/* 基础重置与变量 */
* { margin: 0; padding: 0; box-sizing: border-box; }
body { font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans SC", sans-serif; line-height: 1.6; color: #1a1a2e; background: #ffffff; scroll-behavior: smooth; }
a { color: #1a3a5c; text-decoration: none; }
a:hover { color: #e67e22; }
img { max-width: 100%; height: auto; display: block; }
ul, ol { padding-left: 1.5rem; }
.container { max-width: 1200px; margin: 0 auto; padding: 0 20px; }
/* 导航吸顶 */
.site-header { position: sticky; top: 0; z-index: 1000; background: #ffffff; border-bottom: 1px solid #eaeaea; box-shadow: 0 2px 8px rgba(0,0,0,0.04); transition: background 0.3s; }
.header-inner { display: flex; align-items: center; justify-content: space-between; height: 64px; }
.logo { font-size: 1.5rem; font-weight: 700; color: #1a3a5c; display: flex; align-items: center; gap: 8px; }
.logo svg { width: 40px; height: 40px; }
.main-nav ul { display: flex; list-style: none; gap: 1.8rem; padding: 0; margin: 0; }
.main-nav a { font-size: 0.95rem; font-weight: 500; color: #2c3e50; padding: 4px 0; border-bottom: 2px solid transparent; transition: 0.2s; }
.main-nav a:hover, .main-nav a.active { color: #1a3a5c; border-bottom-color: #1a3a5c; }
.menu-toggle { display: none; background: none; border: none; font-size: 1.8rem; cursor: pointer; color: #1a3a5c; }
/* 移动菜单 */
@media (max-width: 768px) {
    .main-nav { display: none; position: absolute; top: 64px; left: 0; right: 0; background: #ffffff; border-bottom: 1px solid #eaeaea; padding: 1rem 20px; box-shadow: 0 4px 12px rgba(0,0,0,0.05); }
    .main-nav.open { display: block; }
    .main-nav ul { flex-direction: column; gap: 0.8rem; }
    .menu-toggle { display: block; }
}
/* 面包屑 */
.breadcrumb { background: #f5f7fa; padding: 12px 0; font-size: 0.9rem; color: #555; }
.breadcrumb a { color: #1a3a5c; }
.breadcrumb span { margin: 0 6px; color: #999; }
/* Banner 轮播 */
.banner-section { position: relative; overflow: hidden; background: linear-gradient(135deg, #eef2f7 0%, #dce3ed 100%); min-height: 400px; display: flex; align-items: center; }
.banner-slider { position: relative; width: 100%; }
.banner-slide { display: none; padding: 60px 0; text-align: center; }
.banner-slide.active { display: block; animation: fadeIn 0.8s ease; }
@keyframes fadeIn { from { opacity: 0; transform: translateY(10px); } to { opacity: 1; transform: translateY(0); } }
.banner-title { font-size: 2.4rem; font-weight: 700; color: #1a3a5c; margin-bottom: 1rem; }
.banner-desc { font-size: 1.2rem; color: #2c3e50; max-width: 700px; margin: 0 auto 1.5rem; }
.banner-btn { display: inline-block; background: #1a3a5c; color: #fff; padding: 12px 32px; border-radius: 40px; font-weight: 600; transition: 0.3s; }
.banner-btn:hover { background: #e67e22; color: #fff; }
.banner-dots { position: absolute; bottom: 20px; left: 50%; transform: translateX(-50%); display: flex; gap: 10px; }
.banner-dots span { width: 12px; height: 12px; border-radius: 50%; background: #ccc; cursor: pointer; transition: 0.3s; }
.banner-dots span.active { background: #1a3a5c; }
/* 通用标题 */
.section-title { text-align: center; margin-bottom: 2.5rem; }
.section-title h2 { font-size: 2rem; color: #1a3a5c; margin-bottom: 0.5rem; }
.section-title p { color: #5a6a7a; max-width: 600px; margin: 0 auto; }
/* 卡片网格 */
.grid-3 { display: grid; grid-template-columns: repeat(auto-fill, minmax(280px, 1fr)); gap: 24px; }
.card { background: rgba(255, 255, 255, 0.7); backdrop-filter: blur(10px); -webkit-backdrop-filter: blur(10px); border-radius: 16px; padding: 24px; transition: all 0.3s ease; border: 1px solid rgba(255, 255, 255, 0.3); box-shadow: 0 4px 12px rgba(0,0,0,0.05); }
.card:hover { transform: translateY(-8px) scale(1.02); box-shadow: 0 16px 32px rgba(0,0,0,0.1); border-color: rgba(26, 58, 92, 0.2); }
.card-icon { margin-bottom: 12px; }
.card h3 { font-size: 1.2rem; margin-bottom: 8px; color: #1a3a5c; }
.card p { color: #3d4a5a; font-size: 0.95rem; }
/* 文章列表 */
.article-list { display: grid; grid-template-columns: repeat(auto-fill, minmax(340px, 1fr)); gap: 24px; }
.article-item { background: #ffffff; border: 1px solid #eaeef3; border-radius: 12px; padding: 20px; transition: 0.3s; }
.article-item:hover { transform: translateY(-4px); box-shadow: 0 8px 20px rgba(0,0,0,0.08); }
.article-item h3 { font-size: 1.1rem; margin-bottom: 6px; }
.article-item .meta { font-size: 0.85rem; color: #7a8a9a; margin-bottom: 8px; }
.article-item p { color: #2c3e50; font-size: 0.95rem; }
