div { text-align: center; }
.contact-info svg { width: 32px; height: 32px; margin: 0 auto 8px; }

/* 资质 */
.cert-list { display: flex; flex-wrap: wrap; gap: 16px; justify-content: center; }
.cert-item { background: rgba(240, 244, 248, 0.8); backdrop-filter: blur(4px); -webkit-backdrop-filter: blur(4px); padding: 8px 16px; border-radius: 20px; font-size: 0.85rem; transition: all 0.2s; }
.cert-item:hover { background: rgba(240, 244, 248, 1); transform: scale(1.05); }