/* ================================================
   海角社区 - 主样式文件
   网站: 24media.cn
   版本: 1.0.0
   ================================================ */

/* ---- CSS 变量 ---- */
:root {
  --primary: #0a6e8a;
  --primary-dark: #074f65;
  --primary-light: #12a0c8;
  --accent: #f0a500;
  --accent-dark: #c88800;
  --teal: #00c9b1;
  --teal-dark: #009e8c;
  --dark: #0d1b2a;
  --dark2: #162535;
  --dark3: #1e3448;
  --mid: #2c4a62;
  --light: #e8f4f8;
  --lighter: #f4fafc;
  --white: #ffffff;
  --text: #1a2e3d;
  --text-muted: #5a7a8e;
  --border: #c8dde8;
  --shadow: 0 4px 20px rgba(10,110,138,0.12);
  --shadow-lg: 0 8px 40px rgba(10,110,138,0.18);
  --radius: 10px;
  --radius-lg: 18px;
  --transition: all 0.3s cubic-bezier(0.4,0,0.2,1);
  --font-main: 'PingFang SC', 'Microsoft YaHei', '微软雅黑', 'Helvetica Neue', Arial, sans-serif;
}

/* ---- 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: var(--font-main);
  background: var(--lighter);
  color: var(--text);
  line-height: 1.7;
  overflow-x: hidden;
}
a { color: var(--primary); text-decoration: none; transition: var(--transition); }
a:hover { color: var(--accent); }
img { max-width: 100%; height: auto; display: block; }
ul, ol { list-style: none; }
button { cursor: pointer; font-family: var(--font-main); }
input, textarea, select { font-family: var(--font-main); }

/* ---- 滚动条 ---- */
::-webkit-scrollbar { width: 6px; }
::-webkit-scrollbar-track { background: var(--light); }
::-webkit-scrollbar-thumb { background: var(--primary-light); border-radius: 3px; }

/* ================================================
   顶部公告条
   ================================================ */
.top-bar {
  background: linear-gradient(90deg, var(--dark) 0%, var(--dark3) 100%);
  color: rgba(255,255,255,0.85);
  font-size: 13px;
  padding: 7px 0;
  border-bottom: 1px solid rgba(255,255,255,0.08);
}
.top-bar .container { display: flex; justify-content: space-between; align-items: center; }
.top-bar-left { display: flex; gap: 20px; align-items: center; }
.top-bar-left span { display: flex; align-items: center; gap: 5px; }
.top-bar-right { display: flex; gap: 16px; align-items: center; }
.top-bar-right a { color: rgba(255,255,255,0.75); font-size: 12px; }
.top-bar-right a:hover { color: var(--accent); }
.top-bar .badge {
  background: var(--accent);
  color: var(--dark);
  font-size: 11px;
  font-weight: 700;
  padding: 1px 7px;
  border-radius: 20px;
  animation: pulse 2s infinite;
}
@keyframes pulse { 0%,100%{opacity:1} 50%{opacity:0.7} }

/* ================================================
   头部导航
   ================================================ */
.site-header {
  background: var(--white);
  box-shadow: 0 2px 20px rgba(10,110,138,0.1);
  position: sticky;
  top: 0;
  z-index: 1000;
}
.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 12px 0;
  gap: 20px;
}
.site-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-shrink: 0;
}
.site-logo img.logo-img {
  height: 46px;
  width: auto;
}
.logo-text { display: flex; flex-direction: column; line-height: 1.2; }
.logo-name {
  font-size: 22px;
  font-weight: 800;
  background: linear-gradient(135deg, var(--primary) 0%, var(--teal) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  letter-spacing: 1px;
}
.logo-slogan { font-size: 11px; color: var(--text-muted); letter-spacing: 0.5px; }

/* 主导航 */
.main-nav { display: flex; align-items: center; gap: 2px; }
.main-nav > li { position: relative; }
.main-nav > li > a {
  display: flex;
  align-items: center;
  gap: 4px;
  padding: 8px 14px;
  font-size: 14px;
  font-weight: 600;
  color: var(--text);
  border-radius: var(--radius);
  transition: var(--transition);
  white-space: nowrap;
}
.main-nav > li > a:hover,
.main-nav > li.active > a {
  color: var(--primary);
  background: var(--light);
}
.main-nav > li > a .nav-arrow {
  font-size: 10px;
  transition: transform 0.3s;
}
.main-nav > li:hover > a .nav-arrow { transform: rotate(180deg); }

/* 下拉菜单 */
.dropdown {
  position: absolute;
  top: calc(100% + 8px);
  left: 0;
  background: var(--white);
  border-radius: var(--radius);
  box-shadow: var(--shadow-lg);
  border: 1px solid var(--border);
  min-width: 160px;
  opacity: 0;
  visibility: hidden;
  transform: translateY(-8px);
  transition: var(--transition);
  z-index: 100;
}
.main-nav > li:hover .dropdown {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}
.dropdown a {
  display: block;
  padding: 9px 16px;
  font-size: 13px;
  color: var(--text);
  border-bottom: 1px solid var(--light);
  transition: var(--transition);
}
.dropdown a:last-child { border-bottom: none; }
.dropdown a:hover { background: var(--light); color: var(--primary); padding-left: 22px; }

