/* ============================================
   暗网修车改装视频社区 | y44kkt.cn
   原创CSS样式 - 深空赛道主题
   ============================================ */

/* ===== CSS变量 ===== */
:root {
  --primary: #FF5500;
  --primary-dark: #CC4400;
  --primary-light: rgba(255,85,0,0.12);
  --secondary: #1A1A2E;
  --accent: #E8B800;
  --bg-dark: #0D0D1A;
  --bg-card: #16162A;
  --bg-card2: #1E1E38;
  --text: #F0F0F0;
  --text-muted: #8888AA;
  --text-dim: #5A5A7A;
  --border: rgba(255,255,255,0.08);
  --border-hover: rgba(255,85,0,0.4);
  --radius: 12px;
  --radius-sm: 8px;
  --shadow: 0 4px 24px rgba(0,0,0,0.4);
  --shadow-hover: 0 8px 40px rgba(255,85,0,0.2);
  --transition: all 0.28s cubic-bezier(0.4,0,0.2,1);
  --header-h: 68px;
}

/* ===== 重置 ===== */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; font-size: 16px; }
body {
  font-family: -apple-system, 'PingFang SC', 'Microsoft YaHei', 'Hiragino Sans GB', sans-serif;
  background: var(--bg-dark);
  color: var(--text);
  line-height: 1.7;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}
a { color: inherit; text-decoration: none; transition: var(--transition); }
img { max-width: 100%; height: auto; display: block; }
ul, ol { list-style: none; }
button { cursor: pointer; border: none; background: none; font-family: inherit; }

/* ===== 公告栏 ===== */
.ns-s127i5ng {
  background: linear-gradient(90deg, var(--secondary), #12122A);
  border-bottom: 1px solid var(--border);
  height: 36px;
  overflow: hidden;
  position: relative;
  z-index: 200;
}
.ns-mzcztf {
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 24px;
  display: flex;
  align-items: center;
  height: 100%;
  gap: 16px;
}
.ns-6m99378s {
  background: var(--primary);
  color: #fff;
  font-size: 0.72rem;
  font-weight: 700;
  padding: 2px 10px;
  border-radius: 4px;
  white-space: nowrap;
  flex-shrink: 0;
}
.ns-bq6pgn { overflow: hidden; flex: 1; }
.ns-ijqqf {
  font-size: 0.78rem;
  color: var(--text-muted);
  white-space: nowrap;
  display: inline-block;
  animation: scrollLeft 30s linear infinite;
}
@keyframes scrollLeft {
  0% { transform: translateX(100%); }
  100% { transform: translateX(-100%); }
}

/* ===== 顶部导航 ===== */
.site-header {
  position: fixed;
  top: 36px;
  left: 0;
  right: 0;
  height: var(--header-h);
  z-index: 100;
  background: rgba(13,13,26,0.85);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border);
  transition: var(--transition);
}
.site-header.scrolled {
  background: rgba(13,13,26,0.97);
  box-shadow: 0 4px 24px rgba(0,0,0,0.5);
}
.header-inner {
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 24px;
  height: 100%;
  display: flex;
  align-items: center;
  gap: 32px;
}
.logo-wrap {
  display: flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
  flex-shrink: 0;
}
.logo-img {
  width: 44px;
  height: 44px;
  border-radius: 10px;
  object-fit: cover;
}
.logo-text {
  font-size: 1.5rem;
  font-weight: 900;
  color: var(--primary);
  line-height: 1;
  display: block;
  letter-spacing: -1px;
}
.logo-sub {
  font-size: 0.68rem;
  color: var(--text-muted);
  display: block;
  line-height: 1;
  margin-top: 2px;
}
.main-nav {
  display: flex;
  align-items: center;
  gap: 4px;
  flex: 1;
}
.main-nav a {
  padding: 8px 14px;
  border-radius: var(--radius-sm);
  font-size: 0.88rem;
  font-weight: 600;
  color: var(--text-muted);
  transition: var(--transition);
  white-space: nowrap;
}
.main-nav a:hover, .main-nav a.active {
  color: var(--text);
  background: var(--primary-light);
}
.main-nav a.active { color: var(--primary); }
.header-actions { display: flex; align-items: center; gap: 12px; flex-shrink: 0; }
.btn-join {
  background: var(--primary) !important;
  color: #fff !important;
  padding: 8px 18px !important;
  border-radius: 20px !important;
  font-size: 0.85rem !important;
  font-weight: 700 !important;
}
.btn-join:hover { background: var(--primary-dark) !important; transform: translateY(-1px); }
.hamburger {
  display: none;
  flex-direction: column;
  gap: 5px;
  cursor: pointer;
  padding: 4px;
}
.hamburger span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--text);
  border-radius: 2px;
  transition: var(--transition);
}

