/* ========================================
   糖心,视频 - 主样式文件
   域名: zedwj0.cn
   ======================================== */

/* CSS变量 - 原创配色方案 */
:root {
  --primary: #1a3a5c;
  --primary-light: #2563a8;
  --accent: #e85d26;
  --accent-light: #f07d4a;
  --bg-dark: #0d1b2a;
  --bg-mid: #112233;
  --bg-light: #f5f7fa;
  --text-main: #1a1a2e;
  --text-sub: #4a5568;
  --text-light: #718096;
  --white: #ffffff;
  --border: #e2e8f0;
  --card-bg: #ffffff;
  --shadow: 0 4px 20px rgba(26,58,92,0.10);
  --shadow-hover: 0 8px 32px rgba(26,58,92,0.18);
  --radius: 12px;
  --radius-sm: 8px;
  --transition: all 0.3s cubic-bezier(0.4,0,0.2,1);
}

/* 重置与基础 */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; font-size: 16px; }
body {
  font-family: 'PingFang SC', 'Microsoft YaHei', 'Helvetica Neue', Arial, sans-serif;
  color: var(--text-main);
  background: var(--bg-light);
  line-height: 1.7;
  overflow-x: hidden;
}
a { color: inherit; text-decoration: none; transition: var(--transition); }
img { max-width: 100%; height: auto; display: block; }
ul, ol { list-style: none; }

/* ========== 顶部公告栏 ========== */
.top-bar {
  background: linear-gradient(90deg, var(--primary) 0%, var(--primary-light) 100%);
  color: rgba(255,255,255,0.9);
  font-size: 13px;
  padding: 6px 0;
  text-align: center;
  letter-spacing: 0.5px;
}
.top-bar a { color: var(--accent-light); }

/* ========== 头部导航 ========== */
.site-header {
  background: var(--white);
  box-shadow: 0 2px 16px rgba(26,58,92,0.08);
  position: sticky;
  top: 0;
  z-index: 1000;
}
.header-inner {
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 24px;
  display: flex;
  align-items: center;
  height: 68px;
  gap: 32px;
}
.site-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-shrink: 0;
}
.site-logo img {
  width: 44px;
  height: 44px;
  object-fit: contain;
}
.site-logo .logo-text {
  font-size: 22px;
  font-weight: 800;
  color: var(--primary);
  letter-spacing: 1px;
}
.site-logo .logo-sub {
  font-size: 11px;
  color: var(--accent);
  display: block;
  line-height: 1;
  margin-top: 2px;
}
.main-nav {
  flex: 1;
  display: flex;
  align-items: center;
  gap: 4px;
}
.main-nav a {
  padding: 8px 14px;
  border-radius: var(--radius-sm);
  font-size: 15px;
  font-weight: 500;
  color: var(--text-main);
  white-space: nowrap;
  position: relative;
}
.main-nav a:hover, .main-nav a.active {
  color: var(--accent);
  background: rgba(232,93,38,0.07);
}
.main-nav a.active::after {
  content: '';
  position: absolute;
  bottom: 2px;
  left: 50%;
  transform: translateX(-50%);
  width: 20px;
  height: 2px;
  background: var(--accent);
  border-radius: 2px;
}
.header-actions {
  display: flex;
  align-items: center;
  gap: 12px;
  flex-shrink: 0;
}
.btn-join {
  background: linear-gradient(135deg, var(--accent) 0%, var(--accent-light) 100%);
  color: var(--white) !important;
  padding: 8px 20px;
  border-radius: 20px;
  font-size: 14px;
  font-weight: 600;
  box-shadow: 0 2px 8px rgba(232,93,38,0.3);
}
.btn-join:hover {
  transform: translateY(-1px);
  box-shadow: 0 4px 16px rgba(232,93,38,0.4);
}
.hamburger {
  display: none;
  flex-direction: column;
  gap: 5px;
  cursor: pointer;
  padding: 4px;
}
.hamburger span {
  width: 24px;
  height: 2px;
  background: var(--primary);
  border-radius: 2px;
  transition: var(--transition);
}