/* 头部右侧 */
.header-right { display: flex; align-items: center; gap: 10px; }
.btn-login {
  padding: 7px 18px;
  border: 1.5px solid var(--primary);
  color: var(--primary);
  border-radius: 20px;
  font-size: 13px;
  font-weight: 600;
  transition: var(--transition);
}
.btn-login:hover { background: var(--primary); color: var(--white); }
.btn-join {
  padding: 7px 18px;
  background: linear-gradient(135deg, var(--primary) 0%, var(--teal) 100%);
  color: var(--white);
  border-radius: 20px;
  font-size: 13px;
  font-weight: 700;
  border: none;
  box-shadow: 0 3px 12px rgba(10,110,138,0.3);
  transition: var(--transition);
}
.btn-join:hover { transform: translateY(-1px); box-shadow: 0 5px 18px rgba(10,110,138,0.4); }

/* 汉堡菜单 */
.hamburger { display: none; flex-direction: column; gap: 5px; cursor: pointer; padding: 5px; }
.hamburger span { display: block; width: 24px; height: 2px; background: var(--text); border-radius: 2px; transition: var(--transition); }

/* ================================================
   搜索框
   ================================================ */
.search-bar-wrap {
  background: linear-gradient(135deg, var(--primary-dark) 0%, var(--dark3) 100%);
  padding: 14px 0;
  border-bottom: 3px solid var(--teal);
}
.search-form {
  display: flex;
  max-width: 680px;
  margin: 0 auto;
  background: var(--white);
  border-radius: 30px;
  overflow: hidden;
  box-shadow: 0 4px 20px rgba(0,0,0,0.2);
}
.search-form select {
  padding: 0 14px;
  border: none;
  background: var(--light);
  color: var(--text);
  font-size: 13px;
  font-weight: 600;
  border-right: 1px solid var(--border);
  outline: none;
  cursor: pointer;
}
.search-form input {
  flex: 1;
  padding: 12px 18px;
  border: none;
  font-size: 14px;
  color: var(--text);
  outline: none;
}
.search-form input::placeholder { color: var(--text-muted); }
.search-btn {
  padding: 0 24px;
  background: linear-gradient(135deg, var(--primary) 0%, var(--teal) 100%);
  color: var(--white);
  border: none;
  font-size: 14px;
  font-weight: 700;
  cursor: pointer;
  transition: var(--transition);
}
.search-btn:hover { background: linear-gradient(135deg, var(--teal) 0%, var(--primary) 100%); }
.search-tags {
  display: flex;
  justify-content: center;
  gap: 10px;
  margin-top: 10px;
  flex-wrap: wrap;
}
.search-tags span { color: rgba(255,255,255,0.6); font-size: 12px; }
.search-tags a {
  color: rgba(255,255,255,0.85);
  font-size: 12px;
  padding: 2px 10px;
  border: 1px solid rgba(255,255,255,0.25);
  border-radius: 12px;
  transition: var(--transition);
}
.search-tags a:hover { background: rgba(255,255,255,0.15); color: var(--white); }

/* ================================================
   容器
   ================================================ */
.container { max-width: 1240px; margin: 0 auto; padding: 0 20px; }
.container-wide { max-width: 1440px; margin: 0 auto; padding: 0 20px; }

/* ================================================
   通用区块样式
   ================================================ */
.section { padding: 60px 0; }
.section-sm { padding: 40px 0; }
.section-lg { padding: 80px 0; }
.section-dark { background: var(--dark); color: var(--white); }
.section-dark2 { background: var(--dark2); color: var(--white); }
.section-teal { background: linear-gradient(135deg, var(--primary-dark) 0%, var(--dark3) 100%); color: var(--white); }
.section-light { background: var(--light); }
.section-white { background: var(--white); }

.section-header { text-align: center; margin-bottom: 44px; }
.section-header h2 {
  font-size: 30px;
  font-weight: 800;
  color: var(--dark);
  margin-bottom: 12px;
  position: relative;
  display: inline-block;
}
.section-header h2::after {
  content: '';
  display: block;
  width: 60px;
  height: 4px;
  background: linear-gradient(90deg, var(--primary), var(--teal));
  border-radius: 2px;
  margin: 10px auto 0;
}
.section-dark .section-header h2,
.section-dark2 .section-header h2,
.section-teal .section-header h2 { color: var(--white); }
.section-header p { color: var(--text-muted); font-size: 15px; max-width: 560px; margin: 0 auto; }
.section-dark .section-header p,
.section-teal .section-header p { color: rgba(255,255,255,0.7); }

