/* ============================================
   小蓝视频 - 原创样式表
   品牌色系：深蓝 #0A1628 | 主蓝 #1E90FF | 亮蓝 #00BFFF | 辅助青 #00CED1
   设计师：小蓝视频创意团队
   ============================================ */

/* === 基础重置与全局 === */
*, *::before, *::after { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; font-size: 16px; }
body {
  font-family: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  color: #2c3e50; background: #f8fafd; line-height: 1.75;
  -webkit-font-smoothing: antialiased;
}
a { color: #1E90FF; text-decoration: none; transition: color .25s; }
a:hover { color: #00BFFF; }
img { max-width: 100%; height: auto; display: block; }
ul, ol { list-style: none; }
.container { max-width: 1200px; margin: 0 auto; padding: 0 20px; }

/* === 顶部导航 === */
.site-header {
  position: fixed; top: 0; left: 0; width: 100%; z-index: 1000;
  background: rgba(10, 22, 40, 0.95); backdrop-filter: blur(12px);
  box-shadow: 0 2px 20px rgba(0,0,0,0.15); transition: background .3s;
}
.nav-wrap { display: flex; align-items: center; justify-content: space-between; height: 68px; }
.nav-logo { display: flex; align-items: center; gap: 10px; }
.nav-logo img { height: 40px; width: auto; }
.nav-logo span { color: #fff; font-size: 1.25rem; font-weight: 700; letter-spacing: 1px; }
.nav-menu { display: flex; align-items: center; gap: 6px; }
.nav-menu a {
  color: rgba(255,255,255,0.85); padding: 8px 16px; border-radius: 6px;
  font-size: 0.95rem; transition: all .25s; position: relative;
}
.nav-menu a:hover, .nav-menu a.active {
  color: #00BFFF; background: rgba(0,191,255,0.08);
}
.nav-menu a::after {
  content: ''; position: absolute; bottom: 2px; left: 50%; transform: translateX(-50%);
  width: 0; height: 2px; background: #00BFFF; transition: width .3s; border-radius: 1px;
}
.nav-menu a:hover::after, .nav-menu a.active::after { width: 60%; }

/* 搜索框 */
.search-bar {
  background: rgba(10, 22, 40, 0.6); border-bottom: 1px solid rgba(255,255,255,0.06);
  padding: 10px 0;
}
.search-inner {
  display: flex; align-items: center; justify-content: center; gap: 10px;
}
.search-inner input {
  width: 420px; max-width: 60vw; padding: 10px 18px; border: 1px solid rgba(30,144,255,0.3);
  border-radius: 24px; background: rgba(255,255,255,0.06); color: #fff;
  font-size: 0.9rem; outline: none; transition: border-color .3s;
}
.search-inner input::placeholder { color: rgba(255,255,255,0.4); }
.search-inner input:focus { border-color: #00BFFF; background: rgba(255,255,255,0.1); }
.search-inner button {
  padding: 10px 24px; background: linear-gradient(135deg, #1E90FF, #00BFFF);
  color: #fff; border: none; border-radius: 24px; cursor: pointer;
  font-size: 0.9rem; transition: transform .2s, box-shadow .2s;
}
.search-inner button:hover { transform: translateY(-1px); box-shadow: 0 4px 15px rgba(30,144,255,0.4); }

/* 移动端菜单 */
.mobile-toggle {
  display: none; background: none; border: none; cursor: pointer; padding: 8px;
}
.mobile-toggle span {
  display: block; width: 24px; height: 2px; background: #fff;
  margin: 5px 0; transition: all .3s; border-radius: 2px;
}