/* ===== 移动端菜单 ===== */
.mobile-menu {
  display: none;
  position: fixed;
  top: 0;
  right: -100%;
  width: 280px;
  height: 100vh;
  background: var(--secondary);
  z-index: 999;
  padding: 80px 24px 40px;
  flex-direction: column;
  gap: 4px;
  transition: right 0.3s ease;
  border-left: 1px solid var(--border);
}
.mobile-menu.open { right: 0; }
.mobile-menu a {
  padding: 14px 16px;
  border-radius: var(--radius-sm);
  font-size: 1rem;
  font-weight: 600;
  color: var(--text-muted);
  border-bottom: 1px solid var(--border);
}
.mobile-menu a:hover { color: var(--primary); background: var(--primary-light); }
.mobile-close {
  position: absolute;
  top: 20px;
  right: 20px;
  font-size: 1.4rem;
  color: var(--text-muted);
  background: none;
  border: none;
  cursor: pointer;
}

/* ===== 搜索栏 ===== */
.search-bar-wrap {
  background: var(--secondary);
  border-bottom: 1px solid var(--border);
  padding: 14px 0;
}
.search-bar-inner {
  max-width: 900px;
  margin: 0 auto;
  padding: 0 24px;
}
.search-form {
  display: flex;
  gap: 0;
  border-radius: 28px;
  overflow: hidden;
  border: 1.5px solid var(--border);
  background: var(--bg-card);
  transition: var(--transition);
}
.search-form:focus-within {
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(255,85,0,0.15);
}
.search-form input {
  flex: 1;
  padding: 12px 20px;
  background: none;
  border: none;
  outline: none;
  color: var(--text);
  font-size: 0.9rem;
  font-family: inherit;
}
.search-form input::placeholder { color: var(--text-dim); }
.search-btn {
  padding: 10px 22px;
  background: var(--primary);
  color: #fff;
  border: none;
  font-size: 0.88rem;
  font-weight: 700;
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 6px;
  transition: var(--transition);
  font-family: inherit;
}
.search-btn:hover { background: var(--primary-dark); }
.search-tags {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
  margin-top: 10px;
}
.search-tag {
  font-size: 0.78rem;
  color: var(--text-muted);
  padding: 4px 12px;
  border-radius: 14px;
  border: 1px solid var(--border);
  cursor: pointer;
  transition: var(--transition);
}
.search-tag:hover { color: var(--primary); border-color: var(--primary); }