/* ================================================
   Hero 横幅
   ================================================ */
.hero {
  position: relative;
  min-height: 520px;
  display: flex;
  align-items: center;
  overflow: hidden;
  background: var(--dark);
}
.hero-bg {
  position: absolute;
  inset: 0;
  background-image: url('../images/hero_banner.jpg');
  background-size: cover;
  background-position: center;
  opacity: 0.45;
  transform: scale(1.02);
  transition: transform 8s ease;
}
.hero:hover .hero-bg { transform: scale(1); }
.hero-overlay {
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, rgba(10,40,65,0.92) 0%, rgba(10,110,138,0.6) 60%, transparent 100%);
}
.hero-content {
  position: relative;
  z-index: 2;
  max-width: 640px;
  padding: 60px 0;
}
.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  background: rgba(240,165,0,0.2);
  border: 1px solid var(--accent);
  color: var(--accent);
  font-size: 12px;
  font-weight: 700;
  padding: 4px 14px;
  border-radius: 20px;
  margin-bottom: 18px;
  letter-spacing: 0.5px;
}
.hero h1 {
  font-size: 46px;
  font-weight: 900;
  color: var(--white);
  line-height: 1.2;
  margin-bottom: 18px;
  text-shadow: 0 2px 20px rgba(0,0,0,0.3);
}
.hero h1 span { color: var(--teal); }
.hero p {
  font-size: 17px;
  color: rgba(255,255,255,0.85);
  margin-bottom: 30px;
  line-height: 1.7;
}
.hero-btns { display: flex; gap: 14px; flex-wrap: wrap; }
.btn-hero-primary {
  padding: 13px 32px;
  background: linear-gradient(135deg, var(--primary) 0%, var(--teal) 100%);
  color: var(--white);
  border-radius: 30px;
  font-size: 15px;
  font-weight: 700;
  border: none;
  box-shadow: 0 5px 20px rgba(10,110,138,0.4);
  transition: var(--transition);
  display: inline-flex;
  align-items: center;
  gap: 8px;
}
.btn-hero-primary:hover { transform: translateY(-2px); box-shadow: 0 8px 28px rgba(10,110,138,0.5); color: var(--white); }
.btn-hero-secondary {
  padding: 13px 32px;
  background: rgba(255,255,255,0.12);
  color: var(--white);
  border-radius: 30px;
  font-size: 15px;
  font-weight: 600;
  border: 1.5px solid rgba(255,255,255,0.4);
  transition: var(--transition);
  display: inline-flex;
  align-items: center;
  gap: 8px;
  backdrop-filter: blur(4px);
}
.btn-hero-secondary:hover { background: rgba(255,255,255,0.22); color: var(--white); }
.hero-stats {
  display: flex;
  gap: 30px;
  margin-top: 36px;
  flex-wrap: wrap;
}
.hero-stat { text-align: center; }
.hero-stat .num {
  font-size: 26px;
  font-weight: 900;
  color: var(--teal);
  display: block;
  line-height: 1;
}
.hero-stat .label { font-size: 12px; color: rgba(255,255,255,0.65); margin-top: 4px; }

/* ================================================
   视频卡片
   ================================================ */
.video-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 20px;
}
.video-grid-4 { grid-template-columns: repeat(4, 1fr); }
.video-grid-3 { grid-template-columns: repeat(3, 1fr); }

.video-card {
  background: var(--white);
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow);
  transition: var(--transition);
  cursor: pointer;
}
.video-card:hover { transform: translateY(-5px); box-shadow: var(--shadow-lg); }
.video-thumb {
  position: relative;
  overflow: hidden;
  aspect-ratio: 16/9;
  background: var(--dark3);
}
.video-thumb img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.5s ease;
}
.video-card:hover .video-thumb img { transform: scale(1.06); }
.video-play-btn {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(0,0,0,0);
  transition: var(--transition);
}
.video-card:hover .video-play-btn { 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;
  opacity: 0;
  transform: scale(0.7);
  transition: var(--transition);
  box-shadow: 0 4px 20px rgba(0,0,0,0.3);
}
.video-card:hover .play-icon { opacity: 1; transform: scale(1); }
.play-icon::after {
  content: '';
  border-left: 18px solid var(--primary);
  border-top: 11px solid transparent;
  border-bottom: 11px solid transparent;
  margin-left: 4px;
}
.video-duration {
  position: absolute;
  bottom: 8px;
  right: 10px;
  background: rgba(0,0,0,0.75);
  color: var(--white);
  font-size: 11px;
  font-weight: 600;
  padding: 2px 7px;
  border-radius: 4px;
}
.video-quality {
  position: absolute;
  top: 8px;
  left: 10px;
  background: var(--accent);
  color: var(--dark);
  font-size: 10px;
  font-weight: 800;
  padding: 2px 7px;
  border-radius: 4px;
  letter-spacing: 0.5px;
}
.video-info { padding: 14px 16px; }
.video-info h3 {
  font-size: 14px;
  font-weight: 700;
  color: var(--text);
  margin-bottom: 8px;
  line-height: 1.4;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}
.video-meta {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 12px;
  color: var(--text-muted);
}
.video-meta-left { display: flex; gap: 12px; align-items: center; }
.video-meta .views::before { content: '▶ '; }
.video-meta .likes::before { content: '♥ '; color: #e74c3c; }
.video-meta .comments::before { content: '💬 '; }
.video-author { display: flex; align-items: center; gap: 6px; margin-top: 8px; }
.video-author-avatar {
  width: 22px;
  height: 22px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--primary), var(--teal));
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--white);
  font-size: 10px;
  font-weight: 700;
  flex-shrink: 0;
}
.video-author-name { font-size: 12px; color: var(--text-muted); }
.video-tag {
  display: inline-block;
  background: var(--light);
  color: var(--primary);
  font-size: 11px;
  padding: 2px 8px;
  border-radius: 10px;
  margin-top: 6px;
}