/* === Banner区域 === */
.hero-banner {
  position: relative; min-height: 600px; display: flex; align-items: center;
  justify-content: center; overflow: hidden; margin-top: 68px;
  background: linear-gradient(135deg, #0A1628 0%, #0d2137 50%, #0a2a4a 100%);
}
.hero-banner .bg-img {
  position: absolute; top: 0; left: 0; width: 100%; height: 100%;
  object-fit: cover; opacity: 0.35;
}
.hero-content {
  position: relative; z-index: 2; text-align: center; padding: 60px 20px;
  max-width: 800px;
}
.hero-content h1 {
  font-size: 2.8rem; color: #fff; margin-bottom: 16px;
  text-shadow: 0 2px 20px rgba(0,0,0,0.3); line-height: 1.3;
}
.hero-content h1 em {
  font-style: normal; color: #00BFFF;
  background: linear-gradient(90deg, #1E90FF, #00BFFF);
  -webkit-background-clip: text; -webkit-text-fill-color: transparent;
}
.hero-content p {
  font-size: 1.15rem; color: rgba(255,255,255,0.8); margin-bottom: 32px;
  line-height: 1.8;
}
.hero-btns { display: flex; gap: 16px; justify-content: center; flex-wrap: wrap; }
.btn-primary {
  display: inline-block; padding: 14px 36px; border-radius: 30px;
  background: linear-gradient(135deg, #1E90FF, #00BFFF); color: #fff;
  font-size: 1rem; font-weight: 600; transition: all .3s;
  box-shadow: 0 4px 20px rgba(30,144,255,0.35);
}
.btn-primary:hover {
  transform: translateY(-2px); box-shadow: 0 8px 30px rgba(30,144,255,0.5);
  color: #fff;
}
.btn-outline {
  display: inline-block; padding: 14px 36px; border-radius: 30px;
  border: 2px solid rgba(255,255,255,0.4); color: #fff;
  font-size: 1rem; font-weight: 600; transition: all .3s;
}
.btn-outline:hover {
  border-color: #00BFFF; background: rgba(0,191,255,0.1); color: #00BFFF;
}

/* === 通用区块 === */
.section { padding: 70px 0; }
.section-alt { background: #fff; }
.section-dark { background: #0A1628; color: #fff; }
.section-title {
  text-align: center; margin-bottom: 50px;
}
.section-title h2 {
  font-size: 2rem; color: #0A1628; margin-bottom: 12px;
  position: relative; display: inline-block;
}
.section-dark .section-title h2 { color: #fff; }
.section-title h2::after {
  content: ''; display: block; width: 60px; height: 3px; margin: 12px auto 0;
  background: linear-gradient(90deg, #1E90FF, #00BFFF); border-radius: 2px;
}
.section-title p { color: #6b7c93; font-size: 1.05rem; max-width: 600px; margin: 0 auto; }
.section-dark .section-title p { color: rgba(255,255,255,0.65); }

/* === 视频卡片网格 === */
.video-grid {
  display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px;
}
.video-card {
  background: #fff; border-radius: 12px; overflow: hidden;
  box-shadow: 0 4px 20px rgba(0,0,0,0.06); transition: all .35s;
  cursor: pointer;
}
.video-card:hover {
  transform: translateY(-6px); box-shadow: 0 12px 40px rgba(30,144,255,0.15);
}
.video-thumb {
  position: relative; overflow: hidden; aspect-ratio: 16/9;
}
.video-thumb img { width: 100%; height: 100%; object-fit: cover; transition: transform .5s; }
.video-card:hover .video-thumb img { transform: scale(1.05); }
.play-btn {
  position: absolute; top: 50%; left: 50%; transform: translate(-50%, -50%);
  width: 60px; height: 60px; background: rgba(30,144,255,0.85);
  border-radius: 50%; display: flex; align-items: center; justify-content: center;
  opacity: 0; transition: opacity .3s, transform .3s;
}
.play-btn::after {
  content: ''; width: 0; height: 0;
  border-left: 20px solid #fff; border-top: 12px solid transparent;
  border-bottom: 12px solid transparent; margin-left: 4px;
}
.video-card:hover .play-btn { opacity: 1; transform: translate(-50%, -50%) scale(1.1); }
.video-info { padding: 16px 18px; }
.video-info h3 { font-size: 1.05rem; color: #1a2332; margin-bottom: 8px; line-height: 1.5; }
.video-meta {
  display: flex; gap: 14px; font-size: 0.82rem; color: #8899aa;
}
.video-meta span { display: flex; align-items: center; gap: 4px; }
.video-tag {
  position: absolute; top: 12px; left: 12px; padding: 3px 10px;
  background: rgba(30,144,255,0.9); color: #fff; font-size: 0.75rem;
  border-radius: 4px; font-weight: 500;
}
.video-duration {
  position: absolute; bottom: 10px; right: 10px; padding: 2px 8px;
  background: rgba(0,0,0,0.7); color: #fff; font-size: 0.78rem;
  border-radius: 4px;
}