/* ===== HERO ===== */
.hero {
  position: relative;
  min-height: 100vh;
  display: flex;
  align-items: center;
  overflow: hidden;
}
.ns-jgqkz8s {
  position: absolute;
  inset: 0;
  background:
    url('../images/hero_banner.jpg') center/cover no-repeat;
  transform: scale(1.05);
  transition: transform 8s ease;
}
.hero:hover .ns-jgqkz8s { transform: scale(1.0); }
.ns-5gckop68 {
  position: absolute;
  inset: 0;
  background: linear-gradient(
    135deg,
    rgba(13,13,26,0.92) 0%,
    rgba(13,13,26,0.75) 50%,
    rgba(255,85,0,0.15) 100%
  );
}
.hero-content {
  position: relative;
  z-index: 2;
  max-width: 1280px;
  margin: 0 auto;
  padding: 120px 24px 80px;
  width: 100%;
}
.ns-82j61rm {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  background: rgba(255,85,0,0.15);
  border: 1px solid rgba(255,85,0,0.4);
  color: var(--primary);
  font-size: 0.78rem;
  font-weight: 700;
  padding: 6px 16px;
  border-radius: 20px;
  margin-bottom: 24px;
  letter-spacing: 0.5px;
}
.ns-82j61rm::before {
  content: '';
  width: 7px;
  height: 7px;
  background: var(--primary);
  border-radius: 50%;
  animation: pulse 1.5s ease-in-out infinite;
}
@keyframes pulse {
  0%, 100% { opacity: 1; transform: scale(1); }
  50% { opacity: 0.5; transform: scale(1.4); }
}
.hero h1 {
  font-size: clamp(2.4rem, 6vw, 4.5rem);
  font-weight: 900;
  line-height: 1.15;
  margin-bottom: 20px;
  letter-spacing: -1px;
}
.hero h1 .brand { color: var(--primary); }
.hero h1 .highlight {
  background: linear-gradient(90deg, var(--primary), var(--accent));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}
.hero-desc {
  font-size: 1.05rem;
  color: rgba(240,240,240,0.8);
  max-width: 640px;
  line-height: 1.8;
  margin-bottom: 36px;
}
.hero-desc strong { color: var(--primary); font-weight: 700; }
.hero-actions {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
  margin-bottom: 56px;
}
.btn-primary {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: var(--primary);
  color: #fff;
  padding: 14px 28px;
  border-radius: 28px;
  font-size: 0.95rem;
  font-weight: 700;
  transition: var(--transition);
  box-shadow: 0 4px 20px rgba(255,85,0,0.4);
  border: none;
  cursor: pointer;
}
.btn-primary:hover {
  background: var(--primary-dark);
  transform: translateY(-2px);
  box-shadow: 0 8px 32px rgba(255,85,0,0.5);
}
.btn-outline {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: transparent;
  color: var(--text);
  padding: 14px 28px;
  border-radius: 28px;
  font-size: 0.95rem;
  font-weight: 700;
  border: 1.5px solid rgba(255,255,255,0.3);
  transition: var(--transition);
}
.btn-outline:hover {
  border-color: var(--primary);
  color: var(--primary);
  background: var(--primary-light);
}
.hero-stats {
  display: flex;
  gap: 40px;
  flex-wrap: wrap;
}
.stat-item { text-align: center; }
.stat-num {
  display: block;
  font-size: 1.8rem;
  font-weight: 900;
  color: var(--primary);
  line-height: 1;
  margin-bottom: 4px;
}
.stat-label {
  font-size: 0.78rem;
  color: var(--text-muted);
}

/* ===== 通用Section ===== */
.section {
  padding: 80px 0;
}
.section-alt {
  background: var(--secondary);
}
.container {
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 24px;
}
.section-head {
  text-align: center;
  margin-bottom: 48px;
}
.section-tag {
  display: inline-block;
  background: var(--primary-light);
  color: var(--primary);
  font-size: 0.78rem;
  font-weight: 700;
  padding: 4px 14px;
  border-radius: 14px;
  margin-bottom: 12px;
  border: 1px solid rgba(255,85,0,0.2);
  letter-spacing: 0.5px;
}
.section-title {
  font-size: clamp(1.4rem, 3vw, 2rem);
  font-weight: 900;
  margin-bottom: 12px;
  line-height: 1.3;
}
.section-desc {
  font-size: 0.92rem;
  color: var(--text-muted);
  max-width: 600px;
  margin: 0 auto;
  line-height: 1.7;
}

/* ===== 分类卡片 ===== */
.cat-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(140px, 1fr));
  gap: 16px;
}
.cat-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px 16px;
  text-align: center;
  cursor: pointer;
  transition: var(--transition);
  display: block;
  text-decoration: none;
}
.cat-card:hover {
  border-color: var(--primary);
  background: var(--bg-card2);
  transform: translateY(-4px);
  box-shadow: var(--shadow-hover);
}
.cat-icon { font-size: 2rem; display: block; margin-bottom: 10px; }
.cat-name { font-size: 0.88rem; font-weight: 700; margin-bottom: 4px; }
.cat-count { font-size: 0.75rem; color: var(--text-muted); }