/* ================================================
   功能分类卡片
   ================================================ */
.category-grid {
  display: grid;
  grid-template-columns: repeat(6, 1fr);
  gap: 16px;
}
.category-card {
  background: var(--white);
  border-radius: var(--radius-lg);
  padding: 22px 14px;
  text-align: center;
  box-shadow: var(--shadow);
  transition: var(--transition);
  cursor: pointer;
  border: 2px solid transparent;
}
.category-card:hover {
  transform: translateY(-4px);
  border-color: var(--primary-light);
  box-shadow: var(--shadow-lg);
}
.category-icon {
  width: 56px;
  height: 56px;
  border-radius: 16px;
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 12px;
  font-size: 24px;
  transition: var(--transition);
}
.category-card:hover .category-icon { transform: scale(1.1) rotate(-5deg); }
.category-card h3 { font-size: 13px; font-weight: 700; color: var(--text); margin-bottom: 4px; }
.category-card p { font-size: 11px; color: var(--text-muted); }

/* ================================================
   专家卡片
   ================================================ */
.expert-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
}
.expert-card {
  background: var(--white);
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow);
  transition: var(--transition);
  text-align: center;
}
.expert-card:hover { transform: translateY(-5px); box-shadow: var(--shadow-lg); }
.expert-photo {
  position: relative;
  height: 200px;
  overflow: hidden;
  background: var(--light);
}
.expert-photo img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: top;
  transition: transform 0.5s;
}
.expert-card:hover .expert-photo img { transform: scale(1.05); }
.expert-badge {
  position: absolute;
  top: 12px;
  right: 12px;
  background: var(--accent);
  color: var(--dark);
  font-size: 11px;
  font-weight: 700;
  padding: 3px 10px;
  border-radius: 12px;
}
.expert-info { padding: 18px 16px; }
.expert-info h3 { font-size: 16px; font-weight: 800; color: var(--dark); margin-bottom: 4px; }
.expert-title { font-size: 13px; color: var(--primary); font-weight: 600; margin-bottom: 8px; }
.expert-desc { font-size: 12px; color: var(--text-muted); line-height: 1.6; margin-bottom: 12px; }
.expert-stats { display: flex; justify-content: center; gap: 20px; margin-bottom: 14px; }
.expert-stat { text-align: center; }
.expert-stat .n { font-size: 16px; font-weight: 800; color: var(--primary); display: block; }
.expert-stat .l { font-size: 11px; color: var(--text-muted); }
.expert-btns { display: flex; gap: 8px; justify-content: center; }
.btn-sm {
  padding: 6px 14px;
  border-radius: 16px;
  font-size: 12px;
  font-weight: 600;
  transition: var(--transition);
  border: none;
  cursor: pointer;
}
.btn-primary-sm {
  background: var(--primary);
  color: var(--white);
}
.btn-primary-sm:hover { background: var(--primary-dark); color: var(--white); }
.btn-outline-sm {
  background: transparent;
  color: var(--primary);
  border: 1.5px solid var(--primary);
}
.btn-outline-sm:hover { background: var(--primary); color: var(--white); }

/* ================================================
   合作品牌 Logo 墙
   ================================================ */
.partner-grid {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  justify-content: center;
  align-items: center;
}
.partner-item {
  background: var(--white);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 14px 28px;
  font-size: 14px;
  font-weight: 700;
  color: var(--text-muted);
  transition: var(--transition);
  display: flex;
  align-items: center;
  gap: 8px;
}
.partner-item:hover { border-color: var(--primary); color: var(--primary); transform: translateY(-2px); box-shadow: var(--shadow); }
.partner-item .p-icon { font-size: 20px; }

/* ================================================
   FAQ
   ================================================ */
.faq-list { max-width: 820px; margin: 0 auto; }
.faq-item {
  background: var(--white);
  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: 700;
  color: var(--text);
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
  transition: var(--transition);
  user-select: none;
}
.faq-question:hover { color: var(--primary); background: var(--lighter); }
.faq-question.active { color: var(--primary); background: var(--light); }
.faq-arrow {
  width: 24px;
  height: 24px;
  border-radius: 50%;
  background: var(--light);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 12px;
  transition: transform 0.3s;
  flex-shrink: 0;
}
.faq-question.active .faq-arrow { transform: rotate(180deg); background: var(--primary); color: var(--white); }
.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.4s ease;
}
.faq-answer-inner {
  padding: 0 22px 18px;
  font-size: 14px;
  color: var(--text-muted);
  line-height: 1.8;
  border-top: 1px solid var(--border);
  padding-top: 14px;
}