/* ========== 搜索框 ========== */
.search-bar-wrap {
  background: linear-gradient(135deg, #f0f4f8 0%, #e8edf5 100%);
  border-bottom: 1px solid var(--border);
  padding: 12px 0;
}
.search-bar-inner {
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 24px;
  display: flex;
  align-items: center;
  gap: 12px;
}
.search-form {
  display: flex;
  flex: 1;
  max-width: 600px;
  background: var(--white);
  border-radius: 24px;
  border: 2px solid var(--border);
  overflow: hidden;
  transition: var(--transition);
}
.search-form:focus-within {
  border-color: var(--primary-light);
  box-shadow: 0 0 0 3px rgba(37,99,168,0.1);
}
.search-form input {
  flex: 1;
  border: none;
  outline: none;
  padding: 10px 18px;
  font-size: 14px;
  background: transparent;
  color: var(--text-main);
}
.search-form button {
  background: linear-gradient(135deg, var(--primary) 0%, var(--primary-light) 100%);
  color: var(--white);
  border: none;
  padding: 10px 22px;
  cursor: pointer;
  font-size: 14px;
  font-weight: 600;
  transition: var(--transition);
}
.search-form button:hover { opacity: 0.9; }
.search-hot-tags {
  display: flex;
  align-items: center;
  gap: 8px;
  flex-wrap: wrap;
  font-size: 13px;
  color: var(--text-sub);
}
.search-hot-tags span { color: var(--text-light); }
.search-hot-tags a {
  color: var(--primary-light);
  background: rgba(37,99,168,0.08);
  padding: 3px 10px;
  border-radius: 12px;
  font-size: 12px;
}
.search-hot-tags a:hover { background: rgba(37,99,168,0.15); }

/* ========== 面包屑 ========== */
.breadcrumb {
  background: var(--white);
  border-bottom: 1px solid var(--border);
  padding: 10px 0;
  font-size: 13px;
  color: var(--text-light);
}
.breadcrumb-inner {
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 24px;
  display: flex;
  align-items: center;
  gap: 6px;
}
.breadcrumb a { color: var(--primary-light); }
.breadcrumb a:hover { color: var(--accent); }
.breadcrumb .sep { color: var(--border); }

/* ========== Hero Banner ========== */
.hero-banner {
  position: relative;
  height: 520px;
  overflow: hidden;
  background: var(--bg-dark);
}
.hero-slides { height: 100%; }
.hero-slide {
  position: absolute;
  inset: 0;
  opacity: 0;
  transition: opacity 0.8s ease;
}
.hero-slide.active { opacity: 1; }
.hero-slide img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center top;
}
.hero-overlay {
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, rgba(13,27,42,0.75) 0%, rgba(13,27,42,0.3) 60%, transparent 100%);
}
.hero-content {
  position: absolute;
  left: 0;
  top: 50%;
  transform: translateY(-50%);
  max-width: 1280px;
  width: 100%;
  margin: 0 auto;
  padding: 0 24px;
  right: 0;
}
.hero-tag {
  display: inline-block;
  background: var(--accent);
  color: var(--white);
  font-size: 12px;
  font-weight: 700;
  padding: 4px 12px;
  border-radius: 4px;
  letter-spacing: 1px;
  margin-bottom: 16px;
  text-transform: uppercase;
}
.hero-content h1 {
  font-size: 48px;
  font-weight: 900;
  color: var(--white);
  line-height: 1.2;
  margin-bottom: 16px;
  text-shadow: 0 2px 16px rgba(0,0,0,0.3);
}
.hero-content p {
  font-size: 18px;
  color: rgba(255,255,255,0.85);
  margin-bottom: 28px;
  max-width: 520px;
}
.hero-btns { display: flex; gap: 14px; flex-wrap: wrap; }
.btn-primary {
  background: linear-gradient(135deg, var(--accent) 0%, var(--accent-light) 100%);
  color: var(--white);
  padding: 14px 32px;
  border-radius: 28px;
  font-size: 16px;
  font-weight: 700;
  box-shadow: 0 4px 20px rgba(232,93,38,0.4);
  display: inline-flex;
  align-items: center;
  gap: 8px;
}
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 8px 28px rgba(232,93,38,0.5); color: var(--white); }
.btn-outline {
  border: 2px solid rgba(255,255,255,0.7);
  color: var(--white);
  padding: 12px 28px;
  border-radius: 28px;
  font-size: 16px;
  font-weight: 600;
  backdrop-filter: blur(4px);
  background: rgba(255,255,255,0.1);
}
.btn-outline:hover { background: rgba(255,255,255,0.2); border-color: var(--white); }
.hero-dots {
  position: absolute;
  bottom: 24px;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  gap: 8px;
}
.hero-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: rgba(255,255,255,0.4);
  cursor: pointer;
  transition: var(--transition);
}
.hero-dot.active { background: var(--white); width: 24px; border-radius: 4px; }