/* ===== 视频卡片 ===== */
.video-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 20px;
}
.video-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  cursor: pointer;
  transition: var(--transition);
}
.video-card:hover {
  border-color: var(--border-hover);
  transform: translateY(-4px);
  box-shadow: var(--shadow-hover);
}
.video-thumb {
  position: relative;
  aspect-ratio: 16/9;
  overflow: hidden;
  background: var(--bg-card2);
}
.video-thumb img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.4s ease;
}
.video-card:hover .video-thumb img { transform: scale(1.06); }
.play-btn {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(0,0,0,0.3);
  opacity: 0;
  transition: var(--transition);
}
.video-card:hover .play-btn { opacity: 1; }
.play-icon {
  width: 52px;
  height: 52px;
  background: rgba(255,85,0,0.9);
  border-radius: 50%;
  position: relative;
  box-shadow: 0 4px 20px rgba(255,85,0,0.5);
  transition: var(--transition);
}
.play-icon::after {
  content: '';
  position: absolute;
  top: 50%;
  left: 55%;
  transform: translate(-50%, -50%);
  border: 0 solid transparent;
  border-left: 18px solid #fff;
  border-top: 11px solid transparent;
  border-bottom: 11px solid transparent;
}
.play-icon:hover { transform: scale(1.1); }
.video-duration {
  position: absolute;
  bottom: 8px;
  right: 8px;
  background: rgba(0,0,0,0.8);
  color: #fff;
  font-size: 0.72rem;
  font-weight: 700;
  padding: 2px 8px;
  border-radius: 4px;
}
.video-tag {
  position: absolute;
  top: 8px;
  left: 8px;
  background: var(--primary);
  color: #fff;
  font-size: 0.68rem;
  font-weight: 700;
  padding: 2px 8px;
  border-radius: 4px;
}
.video-info { padding: 14px 16px; }
.video-title {
  font-size: 0.9rem;
  font-weight: 700;
  line-height: 1.5;
  margin-bottom: 8px;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}
.video-meta {
  display: flex;
  gap: 12px;
  font-size: 0.75rem;
  color: var(--text-muted);
  margin-bottom: 6px;
  align-items: center;
}
.video-meta svg { vertical-align: middle; margin-right: 3px; }
.video-stats {
  display: flex;
  gap: 14px;
  font-size: 0.75rem;
  color: var(--text-dim);
}

/* ===== 精选视频布局 ===== */
.featured-grid {
  display: grid;
  grid-template-columns: 1.6fr 1fr;
  gap: 20px;
}
.featured-main .video-thumb { aspect-ratio: 16/9; }
.featured-main .video-title { font-size: 1.05rem; }
.featured-side {
  display: flex;
  flex-direction: column;
  gap: 16px;
}
.featured-side .video-thumb { aspect-ratio: 16/9; }
.featured-side .video-title { font-size: 0.85rem; }

/* ===== AI赋能 ===== */
.ai-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 48px;
  align-items: center;
}
.ai-img img {
  width: 100%;
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}
.ai-features {
  display: flex;
  flex-direction: column;
  gap: 20px;
  margin-top: 24px;
}
.ai-feature {
  display: flex;
  gap: 16px;
  align-items: flex-start;
}
.ai-feature-icon {
  font-size: 1.5rem;
  flex-shrink: 0;
  width: 44px;
  height: 44px;
  background: var(--primary-light);
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  border: 1px solid rgba(255,85,0,0.2);
}
.ai-feature-title {
  font-size: 0.92rem;
  font-weight: 700;
  margin-bottom: 4px;
}
.ai-feature-desc {
  font-size: 0.82rem;
  color: var(--text-muted);
  line-height: 1.6;
}