/* ================================================
   用户评论
   ================================================ */
.review-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}
.review-card {
  background: var(--white);
  border-radius: var(--radius-lg);
  padding: 22px;
  box-shadow: var(--shadow);
  transition: var(--transition);
  position: relative;
  border-top: 3px solid var(--primary-light);
}
.review-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-lg); }
.review-card::before {
  content: '"';
  position: absolute;
  top: 10px;
  right: 18px;
  font-size: 60px;
  color: var(--light);
  font-family: Georgia, serif;
  line-height: 1;
}
.review-stars { color: var(--accent); font-size: 14px; margin-bottom: 10px; letter-spacing: 2px; }
.review-text { font-size: 13px; color: var(--text); line-height: 1.7; margin-bottom: 14px; }
.review-user { display: flex; align-items: center; gap: 10px; }
.review-avatar {
  width: 38px;
  height: 38px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--primary), var(--teal));
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--white);
  font-size: 14px;
  font-weight: 700;
  flex-shrink: 0;
}
.review-user-info .name { font-size: 13px; font-weight: 700; color: var(--text); }
.review-user-info .date { font-size: 11px; color: var(--text-muted); }

/* ================================================
   联系我们
   ================================================ */
.contact-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 40px; align-items: start; }
.contact-info-card {
  background: var(--white);
  border-radius: var(--radius-lg);
  padding: 32px;
  box-shadow: var(--shadow);
}
.contact-info-card h3 { font-size: 20px; font-weight: 800; color: var(--dark); margin-bottom: 20px; }
.contact-item {
  display: flex;
  align-items: flex-start;
  gap: 14px;
  padding: 14px 0;
  border-bottom: 1px solid var(--light);
}
.contact-item:last-child { border-bottom: none; }
.contact-icon {
  width: 40px;
  height: 40px;
  border-radius: 10px;
  background: var(--light);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 18px;
  flex-shrink: 0;
}
.contact-item-text .label { font-size: 12px; color: var(--text-muted); margin-bottom: 2px; }
.contact-item-text .value { font-size: 14px; font-weight: 600; color: var(--text); }
.qr-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 20px; }
.qr-card {
  background: var(--white);
  border-radius: var(--radius-lg);
  padding: 20px;
  text-align: center;
  box-shadow: var(--shadow);
}
.qr-card img { width: 140px; height: 140px; margin: 0 auto 10px; border-radius: 8px; object-fit: cover; }
.qr-card p { font-size: 13px; color: var(--text-muted); }
.qr-card strong { display: block; font-size: 14px; color: var(--text); margin-bottom: 4px; }

/* ================================================
   社区入口
   ================================================ */
.community-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 20px; }
.community-card {
  background: linear-gradient(135deg, var(--dark3) 0%, var(--mid) 100%);
  border-radius: var(--radius-lg);
  padding: 28px 20px;
  text-align: center;
  transition: var(--transition);
  border: 1px solid rgba(255,255,255,0.08);
  cursor: pointer;
}
.community-card:hover { transform: translateY(-5px); box-shadow: 0 10px 30px rgba(0,0,0,0.3); border-color: var(--teal); }
.community-icon { font-size: 36px; margin-bottom: 14px; }
.community-card h3 { font-size: 15px; font-weight: 700; color: var(--white); margin-bottom: 6px; }
.community-card p { font-size: 12px; color: rgba(255,255,255,0.6); }
.community-online {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  background: rgba(0,201,177,0.15);
  color: var(--teal);
  font-size: 11px;
  padding: 3px 10px;
  border-radius: 12px;
  margin-top: 10px;
}
.community-online::before {
  content: '';
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--teal);
  animation: blink 1.5s infinite;
}
@keyframes blink { 0%,100%{opacity:1} 50%{opacity:0.3} }

/* ================================================
   How-To 加入指南
   ================================================ */
.howto-steps { display: grid; grid-template-columns: repeat(4, 1fr); gap: 24px; position: relative; }
.howto-steps::before {
  content: '';
  position: absolute;
  top: 36px;
  left: 12.5%;
  right: 12.5%;
  height: 2px;
  background: linear-gradient(90deg, var(--primary), var(--teal));
  z-index: 0;
}
.step-card {
  background: var(--white);
  border-radius: var(--radius-lg);
  padding: 28px 20px;
  text-align: center;
  box-shadow: var(--shadow);
  position: relative;
  z-index: 1;
  transition: var(--transition);
}
.step-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-lg); }
.step-num {
  width: 52px;
  height: 52px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--primary), var(--teal));
  color: var(--white);
  font-size: 20px;
  font-weight: 900;
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 16px;
  box-shadow: 0 4px 14px rgba(10,110,138,0.3);
}
.step-card h3 { font-size: 15px; font-weight: 700; color: var(--dark); margin-bottom: 8px; }
.step-card p { font-size: 13px; color: var(--text-muted); line-height: 1.6; }

/* ================================================
   AI 赋能区块
   ================================================ */
.ai-features { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.ai-card {
  background: var(--white);
  border-radius: var(--radius-lg);
  padding: 28px;
  box-shadow: var(--shadow);
  transition: var(--transition);
  border-left: 4px solid transparent;
}
.ai-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-lg); border-left-color: var(--teal); }
.ai-icon { font-size: 36px; margin-bottom: 14px; }
.ai-card h3 { font-size: 16px; font-weight: 800; color: var(--dark); margin-bottom: 8px; }
.ai-card p { font-size: 13px; color: var(--text-muted); line-height: 1.7; }
.ai-tag {
  display: inline-block;
  background: linear-gradient(135deg, var(--primary), var(--teal));
  color: var(--white);
  font-size: 11px;
  font-weight: 700;
  padding: 3px 10px;
  border-radius: 12px;
  margin-top: 12px;
}