/* ========== 统计数字条 ========== */
.stats-bar {
  background: linear-gradient(135deg, var(--primary) 0%, var(--primary-light) 100%);
  padding: 20px 0;
}
.stats-inner {
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 24px;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 0;
}
.stat-item {
  text-align: center;
  padding: 8px 0;
  border-right: 1px solid rgba(255,255,255,0.15);
}
.stat-item:last-child { border-right: none; }
.stat-num {
  font-size: 32px;
  font-weight: 900;
  color: var(--white);
  line-height: 1;
  margin-bottom: 4px;
}
.stat-num span { color: var(--accent-light); }
.stat-label { font-size: 13px; color: rgba(255,255,255,0.7); }

/* ========== 通用区块 ========== */
.section { padding: 60px 0; }
.section-alt { background: var(--white); }
.container {
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 24px;
}
.section-header {
  text-align: center;
  margin-bottom: 44px;
}
.section-tag {
  display: inline-block;
  background: rgba(232,93,38,0.1);
  color: var(--accent);
  font-size: 13px;
  font-weight: 700;
  padding: 4px 14px;
  border-radius: 12px;
  margin-bottom: 12px;
  letter-spacing: 1px;
}
.section-title {
  font-size: 32px;
  font-weight: 800;
  color: var(--primary);
  margin-bottom: 12px;
  line-height: 1.3;
}
.section-desc {
  font-size: 16px;
  color: var(--text-sub);
  max-width: 600px;
  margin: 0 auto;
}

/* ========== 视频卡片 ========== */
.video-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}
.video-card {
  background: var(--card-bg);
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: var(--shadow);
  transition: var(--transition);
  cursor: pointer;
}
.video-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-hover);
}
.video-thumb {
  position: relative;
  aspect-ratio: 16/9;
  overflow: hidden;
  background: var(--bg-dark);
}
.video-thumb img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.4s ease;
}
.video-card:hover .video-thumb img { transform: scale(1.05); }
.video-play-btn {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(0,0,0,0);
  transition: var(--transition);
  opacity: 0;
}
.video-card:hover .video-play-btn {
  opacity: 1;
  background: rgba(0,0,0,0.35);
}
.play-icon {
  width: 52px;
  height: 52px;
  background: rgba(255,255,255,0.92);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  transform: scale(0.8);
  transition: transform 0.3s ease;
}
.video-card:hover .play-icon { transform: scale(1); }
.play-icon::after {
  content: '';
  border-left: 18px solid var(--accent);
  border-top: 11px solid transparent;
  border-bottom: 11px solid transparent;
  margin-left: 4px;
}
.video-duration {
  position: absolute;
  bottom: 8px;
  right: 8px;
  background: rgba(0,0,0,0.7);
  color: var(--white);
  font-size: 12px;
  padding: 2px 6px;
  border-radius: 4px;
}
.video-live-badge {
  position: absolute;
  top: 8px;
  left: 8px;
  background: #e53e3e;
  color: var(--white);
  font-size: 11px;
  font-weight: 700;
  padding: 2px 8px;
  border-radius: 4px;
  letter-spacing: 0.5px;
  animation: pulse 2s infinite;
}
@keyframes pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.7; }
}
.video-info { padding: 14px; }
.video-title {
  font-size: 14px;
  font-weight: 600;
  color: var(--text-main);
  margin-bottom: 8px;
  line-height: 1.4;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}
.video-meta {
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 12px;
  color: var(--text-light);
}
.video-stats { display: flex; gap: 10px; }
.video-stats span { display: flex; align-items: center; gap: 3px; }

