/* 全局重置与基础样式 */
* { margin: 0; padding: 0; box-sizing: border-box; }
body { font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif; background: #f8f9fa; color: #333; line-height: 1.8; }
a { color: #1a73e8; text-decoration: none; }
a:hover { color: #0d47a1; }
.container { max-width: 1200px; margin: 0 auto; padding: 0 20px; }

/* 导航吸顶 */
.navbar { position: sticky; top: 0; z-index: 1000; background: #2c3e50; color: #fff; padding: 15px 0; box-shadow: 0 2px 10px rgba(0,0,0,0.2); }
.navbar .container { display: flex; justify-content: space-between; align-items: center; }
.navbar .logo { font-size: 1.5rem; font-weight: bold; color: #fff; }
.navbar .logo span { color: #e74c3c; }
.navbar .nav-links { display: flex; gap: 25px; list-style: none; }
.navbar .nav-links a { color: #ecf0f1; font-size: 1rem; transition: color 0.3s; }
.navbar .nav-links a:hover { color: #e74c3c; }
.menu-toggle { display: none; background: none; border: none; color: #fff; font-size: 1.8rem; cursor: pointer; }
/* 返回顶部 */
.back-to-top { position: fixed; bottom: 30px; right: 30px; background: #2c3e50; color: #fff; width: 50px; height: 50px; border-radius: 50%; display: flex; align-items: center; justify-content: center; font-size: 1.5rem; cursor: pointer; opacity: 0; visibility: hidden; transition: all 0.3s; z-index: 999; border: none; }
.back-to-top.show { opacity: 1; visibility: visible; }
/* Banner轮播 */
.banner { position: relative; overflow: hidden; height: 450px; background: #34495e; }
.banner-slides { display: flex; transition: transform 0.6s ease; height: 100%; }
.banner-slide { min-width: 100%; height: 100%; display: flex; align-items: center; justify-content: center; color: #fff; text-align: center; padding: 40px; }
.banner-slide:nth-child(1) { background: linear-gradient(135deg, #1a2a6c, #b21f1f); }
.banner-slide:nth-child(2) { background: linear-gradient(135deg, #0f2027, #203a43, #2c5364); }
.banner-slide:nth-child(3) { background: linear-gradient(135deg, #4e4376, #dc2430); }
.banner-slide h1 { font-size: 2.8rem; margin-bottom: 20px; }
.banner-slide p { font-size: 1.2rem; max-width: 700px; margin: 0 auto; }
.banner-dots { position: absolute; bottom: 20px; left: 50%; transform: translateX(-50%); display: flex; gap: 12px; }
.banner-dots span { width: 14px; height: 14px; border-radius: 50%; background: rgba(255,255,255,0.5); cursor: pointer; transition: background 0.3s; }
.banner-dots span.active { background: #fff; }
/* 通用标题 */
.section-title { text-align: center; margin: 60px 0 40px; }
.section-title h2 { font-size: 2.2rem; color: #2c3e50; position: relative; display: inline-block; padding-bottom: 15px; }
.section-title h2::after { content: ''; position: absolute; bottom: 0; left: 50%; transform: translateX(-50%); width: 60px; height: 4px; background: #e74c3c; border-radius: 2px; }
.section-title p { color: #666; margin-top: 10px; font-size: 1.1rem; }
/* 文章卡片 */
.article-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(320px, 1fr)); gap: 30px; margin: 40px 0; }
.article-card { background: #fff; border-radius: 12px; overflow: hidden; box-shadow: 0 4px 15px rgba(0,0,0,0.08); transition: transform 0.3s, box-shadow 0.3s; }
.article-card:hover { transform: translateY(-5px); box-shadow: 0 8px 25px rgba(0,0,0,0.12); }
.article-card .card-img { height: 200px; background: #e0e0e0; display: flex; align-items: center; justify-content: center; }
.article-card .card-img svg { width: 80px; height: 80px; opacity: 0.6; }
.article-card .card-body { padding: 25px; }
.article-card .card-body h3 { font-size: 1.3rem; margin-bottom: 10px; color: #2c3e50; }
.article-card .card-body .meta { color: #999; font-size: 0.9rem; margin-bottom: 12px; }
.article-card .card-body p { color: #555; margin-bottom: 15px; }
.article-card .card-body .read-more { color: #e74c3c; font-weight: 600; }
/* FAQ */
.faq-list { max-width: 900px; margin: 0 auto 60px; }
.faq-item { background: #fff; border-radius: 10px; margin-bottom: 15px; box-shadow: 0 2px 10px rgba(0,0,0,0.05); overflow: hidden; }