/* ===== 专家卡片 ===== */
.experts-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 24px;
}
.expert-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  transition: var(--transition);
}
.expert-card:hover {
  border-color: var(--border-hover);
  transform: translateY(-4px);
  box-shadow: var(--shadow-hover);
}
.expert-img-wrap {
  position: relative;
  aspect-ratio: 4/3;
  overflow: hidden;
}
.expert-img-wrap img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.4s ease;
}
.expert-card:hover .expert-img-wrap img { transform: scale(1.05); }
.expert-badge {
  position: absolute;
  top: 12px;
  right: 12px;
  background: var(--primary);
  color: #fff;
  font-size: 0.72rem;
  font-weight: 700;
  padding: 4px 10px;
  border-radius: 14px;
}
.expert-info { padding: 16px; }
.expert-name {
  font-size: 1.1rem;
  font-weight: 800;
  margin-bottom: 4px;
}
.expert-role {
  font-size: 0.78rem;
  color: var(--primary);
  font-weight: 600;
  margin-bottom: 10px;
}
.expert-desc {
  font-size: 0.82rem;
  color: var(--text-muted);
  line-height: 1.6;
  margin-bottom: 12px;
  display: -webkit-box;
  -webkit-line-clamp: 3;
  -webkit-box-orient: vertical;
  overflow: hidden;
}
.expert-awards {
  display: flex;
  gap: 6px;
  flex-wrap: wrap;
  margin-bottom: 14px;
}
.award-tag {
  font-size: 0.7rem;
  background: rgba(232,184,0,0.1);
  color: var(--accent);
  border: 1px solid rgba(232,184,0,0.2);
  padding: 2px 8px;
  border-radius: 10px;
}
.expert-actions { display: flex; gap: 8px; }
.btn-sm {
  padding: 7px 16px;
  border-radius: 16px;
  font-size: 0.8rem;
  font-weight: 700;
  transition: var(--transition);
  cursor: pointer;
  font-family: inherit;
}
.btn-sm-primary { background: var(--primary); color: #fff; }
.btn-sm-primary:hover { background: var(--primary-dark); }
.btn-sm-outline { background: transparent; color: var(--text-muted); border: 1px solid var(--border); }
.btn-sm-outline:hover { border-color: var(--primary); color: var(--primary); }

/* ===== 社区 ===== */
.community-banner {
  position: relative;
  border-radius: var(--radius);
  overflow: hidden;
  margin-bottom: 48px;
  aspect-ratio: 21/6;
}
.community-banner img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}
.community-banner-text {
  position: absolute;
  inset: 0;
  background: linear-gradient(90deg, rgba(13,13,26,0.9), rgba(13,13,26,0.4));
  display: flex;
  flex-direction: column;
  justify-content: center;
  padding: 40px;
}
.community-banner-text h2 { font-size: 1.8rem; font-weight: 900; margin-bottom: 8px; }
.community-banner-text p { font-size: 0.9rem; color: var(--text-muted); }
.join-steps {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
}
.join-step {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px;
  text-align: center;
  transition: var(--transition);
}
.join-step:hover { border-color: var(--primary); transform: translateY(-4px); }
.step-num {
  width: 44px;
  height: 44px;
  background: var(--primary);
  color: #fff;
  font-size: 1.2rem;
  font-weight: 900;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 14px;
}
.step-title { font-size: 0.95rem; font-weight: 700; margin-bottom: 8px; }
.step-desc { font-size: 0.8rem; color: var(--text-muted); line-height: 1.6; }

/* ===== 合作品牌 ===== */
.partners-grid {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 16px;
}
.partner-logo {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 20px 16px;
  text-align: center;
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--text-muted);
  transition: var(--transition);
  cursor: default;
}
.partner-logo:hover {
  border-color: var(--primary);
  color: var(--primary);
  background: var(--primary-light);
}

/* ===== 用户评价 ===== */
.reviews-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 20px;
}
.review-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px;
  transition: var(--transition);
}
.review-card:hover { border-color: var(--border-hover); transform: translateY(-2px); }
.review-stars { color: var(--accent); font-size: 0.9rem; margin-bottom: 10px; }
.review-text {
  font-size: 0.88rem;
  color: var(--text-muted);
  line-height: 1.7;
  margin-bottom: 16px;
  font-style: italic;
}
.review-author { display: flex; align-items: center; gap: 10px; }
.review-avatar {
  width: 36px;
  height: 36px;
  background: var(--primary);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.9rem;
  font-weight: 700;
  color: #fff;
  flex-shrink: 0;
}
.review-name { font-size: 0.88rem; font-weight: 700; }
.review-date { font-size: 0.75rem; color: var(--text-dim); }