/* === 分类模块 === */
.category-grid {
  display: grid; grid-template-columns: repeat(4, 1fr); gap: 20px;
}
.category-card {
  text-align: center; padding: 30px 20px; background: #fff;
  border-radius: 12px; transition: all .3s;
  box-shadow: 0 2px 15px rgba(0,0,0,0.04);
}
.category-card:hover {
  transform: translateY(-4px); box-shadow: 0 8px 30px rgba(30,144,255,0.12);
}
.category-icon {
  width: 64px; height: 64px; margin: 0 auto 16px;
  background: linear-gradient(135deg, rgba(30,144,255,0.1), rgba(0,191,255,0.1));
  border-radius: 16px; display: flex; align-items: center; justify-content: center;
  font-size: 1.8rem;
}
.category-card h3 { font-size: 1.05rem; color: #1a2332; margin-bottom: 8px; }
.category-card p { font-size: 0.88rem; color: #6b7c93; line-height: 1.6; }

/* === 专家展示 === */
.expert-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 24px; }
.expert-card {
  background: #fff; border-radius: 12px; overflow: hidden; text-align: center;
  box-shadow: 0 4px 20px rgba(0,0,0,0.06); transition: all .35s;
}
.expert-card:hover { transform: translateY(-4px); box-shadow: 0 8px 30px rgba(30,144,255,0.12); }
.expert-avatar {
  width: 100%; aspect-ratio: 4/3; overflow: hidden;
}
.expert-avatar img { width: 100%; height: 100%; object-fit: cover; transition: transform .5s; }
.expert-card:hover .expert-avatar img { transform: scale(1.05); }
.expert-info { padding: 20px 16px; }
.expert-info h3 { font-size: 1.1rem; color: #1a2332; margin-bottom: 4px; }
.expert-info .role { color: #1E90FF; font-size: 0.88rem; margin-bottom: 10px; }
.expert-info p { font-size: 0.85rem; color: #6b7c93; line-height: 1.6; margin-bottom: 14px; }
.expert-btns { display: flex; gap: 8px; justify-content: center; }
.expert-btns a {
  padding: 6px 16px; border-radius: 20px; font-size: 0.82rem; font-weight: 500;
}
.expert-btns .btn-sm-primary {
  background: linear-gradient(135deg, #1E90FF, #00BFFF); color: #fff;
}
.expert-btns .btn-sm-outline {
  border: 1px solid #1E90FF; color: #1E90FF;
}

/* === FAQ区域 === */
.faq-list { max-width: 800px; margin: 0 auto; }
.faq-item {
  background: #fff; border-radius: 10px; margin-bottom: 12px;
  box-shadow: 0 2px 12px rgba(0,0,0,0.04); overflow: hidden;
}
.faq-question {
  padding: 18px 24px; cursor: pointer; display: flex;
  justify-content: space-between; align-items: center;
  font-weight: 600; color: #1a2332; font-size: 1rem;
  transition: background .2s;
}
.faq-question:hover { background: rgba(30,144,255,0.03); }
.faq-question .arrow {
  width: 24px; height: 24px; display: flex; align-items: center;
  justify-content: center; transition: transform .3s; color: #1E90FF;
  font-size: 1.2rem;
}
.faq-item.open .faq-question .arrow { transform: rotate(180deg); }
.faq-answer {
  max-height: 0; overflow: hidden; transition: max-height .4s ease;
  padding: 0 24px;
}
.faq-item.open .faq-answer { max-height: 300px; padding: 0 24px 18px; }
.faq-answer p { color: #5a6b7e; font-size: 0.95rem; line-height: 1.8; }

/* === 用户评论 === */
.review-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 24px; }
.review-card {
  background: #fff; border-radius: 12px; padding: 24px;
  box-shadow: 0 4px 20px rgba(0,0,0,0.05);
}
.review-header { display: flex; align-items: center; gap: 14px; margin-bottom: 14px; }
.review-avatar {
  width: 48px; height: 48px; border-radius: 50%;
  background: linear-gradient(135deg, #1E90FF, #00BFFF);
  display: flex; align-items: center; justify-content: center;
  color: #fff; font-weight: 700; font-size: 1.1rem;
}
.review-name { font-weight: 600; color: #1a2332; font-size: 0.95rem; }
.review-date { font-size: 0.8rem; color: #8899aa; }
.review-stars { color: #f5a623; font-size: 0.9rem; margin-bottom: 10px; }
.review-text { color: #5a6b7e; font-size: 0.92rem; line-height: 1.75; }