.faq-question { padding: 20px 25px; font-size: 1.1rem; font-weight: 600; cursor: pointer; display: flex; justify-content: space-between; align-items: center; transition: background 0.3s; }
.faq-question:hover { background: #f1f3f5; }
.faq-question .icon { font-size: 1.5rem; transition: transform 0.3s; }
.faq-question.active .icon { transform: rotate(45deg); }
.faq-answer { padding: 0 25px 20px; display: none; color: #555; line-height: 1.9; }
.faq-answer.show { display: block; }
/* HowTo */
.howto-section { background: #fff; border-radius: 16px; padding: 40px; margin: 40px 0; box-shadow: 0 4px 20px rgba(0,0,0,0.06); }
.howto-section h2 { font-size: 2rem; margin-bottom: 30px; color: #2c3e50; }
.howto-step { display: flex; gap: 20px; margin-bottom: 30px; align-items: flex-start; }
.howto-step .step-num { background: #e74c3c; color: #fff; width: 40px; height: 40px; border-radius: 50%; display: flex; align-items: center; justify-content: center; font-weight: bold; font-size: 1.2rem; flex-shrink: 0; }
.howto-step .step-content h4 { font-size: 1.2rem; margin-bottom: 8px; color: #2c3e50; }
.howto-step .step-content p { color: #555; }
/* 企业信息 */
.company-info { display: grid; grid-template-columns: repeat(auto-fill, minmax(250px, 1fr)); gap: 20px; background: #2c3e50; color: #ecf0f1; padding: 40px; border-radius: 16px; margin: 40px 0; }
.company-info h3 { color: #e74c3c; margin-bottom: 15px; font-size: 1.3rem; }
.company-info p { margin-bottom: 8px; }
.company-info a { color: #e74c3c; }
/* 友情链接 */
.friend-links { display: flex; flex-wrap: wrap; gap: 20px; justify-content: center; margin: 40px 0; padding: 20px 0; border-top: 1px solid #ddd; }
.friend-links a { color: #555; font-size: 0.95rem; }
/* 页脚 */
footer { background: #1a252f; color: #bdc3c7; text-align: center; padding: 30px 0; margin-top: 60px; }
footer p { margin: 5px 0; font-size: 0.9rem; }
/* 数字动画 */
.stats { display: flex; justify-content: space-around; flex-wrap: wrap; gap: 30px; margin: 50px 0; }
.stat-item { text-align: center; }
.stat-item .number { font-size: 3rem; font-weight: bold; color: #e74c3c; }
.stat-item .label { color: #666; font-size: 1.1rem; }
/* 移动端适配 */
@media (max-width: 768px) {
    .navbar .nav-links { display: none; flex-direction: column; background: #2c3e50; position: absolute; top: 60px; left: 0; width: 100%; padding: 20px; gap: 15px; }
    .navbar .nav-links.open { display: flex; }
    .menu-toggle { display: block; }
    .banner { height: 300px; }
    .banner-slide h1 { font-size: 1.8rem; }
    .banner-slide p { font-size: 1rem; }
    .section-title h2 { font-size: 1.6rem; }
    .article-grid { grid-template-columns: 1fr; }
    .howto-section { padding: 20px; }
    .company-info { grid-template-columns: 1fr; }
}
/* 滚动动画 */
.fade-in { opacity: 0; transform: translateY(30px); transition: opacity 0.6s, transform 0.6s; }
.fade-in.visible { opacity: 1; transform: translateY(0); }
/* 暗黑模式 */
.dark-mode { background: #1a1a2e; color: #e0e0e0; }
.dark-mode .navbar { background: #16213e; }
.dark-mode .article-card { background: #16213e; color: #e0e0e0; }
.dark-mode .article-card .card-body p { color: #bbb; }
.dark-mode .faq-item { background: #16213e; }
.dark-mode .howto-section { background: #16213e; }
.dark-mode .company-info { background: #0f3460; }
.dark-mode .friend-links a { color: #aaa; }
.dark-mode .back-to-top { background: #0f3460; }
.dark-mode-toggle { background: none; border: 1px solid #fff; color: #fff; padding: 8px 16px; border-radius: 20px; cursor: pointer; font-size: 0.9rem; }
/* 搜索 */
.search-box { display: flex; gap: 10px; }
.search-box input { padding: 8px 15px; border-radius: 20px; border: 1px solid #ddd; outline: none; width: 200px; }
.search-box button { background: #e74c3c; color: #fff; border: none; padding: 8px 15px; border-radius: 20px; cursor: pointer; }
@media (max-width: 768px) {
    .search-box input { width: 130px; }
}