/* ========== 特色栏目 ========== */
.feature-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}
.feature-card {
  background: var(--card-bg);
  border-radius: var(--radius);
  padding: 28px 24px;
  box-shadow: var(--shadow);
  transition: var(--transition);
  border: 1px solid var(--border);
  position: relative;
  overflow: hidden;
}
.feature-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--primary) 0%, var(--accent) 100%);
}
.feature-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-hover); }
.feature-icon {
  width: 52px;
  height: 52px;
  background: linear-gradient(135deg, var(--primary) 0%, var(--primary-light) 100%);
  border-radius: 14px;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 18px;
  font-size: 24px;
}
.feature-card h3 {
  font-size: 18px;
  font-weight: 700;
  color: var(--primary);
  margin-bottom: 10px;
}
.feature-card p { font-size: 14px; color: var(--text-sub); line-height: 1.7; }

/* ========== 专家展示 ========== */
.expert-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
}
.expert-card {
  background: var(--card-bg);
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: var(--shadow);
  transition: var(--transition);
  text-align: center;
}
.expert-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-hover); }
.expert-avatar {
  position: relative;
  height: 200px;
  overflow: hidden;
}
.expert-avatar img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: top;
}
.expert-badge {
  position: absolute;
  bottom: 12px;
  left: 50%;
  transform: translateX(-50%);
  background: var(--accent);
  color: var(--white);
  font-size: 11px;
  font-weight: 700;
  padding: 3px 12px;
  border-radius: 12px;
  white-space: nowrap;
}
.expert-info { padding: 18px 16px; }
.expert-name {
  font-size: 16px;
  font-weight: 700;
  color: var(--primary);
  margin-bottom: 4px;
}
.expert-title {
  font-size: 13px;
  color: var(--accent);
  margin-bottom: 10px;
}
.expert-desc {
  font-size: 13px;
  color: var(--text-sub);
  line-height: 1.6;
  margin-bottom: 14px;
}
.expert-btns { display: flex; gap: 8px; justify-content: center; }
.btn-sm {
  font-size: 12px;
  padding: 6px 14px;
  border-radius: 16px;
  font-weight: 600;
  border: 1.5px solid var(--primary-light);
  color: var(--primary-light);
  transition: var(--transition);
}
.btn-sm:hover { background: var(--primary-light); color: var(--white); }
.btn-sm.filled { background: var(--primary-light); color: var(--white); border-color: var(--primary-light); }
.btn-sm.filled:hover { background: var(--primary); border-color: var(--primary); }

/* ========== 图片展示墙 ========== */
.photo-wall {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
}
.photo-item {
  position: relative;
  border-radius: var(--radius);
  overflow: hidden;
  aspect-ratio: 3/4;
  cursor: pointer;
}
.photo-item img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.4s ease;
}
.photo-item:hover img { transform: scale(1.06); }
.photo-overlay {
  position: absolute;
  inset: 0;
  background: linear-gradient(to top, rgba(13,27,42,0.7) 0%, transparent 50%);
  opacity: 0;
  transition: var(--transition);
  display: flex;
  align-items: flex-end;
  padding: 16px;
}
.photo-item:hover .photo-overlay { opacity: 1; }
.photo-overlay span {
  color: var(--white);
  font-size: 14px;
  font-weight: 600;
}

/* ========== AI功能卡片 ========== */
.ai-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}
.ai-card {
  background: linear-gradient(135deg, var(--bg-dark) 0%, var(--bg-mid) 100%);
  border-radius: var(--radius);
  padding: 28px;
  color: var(--white);
  position: relative;
  overflow: hidden;
  transition: var(--transition);
}
.ai-card::after {
  content: '';
  position: absolute;
  top: -30%;
  right: -10%;
  width: 180px;
  height: 180px;
  background: radial-gradient(circle, rgba(232,93,38,0.15) 0%, transparent 70%);
  pointer-events: none;
}
.ai-card:hover { transform: translateY(-4px); }
.ai-icon { font-size: 36px; margin-bottom: 16px; }
.ai-card h3 { font-size: 18px; font-weight: 700; margin-bottom: 10px; color: var(--white); }
.ai-card p { font-size: 14px; color: rgba(255,255,255,0.7); line-height: 1.7; }
.ai-tag {
  display: inline-block;
  background: rgba(232,93,38,0.2);
  color: var(--accent-light);
  font-size: 11px;
  padding: 3px 10px;
  border-radius: 8px;
  margin-top: 14px;
  font-weight: 600;
}