/* === 合作品牌墙 === */
.brand-wall {
  display: flex; flex-wrap: wrap; justify-content: center; gap: 30px;
  align-items: center;
}
.brand-wall .brand-item {
  width: 140px; height: 70px; background: #fff; border-radius: 10px;
  display: flex; align-items: center; justify-content: center;
  box-shadow: 0 2px 12px rgba(0,0,0,0.05); padding: 12px;
  font-size: 0.9rem; color: #6b7c93; font-weight: 600;
  transition: all .3s;
}
.brand-wall .brand-item:hover {
  box-shadow: 0 4px 20px rgba(30,144,255,0.15); transform: translateY(-2px);
}

/* === 页脚 === */
.site-footer {
  background: #0A1628; color: rgba(255,255,255,0.7); padding: 50px 0 0;
}
.footer-grid {
  display: grid; grid-template-columns: 2fr 1fr 1fr 1fr; gap: 40px;
  padding-bottom: 40px; border-bottom: 1px solid rgba(255,255,255,0.08);
}
.footer-brand img { height: 36px; margin-bottom: 14px; }
.footer-brand p { font-size: 0.9rem; line-height: 1.7; color: rgba(255,255,255,0.55); }
.footer-col h4 {
  color: #fff; font-size: 1rem; margin-bottom: 16px;
  position: relative; padding-bottom: 10px;
}
.footer-col h4::after {
  content: ''; position: absolute; bottom: 0; left: 0;
  width: 30px; height: 2px; background: #1E90FF;
}
.footer-col a {
  display: block; color: rgba(255,255,255,0.55); font-size: 0.88rem;
  padding: 5px 0; transition: color .2s;
}
.footer-col a:hover { color: #00BFFF; }
.footer-qr { display: flex; gap: 20px; margin-top: 16px; }
.footer-qr-item { text-align: center; }
.footer-qr-item img { width: 100px; height: 100px; border-radius: 6px; margin-bottom: 6px; }
.footer-qr-item span { font-size: 0.78rem; color: rgba(255,255,255,0.45); }
.footer-bottom {
  text-align: center; padding: 20px 0; font-size: 0.85rem;
  color: rgba(255,255,255,0.4);
}

/* === 面包屑 === */
.breadcrumb {
  padding: 14px 0; font-size: 0.88rem; color: #8899aa;
  margin-top: 68px;
}
.breadcrumb a { color: #1E90FF; }
.breadcrumb span { margin: 0 8px; color: #ccc; }

/* === 内页通用 === */
.page-hero {
  background: linear-gradient(135deg, #0A1628, #0d2137);
  padding: 100px 0 50px; text-align: center; margin-top: 68px;
}
.page-hero h1 { color: #fff; font-size: 2.2rem; margin-bottom: 12px; }
.page-hero p { color: rgba(255,255,255,0.65); font-size: 1.05rem; }
.content-wrap { padding: 50px 0; }
.content-wrap h2 { font-size: 1.6rem; color: #0A1628; margin-bottom: 16px; }
.content-wrap h3 { font-size: 1.3rem; color: #1a2332; margin: 24px 0 12px; }
.content-wrap p { color: #5a6b7e; line-height: 1.85; margin-bottom: 16px; }
.content-wrap ul { padding-left: 20px; margin-bottom: 16px; }
.content-wrap ul li {
  color: #5a6b7e; line-height: 1.85; padding: 4px 0;
  position: relative; padding-left: 16px;
}
.content-wrap ul li::before {
  content: ''; position: absolute; left: 0; top: 12px;
  width: 6px; height: 6px; background: #1E90FF; border-radius: 50%;
}