/* ================================================
   社交分享
   ================================================ */
.share-bar {
  background: var(--white);
  border-radius: var(--radius);
  padding: 16px 24px;
  display: flex;
  align-items: center;
  gap: 14px;
  box-shadow: var(--shadow);
  flex-wrap: wrap;
}
.share-label { font-size: 13px; color: var(--text-muted); font-weight: 600; white-space: nowrap; }
.share-btns { display: flex; gap: 8px; flex-wrap: wrap; }
.share-btn {
  padding: 7px 16px;
  border-radius: 20px;
  font-size: 12px;
  font-weight: 700;
  border: none;
  cursor: pointer;
  transition: var(--transition);
  display: flex;
  align-items: center;
  gap: 5px;
}
.share-btn:hover { transform: translateY(-2px); }
.share-wechat { background: #07c160; color: #fff; }
.share-weibo { background: #e6162d; color: #fff; }
.share-douyin { background: #010101; color: #fff; }
.share-bilibili { background: #fb7299; color: #fff; }
.share-qq { background: #1e90ff; color: #fff; }

/* ================================================
   底部 Footer
   ================================================ */
.site-footer {
  background: var(--dark);
  color: rgba(255,255,255,0.75);
  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 { height: 40px; filter: brightness(1.2); }
.footer-brand .brand-name { font-size: 20px; font-weight: 800; color: var(--white); }
.footer-brand p { font-size: 13px; line-height: 1.8; color: rgba(255,255,255,0.6); margin-bottom: 20px; }
.footer-social { display: flex; gap: 10px; }
.social-icon {
  width: 36px;
  height: 36px;
  border-radius: 50%;
  background: rgba(255,255,255,0.1);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 14px;
  color: rgba(255,255,255,0.7);
  transition: var(--transition);
  cursor: pointer;
}
.social-icon:hover { background: var(--primary); color: var(--white); transform: translateY(-2px); }
.footer-col h4 { font-size: 14px; font-weight: 700; color: var(--white); margin-bottom: 16px; padding-bottom: 8px; border-bottom: 2px solid var(--primary); display: inline-block; }
.footer-links { display: flex; flex-direction: column; gap: 8px; }
.footer-links a { font-size: 13px; color: rgba(255,255,255,0.6); transition: var(--transition); }
.footer-links a:hover { color: var(--teal); padding-left: 4px; }
.footer-bottom {
  padding: 20px 0;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 10px;
  font-size: 12px;
  color: rgba(255,255,255,0.45);
}
.footer-bottom a { color: rgba(255,255,255,0.55); }
.footer-bottom a:hover { color: var(--teal); }
.footer-logo-bottom { display: flex; align-items: center; gap: 8px; }
.footer-logo-bottom img { height: 28px; filter: brightness(0.8); }

/* ================================================
   面包屑
   ================================================ */
.breadcrumb {
  background: var(--light);
  padding: 12px 0;
  border-bottom: 1px solid var(--border);
}
.breadcrumb ol { display: flex; align-items: center; gap: 6px; flex-wrap: wrap; }
.breadcrumb li { font-size: 13px; color: var(--text-muted); display: flex; align-items: center; gap: 6px; }
.breadcrumb li::after { content: '/'; color: var(--border); }
.breadcrumb li:last-child::after { display: none; }
.breadcrumb li:last-child { color: var(--text); font-weight: 600; }
.breadcrumb a { color: var(--primary); }
.breadcrumb a:hover { color: var(--accent); }

/* ================================================
   通用按钮
   ================================================ */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 10px 24px;
  border-radius: 24px;
  font-size: 14px;
  font-weight: 700;
  border: none;
  cursor: pointer;
  transition: var(--transition);
}
.btn-primary { background: linear-gradient(135deg, var(--primary), var(--teal)); color: var(--white); box-shadow: 0 3px 12px rgba(10,110,138,0.3); }
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 5px 18px rgba(10,110,138,0.4); color: var(--white); }
.btn-accent { background: var(--accent); color: var(--dark); }
.btn-accent:hover { background: var(--accent-dark); color: var(--dark); transform: translateY(-2px); }
.btn-outline { background: transparent; color: var(--primary); border: 2px solid var(--primary); }
.btn-outline:hover { background: var(--primary); color: var(--white); }
.btn-white { background: var(--white); color: var(--primary); }
.btn-white:hover { background: var(--light); color: var(--primary-dark); }
.btn-lg { padding: 14px 36px; font-size: 16px; }
.btn-block { width: 100%; justify-content: center; }

/* ================================================
   标签
   ================================================ */
.tag { display: inline-block; padding: 3px 10px; border-radius: 12px; font-size: 11px; font-weight: 600; }
.tag-primary { background: rgba(10,110,138,0.12); color: var(--primary); }
.tag-teal { background: rgba(0,201,177,0.12); color: var(--teal-dark); }
.tag-accent { background: rgba(240,165,0,0.15); color: var(--accent-dark); }
.tag-hot { background: #fff0f0; color: #e74c3c; }
.tag-new { background: #f0fff4; color: #27ae60; }