.read-more { color: #1a3a5c; font-weight: 600; }
/* FAQ */
.faq-item { border-bottom: 1px solid #e8ecf1; padding: 16px 0; }
.faq-question { font-weight: 600; font-size: 1.05rem; cursor: pointer; display: flex; justify-content: space-between; align-items: center; color: #1a3a5c; }
.faq-question::after { content: '+'; font-size: 1.5rem; transition: 0.3s; }
.faq-item.open .faq-question::after { content: '−'; }
.faq-answer { max-height: 0; overflow: hidden; transition: max-height 0.4s ease, padding 0.3s; padding-top: 0; color: #3d4a5a; }
.faq-item.open .faq-answer { max-height: 600px; padding-top: 12px; }
/* HowTo */
.howto-step { display: flex; gap: 16px; margin-bottom: 20px; align-items: flex-start; }
.step-num { background: #1a3a5c; color: #fff; width: 32px; height: 32px; border-radius: 50%; display: flex; align-items: center; justify-content: center; font-weight: 700; flex-shrink: 0; }
/* 页脚 */
.site-footer { background: #1a1a2e; color: #ccd; padding: 40px 0 20px; margin-top: 60px; }
.footer-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(200px, 1fr)); gap: 30px; margin-bottom: 30px; }
.footer-col h4 { color: #fff; margin-bottom: 12px; font-size: 1.1rem; }
.footer-col a, .footer-col p { color: #aab; font-size: 0.9rem; display: block; margin-bottom: 6px; }
.footer-col a:hover { color: #e67e22; }
.footer-bottom { border-top: 1px solid #2a2a4e; padding-top: 20px; text-align: center; font-size: 0.85rem; color: #889; }
.footer-bottom a { color: #aab; }
/* 返回顶部 */
.back-to-top { position: fixed; bottom: 30px; right: 30px; background: #1a3a5c; color: #fff; width: 48px; height: 48px; border-radius: 50%; display: flex; align-items: center; justify-content: center; font-size: 1.5rem; cursor: pointer; opacity: 0; visibility: hidden; transition: 0.3s; border: none; z-index: 999; }
.back-to-top.visible { opacity: 0.9; visibility: visible; }
.back-to-top:hover { background: #e67e22; }
/* 暗黑模式 */
.dark-mode-toggle { background: none; border: 1px solid #ccc; border-radius: 30px; padding: 4px 12px; cursor: pointer; font-size: 0.9rem; color: #1a3a5c; }
body.dark { background: #121212; color: #e0e0e0; }
body.dark .site-header { background: #1e1e2e; border-bottom-color: #333; }
body.dark .card { background: rgba(30, 30, 46, 0.8); backdrop-filter: blur(10px); -webkit-backdrop-filter: blur(10px); border-color: #333; }
body.dark .article-item { background: #1e1e2e; border-color: #333; }
body.dark .breadcrumb { background: #1a1a2e; }
body.dark .banner-section { background: linear-gradient(135deg, #1a1a2e 0%, #2a2a4e 100%); }
body.dark .banner-title { color: #f0f0f0; }
body.dark .banner-desc { color: #ccc; }
body.dark .faq-item { border-color: #333; }
body.dark .faq-question { color: #e0e0e0; }
body.dark .section-title h2 { color: #f0f0f0; }
body.dark .section-title p { color: #aaa; }
body.dark .main-nav a { color: #ccc; }
body.dark .main-nav a:hover { color: #fff; }
body.dark .logo { color: #f0f0f0; }
/* 滚动动画 */
.scroll-animate { opacity: 0; transform: translateY(20px); transition: opacity 0.6s ease, transform 0.6s ease; }
.scroll-animate.visible { opacity: 1; transform: translateY(0); }
/* 搜索 */
.search-box { display: flex; gap: 8px; max-width: 400px; margin: 0 auto; }
.search-box input { flex: 1; padding: 10px 16px; border: 1px solid #d0d5dd; border-radius: 30px; font-size: 1rem; }
.search-box button { background: #1a3a5c; color: #fff; border: none; border-radius: 30px; padding: 10px 20px; cursor: pointer; font-weight: 600; }
.search-box button:hover { background: #e67e22; }
/* 图片懒加载占位 */
.lazy-placeholder { background: #eef2f7; min-height: 100px; }
/* 其他 */
.text-center { text-align: center; }
.mt-2 { margin-top: 2rem; }
.mb-2 { margin-bottom: 2rem; }
.gap-1 { gap: 1rem; }
.flex-center { display: flex; justify-content: center; align-items: center; }
.company-info p { margin-bottom: 6px; }
/* 响应式调整 */
@media (max-width: 768px) {
    .banner-title { font-size: 1.8rem; }
    .banner-desc { font-size: 1rem; }
    .section-title h2 { font-size: 1.6rem; }
    .grid-3 { grid-template-columns: 1fr; }
    .article-list { grid-template-columns: 1fr; }
    .footer-grid { grid-template-columns: 1fr; }
    .company-info, .contact-form { grid-column: 1; }
}
@media (max-width: 480px) {
    .banner-section { min-height: 300px; }
    .banner-slide { padding: 40px 0; }
    .banner-btn { padding: 10px 24px; font-size: 0.9rem; }
    .header-inner { height: 56px; }
    .logo { font-size: 1.2rem; }
    .logo svg { width: 32px; height: 32px; }
}