/* === 社交分享 === */
.share-bar {
  display: flex; gap: 10px; align-items: center; padding: 16px 0;
}
.share-bar span { font-size: 0.9rem; color: #6b7c93; }
.share-btn {
  width: 36px; height: 36px; border-radius: 50%; display: flex;
  align-items: center; justify-content: center; font-size: 0.85rem;
  color: #fff; transition: transform .2s; cursor: pointer;
}
.share-btn:hover { transform: scale(1.15); }
.share-wechat { background: #07c160; }
.share-weibo { background: #e6162d; }
.share-douyin { background: #161823; }
.share-bilibili { background: #00a1d6; }

/* === 联系信息 === */
.contact-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 30px; }
.contact-card {
  background: #fff; border-radius: 12px; padding: 30px;
  box-shadow: 0 4px 20px rgba(0,0,0,0.05);
}
.contact-card h3 { font-size: 1.2rem; color: #1a2332; margin-bottom: 16px; }
.contact-item { display: flex; gap: 12px; padding: 10px 0; align-items: flex-start; }
.contact-icon {
  width: 36px; height: 36px; background: rgba(30,144,255,0.1);
  border-radius: 8px; display: flex; align-items: center; justify-content: center;
  color: #1E90FF; font-size: 1rem; flex-shrink: 0;
}
.contact-detail { font-size: 0.92rem; color: #5a6b7e; }
.contact-detail strong { color: #1a2332; display: block; margin-bottom: 2px; }

/* === How-To指南 === */
.howto-steps { max-width: 700px; margin: 0 auto; }
.howto-step {
  display: flex; gap: 20px; padding: 20px 0;
  border-bottom: 1px solid #eef2f7;
}
.step-num {
  width: 44px; height: 44px; flex-shrink: 0;
  background: linear-gradient(135deg, #1E90FF, #00BFFF);
  border-radius: 50%; display: flex; align-items: center; justify-content: center;
  color: #fff; font-weight: 700; font-size: 1.1rem;
}
.step-content h4 { font-size: 1.05rem; color: #1a2332; margin-bottom: 6px; }
.step-content p { font-size: 0.92rem; color: #6b7c93; }

/* === 数据统计 === */
.stats-bar {
  display: flex; justify-content: center; gap: 60px; padding: 40px 0;
  flex-wrap: wrap;
}
.stat-item { text-align: center; }
.stat-num {
  font-size: 2.4rem; font-weight: 800;
  background: linear-gradient(135deg, #1E90FF, #00BFFF);
  -webkit-background-clip: text; -webkit-text-fill-color: transparent;
}
.stat-label { font-size: 0.9rem; color: rgba(255,255,255,0.6); margin-top: 4px; }

/* === 标签 === */
.tag-list { display: flex; flex-wrap: wrap; gap: 8px; margin: 12px 0; }
.tag {
  padding: 4px 14px; background: rgba(30,144,255,0.08); color: #1E90FF;
  border-radius: 16px; font-size: 0.82rem; transition: all .2s;
}
.tag:hover { background: #1E90FF; color: #fff; }

/* === 响应式 === */
@media (max-width: 1024px) {
  .video-grid { grid-template-columns: repeat(2, 1fr); }
  .category-grid { grid-template-columns: repeat(2, 1fr); }
  .expert-grid { grid-template-columns: repeat(2, 1fr); }
  .footer-grid { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 768px) {
  .nav-menu { display: none; }
  .mobile-toggle { display: block; }
  .nav-menu.open {
    display: flex; flex-direction: column; position: absolute;
    top: 68px; left: 0; width: 100%; background: rgba(10,22,40,0.98);
    padding: 20px; gap: 4px;
  }
  .hero-banner { min-height: 480px; }
  .hero-content h1 { font-size: 1.8rem; }
  .hero-content p { font-size: 1rem; }
  .video-grid { grid-template-columns: 1fr; }
  .category-grid { grid-template-columns: repeat(2, 1fr); }
  .expert-grid { grid-template-columns: 1fr; }
  .review-grid { grid-template-columns: 1fr; }
  .contact-grid { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr; }
  .stats-bar { gap: 30px; }
  .section { padding: 50px 0; }
  .section-title h2 { font-size: 1.6rem; }
}
@media (max-width: 480px) {
  .category-grid { grid-template-columns: 1fr; }
  .hero-btns { flex-direction: column; align-items: center; }
  .search-inner input { width: 100%; }
}