/* ================================================
   统计数字区块
   ================================================ */
.stats-row { display: grid; grid-template-columns: repeat(4, 1fr); gap: 24px; }
.stat-card {
  background: var(--white);
  border-radius: var(--radius-lg);
  padding: 28px;
  text-align: center;
  box-shadow: var(--shadow);
  border-top: 4px solid var(--primary-light);
  transition: var(--transition);
}
.stat-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-lg); }
.stat-card .big-num { font-size: 36px; font-weight: 900; color: var(--primary); display: block; line-height: 1; margin-bottom: 6px; }
.stat-card .stat-label { font-size: 13px; color: var(--text-muted); }
.stat-card .stat-icon { font-size: 28px; margin-bottom: 10px; }

/* ================================================
   公告/通知条
   ================================================ */
.notice-bar {
  background: linear-gradient(90deg, rgba(10,110,138,0.08), rgba(0,201,177,0.08));
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 12px 20px;
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 24px;
}
.notice-bar .notice-tag {
  background: var(--primary);
  color: var(--white);
  font-size: 11px;
  font-weight: 700;
  padding: 2px 10px;
  border-radius: 10px;
  white-space: nowrap;
}
.notice-bar p { font-size: 13px; color: var(--text); flex: 1; }
.notice-bar a { font-size: 13px; color: var(--primary); font-weight: 600; white-space: nowrap; }

/* ================================================
   内页 Banner
   ================================================ */
.page-banner {
  background: linear-gradient(135deg, var(--dark) 0%, var(--dark3) 100%);
  padding: 50px 0;
  position: relative;
  overflow: hidden;
}
.page-banner::before {
  content: '';
  position: absolute;
  top: -50%;
  right: -10%;
  width: 500px;
  height: 500px;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(10,110,138,0.3) 0%, transparent 70%);
}
.page-banner h1 { font-size: 34px; font-weight: 900; color: var(--white); margin-bottom: 10px; }
.page-banner p { font-size: 15px; color: rgba(255,255,255,0.7); }

/* ================================================
   响应式
   ================================================ */
@media (max-width: 1200px) {
  .video-grid-4 { grid-template-columns: repeat(3, 1fr); }
  .expert-grid { grid-template-columns: repeat(3, 1fr); }
  .category-grid { grid-template-columns: repeat(4, 1fr); }
  .review-grid { grid-template-columns: repeat(2, 1fr); }
  .footer-grid { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 992px) {
  .hero h1 { font-size: 34px; }
  .video-grid-4, .video-grid-3 { grid-template-columns: repeat(2, 1fr); }
  .expert-grid { grid-template-columns: repeat(2, 1fr); }
  .community-grid { grid-template-columns: repeat(2, 1fr); }
  .howto-steps { grid-template-columns: repeat(2, 1fr); }
  .howto-steps::before { display: none; }
  .ai-features { grid-template-columns: repeat(2, 1fr); }
  .stats-row { grid-template-columns: repeat(2, 1fr); }
  .contact-grid { grid-template-columns: 1fr; }
}
@media (max-width: 768px) {
  .top-bar { display: none; }
  .main-nav { display: none; position: fixed; top: 0; left: 0; right: 0; bottom: 0; background: var(--white); flex-direction: column; align-items: flex-start; padding: 80px 24px 24px; overflow-y: auto; z-index: 999; gap: 0; }
  .main-nav.open { display: flex; }
  .main-nav > li > a { padding: 14px 0; font-size: 16px; border-bottom: 1px solid var(--light); width: 100%; }
  .dropdown { position: static; opacity: 1; visibility: visible; transform: none; box-shadow: none; border: none; background: var(--lighter); padding-left: 16px; }
  .hamburger { display: flex; }
  .header-right .btn-login { display: none; }
  .hero h1 { font-size: 28px; }
  .hero-stats { gap: 16px; }
  .category-grid { grid-template-columns: repeat(3, 1fr); }
  .video-grid-4, .video-grid-3, .video-grid { grid-template-columns: repeat(2, 1fr); }
  .expert-grid { grid-template-columns: repeat(2, 1fr); }
  .review-grid { grid-template-columns: 1fr; }
  .community-grid { grid-template-columns: repeat(2, 1fr); }
  .howto-steps { grid-template-columns: 1fr; }
  .ai-features { grid-template-columns: 1fr; }
  .stats-row { grid-template-columns: repeat(2, 1fr); }
  .footer-grid { grid-template-columns: 1fr; }
  .footer-bottom { flex-direction: column; text-align: center; }
  .section { padding: 40px 0; }
  .section-header h2 { font-size: 24px; }
  .qr-grid { grid-template-columns: 1fr; }
  .search-form select { display: none; }
}
@media (max-width: 480px) {
  .category-grid { grid-template-columns: repeat(2, 1fr); }
  .video-grid-4, .video-grid-3, .video-grid { grid-template-columns: 1fr; }
  .expert-grid { grid-template-columns: 1fr; }
  .community-grid { grid-template-columns: 1fr; }
  .hero h1 { font-size: 24px; }
  .hero-btns { flex-direction: column; }
  .stats-row { grid-template-columns: 1fr 1fr; }
}