/* ===== 联系 ===== */
.contact-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 32px;
}
.contact-info-block {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 28px;
}
.contact-info-block h3 {
  font-size: 1rem;
  font-weight: 800;
  margin-bottom: 20px;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--border);
}
.contact-item {
  display: flex;
  gap: 14px;
  align-items: flex-start;
  margin-bottom: 16px;
}
.contact-icon {
  font-size: 1.2rem;
  flex-shrink: 0;
  width: 36px;
  height: 36px;
  background: var(--primary-light);
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
}
.contact-label { font-size: 0.75rem; color: var(--text-muted); margin-bottom: 2px; }
.contact-val { font-size: 0.9rem; font-weight: 600; }
.qr-row { display: flex; gap: 20px; }
.qr-item { text-align: center; }
.qr-item img { border-radius: 8px; border: 1px solid var(--border); }
.qr-label { font-size: 0.72rem; color: var(--text-muted); margin-top: 6px; }

/* ===== FAQ ===== */
.faq-list {
  max-width: 800px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 12px;
}
.faq-item {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  transition: var(--transition);
}
.faq-item.open { border-color: var(--primary); }
.faq-q {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 18px 20px;
  cursor: pointer;
  font-size: 0.92rem;
  font-weight: 700;
  gap: 12px;
  transition: var(--transition);
}
.faq-q:hover { color: var(--primary); }
.faq-item.open .faq-q { color: var(--primary); }
.faq-arrow {
  font-size: 0.7rem;
  color: var(--text-muted);
  transition: transform 0.3s ease;
  flex-shrink: 0;
}
.faq-item.open .faq-arrow { transform: rotate(180deg); color: var(--primary); }
.faq-a {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.35s ease, padding 0.35s ease;
  font-size: 0.88rem;
  color: var(--text-muted);
  line-height: 1.7;
  padding: 0 20px;
}
.faq-item.open .faq-a { max-height: 200px; padding: 0 20px 18px; }

/* ===== 标签云 ===== */
.tag-cloud {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}
.tag {
  background: var(--bg-card);
  border: 1px solid var(--border);
  color: var(--text-muted);
  font-size: 0.82rem;
  padding: 6px 14px;
  border-radius: 16px;
  cursor: pointer;
  transition: var(--transition);
}
.tag:hover, .tag.active {
  background: var(--primary-light);
  border-color: var(--primary);
  color: var(--primary);
}

/* ===== 社交分享 ===== */
.social-share {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
  justify-content: center;
}
.share-btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 12px 24px;
  border-radius: 24px;
  font-size: 0.88rem;
  font-weight: 700;
  transition: var(--transition);
  cursor: pointer;
  border: 1.5px solid var(--border);
}
.share-wechat { color: #07C160; border-color: rgba(7,193,96,0.3); }
.share-wechat:hover { background: rgba(7,193,96,0.1); border-color: #07C160; }
.share-weibo { color: #E6162D; border-color: rgba(230,22,45,0.3); }
.share-weibo:hover { background: rgba(230,22,45,0.1); border-color: #E6162D; }
.share-douyin { color: #FE2C55; border-color: rgba(254,44,85,0.3); }
.share-douyin:hover { background: rgba(254,44,85,0.1); border-color: #FE2C55; }
.share-bilibili { color: #00A1D6; border-color: rgba(0,161,214,0.3); }
.share-bilibili:hover { background: rgba(0,161,214,0.1); border-color: #00A1D6; }

/* ===== 页脚 ===== */
.site-footer {
  background: #08081A;
  border-top: 1px solid var(--border);
  padding: 60px 0 24px;
}
.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1.5fr;
  gap: 40px;
  margin-bottom: 40px;
}
.footer-brand .logo-wrap { margin-bottom: 16px; }
.footer-desc {
  font-size: 0.82rem;
  color: var(--text-muted);
  line-height: 1.7;
  margin-bottom: 16px;
}
.footer-social { display: flex; gap: 10px; }
.social-icon {
  width: 34px;
  height: 34px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.78rem;
  font-weight: 700;
  color: var(--text-muted);
  transition: var(--transition);
}
.social-icon:hover { border-color: var(--primary); color: var(--primary); background: var(--primary-light); }
.footer-col h4 {
  font-size: 0.88rem;
  font-weight: 800;
  margin-bottom: 16px;
  color: var(--text);
  padding-bottom: 8px;
  border-bottom: 1px solid var(--border);
}
.footer-col ul { display: flex; flex-direction: column; gap: 10px; }
.footer-col ul li a {
  font-size: 0.82rem;
  color: var(--text-muted);
  transition: var(--transition);
}
.footer-col ul li a:hover { color: var(--primary); padding-left: 4px; }
.footer-bottom {
  border-top: 1px solid var(--border);
  padding-top: 20px;
  text-align: center;
}
.footer-bottom p {
  font-size: 0.78rem;
  color: var(--text-dim);
  margin-bottom: 4px;
}
.footer-bottom a { color: var(--primary); }
.update-time { font-size: 0.75rem; color: var(--text-dim); }