/* ========== 社区功能 ========== */
.community-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 24px;
}
.community-card {
  background: var(--card-bg);
  border-radius: var(--radius);
  padding: 24px;
  box-shadow: var(--shadow);
  display: flex;
  gap: 18px;
  align-items: flex-start;
  transition: var(--transition);
  border: 1px solid var(--border);
}
.community-card:hover { transform: translateY(-3px); box-shadow: var(--shadow-hover); }
.community-icon {
  width: 48px;
  height: 48px;
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 22px;
  flex-shrink: 0;
}
.community-card h3 { font-size: 16px; font-weight: 700; color: var(--primary); margin-bottom: 6px; }
.community-card p { font-size: 13px; color: var(--text-sub); line-height: 1.6; }

/* ========== 合作品牌 ========== */
.partner-logos {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  justify-content: center;
  align-items: center;
}
.partner-logo {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 14px 28px;
  font-size: 14px;
  font-weight: 700;
  color: var(--text-sub);
  transition: var(--transition);
  min-width: 120px;
  text-align: center;
}
.partner-logo:hover { border-color: var(--primary-light); color: var(--primary); box-shadow: var(--shadow); }

/* ========== How-To 加入 ========== */
.join-steps {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
  position: relative;
}
.join-steps::before {
  content: '';
  position: absolute;
  top: 28px;
  left: 12.5%;
  right: 12.5%;
  height: 2px;
  background: linear-gradient(90deg, var(--primary-light) 0%, var(--accent) 100%);
  z-index: 0;
}
.join-step {
  text-align: center;
  position: relative;
  z-index: 1;
}
.step-num {
  width: 56px;
  height: 56px;
  background: linear-gradient(135deg, var(--primary) 0%, var(--primary-light) 100%);
  color: var(--white);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 20px;
  font-weight: 800;
  margin: 0 auto 16px;
  box-shadow: 0 4px 12px rgba(26,58,92,0.3);
}
.join-step h4 { font-size: 15px; font-weight: 700; color: var(--primary); margin-bottom: 8px; }
.join-step p { font-size: 13px; color: var(--text-sub); }

/* ========== FAQ ========== */
.faq-list { max-width: 800px; margin: 0 auto; }
.faq-item {
  background: var(--card-bg);
  border-radius: var(--radius);
  margin-bottom: 12px;
  box-shadow: var(--shadow);
  overflow: hidden;
  border: 1px solid var(--border);
}
.faq-question {
  padding: 18px 22px;
  font-size: 15px;
  font-weight: 600;
  color: var(--primary);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  transition: var(--transition);
}
.faq-question:hover { background: rgba(37,99,168,0.04); }
.faq-question .faq-icon {
  width: 24px;
  height: 24px;
  border-radius: 50%;
  background: rgba(37,99,168,0.1);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 16px;
  flex-shrink: 0;
  transition: var(--transition);
}
.faq-item.open .faq-icon { transform: rotate(45deg); background: var(--accent); color: var(--white); }
.faq-answer {
  padding: 0 22px;
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.35s ease, padding 0.35s ease;
  font-size: 14px;
  color: var(--text-sub);
  line-height: 1.8;
}
.faq-item.open .faq-answer { max-height: 300px; padding: 0 22px 18px; }