/* ===== 内页Hero ===== */
.page-hero {
  background: linear-gradient(135deg, var(--secondary), var(--bg-dark));
  border-bottom: 1px solid var(--border);
  padding: 100px 0 48px;
  text-align: center;
  margin-top: 104px;
}
.page-hero h1 {
  font-size: clamp(1.8rem, 4vw, 2.8rem);
  font-weight: 900;
  margin-bottom: 12px;
}
.page-hero p {
  font-size: 0.95rem;
  color: var(--text-muted);
  max-width: 600px;
  margin: 0 auto;
}
.breadcrumb {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.82rem;
  color: var(--text-muted);
  margin-bottom: 20px;
}
.breadcrumb a { color: var(--text-muted); }
.breadcrumb a:hover { color: var(--primary); }
.breadcrumb .sep { color: var(--text-dim); }
.breadcrumb .current { color: var(--primary); }

/* ===== 分页 ===== */
.pagination {
  display: flex;
  justify-content: center;
  gap: 8px;
  margin-top: 48px;
}
.page-btn {
  width: 40px;
  height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 8px;
  font-size: 0.88rem;
  font-weight: 700;
  cursor: pointer;
  background: var(--bg-card);
  border: 1px solid var(--border);
  color: var(--text-muted);
  transition: var(--transition);
}
.page-btn:hover, .page-btn.active {
  background: var(--primary);
  border-color: var(--primary);
  color: #fff;
}

/* ===== 响应式 ===== */
@media (max-width: 1024px) {
  .featured-grid { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr 1fr; }
  .ai-grid { grid-template-columns: 1fr; }
  .join-steps { grid-template-columns: repeat(2, 1fr); }
  .partners-grid { grid-template-columns: repeat(4, 1fr); }
}

@media (max-width: 768px) {
  .main-nav { display: none; }
  .hamburger { display: flex; }
  .mobile-menu { display: flex; }
  .header-actions .btn-join { display: none; }
  .hero-stats { gap: 20px; }
  .stat-num { font-size: 1.4rem; }
  .cat-grid { grid-template-columns: repeat(3, 1fr); }
  .video-grid { grid-template-columns: 1fr; }
  .experts-grid { grid-template-columns: 1fr; }
  .contact-grid { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr; gap: 24px; }
  .join-steps { grid-template-columns: 1fr; }
  .partners-grid { grid-template-columns: repeat(3, 1fr); }
  .reviews-grid { grid-template-columns: 1fr; }
  .community-banner { aspect-ratio: 16/7; }
  .community-banner-text { padding: 20px; }
  .community-banner-text h2 { font-size: 1.2rem; }
  .hero-actions { flex-direction: column; align-items: flex-start; }
  .social-share { flex-direction: column; align-items: center; }
  .search-bar-wrap { margin-top: 104px !important; }
}

@media (max-width: 480px) {
  .section { padding: 48px 0; }
  .cat-grid { grid-template-columns: repeat(2, 1fr); }
  .partners-grid { grid-template-columns: repeat(2, 1fr); }
  .hero-stats { gap: 16px; }
  .hero h1 { font-size: 2rem; }
  .ns-s127i5ng { display: none; }
  .site-header { top: 0; }
  .search-bar-wrap { margin-top: 68px !important; }
}

/* ===== 图片加载动画 ===== */
img { transition: opacity 0.3s ease; }
img.loaded { opacity: 1; }