/* ========== 用户评价 ========== */
.reviews-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}
.review-card {
  background: var(--card-bg);
  border-radius: var(--radius);
  padding: 22px;
  box-shadow: var(--shadow);
  border: 1px solid var(--border);
  transition: var(--transition);
}
.review-card:hover { transform: translateY(-3px); box-shadow: var(--shadow-hover); }
.review-stars { color: #f6ad55; font-size: 16px; margin-bottom: 12px; letter-spacing: 2px; }
.review-text {
  font-size: 14px;
  color: var(--text-sub);
  line-height: 1.7;
  margin-bottom: 16px;
  font-style: italic;
}
.review-user { display: flex; align-items: center; gap: 10px; }
.review-avatar {
  width: 36px;
  height: 36px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--primary) 0%, var(--accent) 100%);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--white);
  font-size: 14px;
  font-weight: 700;
  flex-shrink: 0;
}
.review-name { font-size: 14px; font-weight: 600; color: var(--text-main); }
.review-date { font-size: 12px; color: var(--text-light); }

/* ========== 联系我们 ========== */
.contact-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 32px;
  align-items: start;
}
.contact-info h3 { font-size: 22px; font-weight: 700; color: var(--primary); margin-bottom: 20px; }
.contact-item {
  display: flex;
  gap: 14px;
  margin-bottom: 18px;
  align-items: flex-start;
}
.contact-icon {
  width: 40px;
  height: 40px;
  background: linear-gradient(135deg, var(--primary) 0%, var(--primary-light) 100%);
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 18px;
  flex-shrink: 0;
}
.contact-item h4 { font-size: 14px; font-weight: 600; color: var(--primary); margin-bottom: 3px; }
.contact-item p { font-size: 13px; color: var(--text-sub); }
.qr-codes { display: flex; gap: 20px; }
.qr-item { text-align: center; }
.qr-item img { width: 120px; height: 120px; object-fit: cover; border-radius: var(--radius-sm); border: 2px solid var(--border); }
.qr-item p { font-size: 12px; color: var(--text-sub); margin-top: 6px; }

/* ========== 分享按钮 ========== */
.share-bar {
  display: flex;
  align-items: center;
  gap: 12px;
  flex-wrap: wrap;
}
.share-label { font-size: 14px; color: var(--text-sub); font-weight: 600; }
.share-btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 8px 16px;
  border-radius: 20px;
  font-size: 13px;
  font-weight: 600;
  transition: var(--transition);
  cursor: pointer;
}
.share-wechat { background: #07c160; color: var(--white); }
.share-weibo { background: #e6162d; color: var(--white); }
.share-douyin { background: #161823; color: var(--white); }
.share-bilibili { background: #00a1d6; color: var(--white); }
.share-btn:hover { transform: translateY(-2px); opacity: 0.9; }

/* ========== 页脚 ========== */
.site-footer {
  background: var(--bg-dark);
  color: rgba(255,255,255,0.8);
  padding: 60px 0 0;
}
.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 40px;
  padding-bottom: 40px;
  border-bottom: 1px solid rgba(255,255,255,0.1);
}
.footer-brand .logo-wrap {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 16px;
}
.footer-brand img { width: 40px; height: 40px; object-fit: contain; }
.footer-brand .brand-name { font-size: 20px; font-weight: 800; color: var(--white); }
.footer-brand p { font-size: 14px; color: rgba(255,255,255,0.6); line-height: 1.7; margin-bottom: 20px; }
.footer-qr { display: flex; gap: 16px; }
.footer-qr-item { text-align: center; }
.footer-qr-item img { width: 80px; height: 80px; object-fit: cover; border-radius: 8px; border: 1px solid rgba(255,255,255,0.2); }
.footer-qr-item p { font-size: 11px; color: rgba(255,255,255,0.5); margin-top: 4px; }
.footer-col h4 { font-size: 15px; font-weight: 700; color: var(--white); margin-bottom: 16px; }
.footer-col ul li { margin-bottom: 10px; }
.footer-col ul li a { font-size: 13px; color: rgba(255,255,255,0.6); transition: var(--transition); }
.footer-col ul li a:hover { color: var(--accent-light); padding-left: 4px; }
.footer-bottom {
  padding: 20px 0;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 12px;
}
.footer-bottom p { font-size: 13px; color: rgba(255,255,255,0.4); }
.footer-links { display: flex; gap: 16px; }
.footer-links a { font-size: 13px; color: rgba(255,255,255,0.4); }
.footer-links a:hover { color: rgba(255,255,255,0.7); }

/* ========== 内页通用 ========== */
.page-hero {
  background: linear-gradient(135deg, var(--primary) 0%, var(--bg-dark) 100%);
  padding: 60px 0;
  text-align: center;
  color: var(--white);
}
.page-hero h1 { font-size: 38px; font-weight: 800; margin-bottom: 12px; }
.page-hero p { font-size: 16px; color: rgba(255,255,255,0.75); max-width: 600px; margin: 0 auto; }

/* ========== 加载更多 ========== */
.load-more-wrap { text-align: center; margin-top: 36px; }
.btn-load-more {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: var(--white);
  border: 2px solid var(--primary-light);
  color: var(--primary-light);
  padding: 12px 32px;
  border-radius: 24px;
  font-size: 15px;
  font-weight: 600;
  cursor: pointer;
  transition: var(--transition);
}
.btn-load-more:hover { background: var(--primary-light); color: var(--white); }

/* ========== 移动端菜单 ========== */
.mobile-menu {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,0.5);
  z-index: 2000;
}
.mobile-menu.open { display: block; }
.mobile-menu-inner {
  position: absolute;
  top: 0;
  right: 0;
  width: 280px;
  height: 100%;
  background: var(--white);
  padding: 24px;
  overflow-y: auto;
  transform: translateX(100%);
  transition: transform 0.3s ease;
}
.mobile-menu.open .mobile-menu-inner { transform: translateX(0); }
.mobile-menu-close {
  display: flex;
  justify-content: flex-end;
  margin-bottom: 20px;
  cursor: pointer;
  font-size: 24px;
  color: var(--text-sub);
}
.mobile-menu-inner a {
  display: block;
  padding: 12px 0;
  font-size: 16px;
  font-weight: 500;
  color: var(--text-main);
  border-bottom: 1px solid var(--border);
}
.mobile-menu-inner a:hover { color: var(--accent); }

/* ========== 响应式 ========== */
@media (max-width: 1100px) {
  .video-grid { grid-template-columns: repeat(3, 1fr); }
  .expert-grid { grid-template-columns: repeat(2, 1fr); }
  .reviews-grid { grid-template-columns: repeat(2, 1fr); }
  .footer-grid { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 768px) {
  .main-nav, .header-actions .btn-join { display: none; }
  .hamburger { display: flex; }
  .hero-banner { height: 320px; }
  .hero-content h1 { font-size: 28px; }
  .hero-content p { font-size: 14px; }
  .stats-inner { grid-template-columns: repeat(2, 1fr); }
  .video-grid { grid-template-columns: repeat(2, 1fr); }
  .feature-grid { grid-template-columns: 1fr; }
  .ai-grid { grid-template-columns: 1fr; }
  .community-grid { grid-template-columns: 1fr; }
  .expert-grid { grid-template-columns: repeat(2, 1fr); }
  .join-steps { grid-template-columns: repeat(2, 1fr); }
  .join-steps::before { display: none; }
  .reviews-grid { grid-template-columns: 1fr; }
  .contact-grid { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr; }
  .section-title { font-size: 24px; }
  .photo-wall { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 480px) {
  .video-grid { grid-template-columns: 1fr; }
  .expert-grid { grid-template-columns: 1fr; }
  .stats-inner { grid-template-columns: repeat(2, 1fr); }
  .hero-btns { flex-direction: column; }
  .search-hot-tags { display: none; }
}

/* ========== 辅助类 ========== */
.text-center { text-align: center; }
.mt-8 { margin-top: 8px; }
.mt-16 { margin-top: 16px; }
.mt-24 { margin-top: 24px; }
.mb-8 { margin-bottom: 8px; }
.mb-16 { margin-bottom: 16px; }
.flex { display: flex; }
.flex-center { display: flex; align-items: center; justify-content: center; }
.gap-8 { gap: 8px; }
.gap-16 { gap: 16px; }
.hidden { display: none; }

/* ========== 懒加载占位 ========== */
img[data-src] {
  background: linear-gradient(90deg, #f0f4f8 25%, #e8edf5 50%, #f0f4f8 75%);
  background-size: 200% 100%;
  animation: shimmer 1.5s infinite;
}
@keyframes shimmer {
  0% { background-position: 200% 0; }
  100% { background-position: -200% 0; }
}