/* ================================================
   动画
   ================================================ */
@keyframes fadeInUp { from { opacity:0; transform:translateY(20px); } to { opacity:1; transform:translateY(0); } }
@keyframes fadeIn { from { opacity:0; } to { opacity:1; } }
.animate-fadeInUp { animation: fadeInUp 0.6s ease forwards; }
.animate-fadeIn { animation: fadeIn 0.5s ease forwards; }
.delay-1 { animation-delay: 0.1s; }
.delay-2 { animation-delay: 0.2s; }
.delay-3 { animation-delay: 0.3s; }
.delay-4 { animation-delay: 0.4s; }

/* ================================================
   工具类
   ================================================ */
.text-center { text-align: center; }
.text-right { text-align: right; }
.mt-8 { margin-top: 8px; }
.mt-16 { margin-top: 16px; }
.mt-24 { margin-top: 24px; }
.mt-32 { margin-top: 32px; }
.mb-8 { margin-bottom: 8px; }
.mb-16 { margin-bottom: 16px; }
.mb-24 { margin-bottom: 24px; }
.mb-32 { margin-bottom: 32px; }
.flex { display: flex; }
.flex-center { display: flex; align-items: center; justify-content: center; }
.flex-between { display: flex; align-items: center; justify-content: space-between; }
.gap-8 { gap: 8px; }
.gap-16 { gap: 16px; }
.gap-24 { gap: 24px; }
.hidden { display: none !important; }
.show-more-btn {
  display: block;
  margin: 30px auto 0;
  padding: 11px 36px;
  background: transparent;
  border: 2px solid var(--primary);
  color: var(--primary);
  border-radius: 24px;
  font-size: 14px;
  font-weight: 700;
  cursor: pointer;
  transition: var(--transition);
}
.show-more-btn:hover { background: var(--primary); color: var(--white); }

/* ================================================
   Footer 信任背书条
   ================================================ */
.footer-trust {
  display: flex;
  flex-wrap: wrap;
  gap: 12px 24px;
  justify-content: center;
  padding: 20px 0;
  border-top: 1px solid rgba(255,255,255,0.08);
  border-bottom: 1px solid rgba(255,255,255,0.08);
  margin: 24px 0;
}
.trust-item {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 13px;
  color: rgba(255,255,255,0.65);
}
.trust-item span { font-size: 16px; }

/* ================================================
   新闻动态卡片
   ================================================ */
.news-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}
.news-card {
  background: var(--white);
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow);
  transition: var(--transition);
}
.news-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-lg); }
.news-card-img {
  width: 100%;
  aspect-ratio: 16/9;
  object-fit: cover;
}
.news-card-body { padding: 18px; }
.news-card-cat {
  display: inline-block;
  background: rgba(10,110,138,0.1);
  color: var(--primary);
  font-size: 11px;
  font-weight: 700;
  padding: 2px 10px;
  border-radius: 10px;
  margin-bottom: 8px;
}
.news-card-body h3 {
  font-size: 15px;
  font-weight: 700;
  color: var(--dark);
  margin-bottom: 8px;
  line-height: 1.5;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}
.news-card-body p {
  font-size: 13px;
  color: var(--text-muted);
  line-height: 1.6;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
  margin-bottom: 12px;
}
.news-card-meta {
  display: flex;
  justify-content: space-between;
  font-size: 12px;
  color: var(--text-muted);
}
.news-card-meta a { color: var(--primary); font-weight: 600; }

/* ================================================
   隐私/协议页面
   ================================================ */
.legal-content {
  max-width: 800px;
  margin: 0 auto;
  background: var(--white);
  border-radius: var(--radius-lg);
  padding: 40px;
  box-shadow: var(--shadow);
}
.legal-content h2 { font-size: 20px; font-weight: 800; color: var(--dark); margin: 28px 0 12px; border-left: 4px solid var(--primary); padding-left: 12px; }
.legal-content h3 { font-size: 16px; font-weight: 700; color: var(--dark); margin: 20px 0 8px; }
.legal-content p  { font-size: 14px; color: var(--text-muted); line-height: 1.9; margin-bottom: 12px; }
.legal-content ul { padding-left: 20px; margin-bottom: 12px; }
.legal-content ul li { font-size: 14px; color: var(--text-muted); line-height: 1.8; list-style: disc; }

/* ================================================
   响应式补充
   ================================================ */
@media (max-width: 992px) {
  .news-grid { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 768px) {
  .footer-trust { gap: 10px 16px; }
  .news-grid { grid-template-columns: 1fr; }
  .legal-content { padding: 24px 16px; }
}

/* ============================================================
   补充样式：视频卡片增强、新页面样式
   ============================================================ */

/* 视频热播标签 */
.video-hot-tag {
  position: absolute;
  top: 8px;
  left: 8px;
  background: linear-gradient(135deg, #e74c3c, #c0392b);
  color: #fff;
  font-size: 11px;
  font-weight: 700;
  padding: 3px 8px;
  border-radius: 10px;
  z-index: 3;
  white-space: nowrap;
}

/* 视频分类标签 */
.video-cat {
  display: inline-block;
  background: rgba(10,110,138,0.1);
  color: #0a6e8a;
  font-size: 11px;
  font-weight: 700;
  padding: 2px 8px;
  border-radius: 8px;
  margin-bottom: 6px;
}

/* 视频标题 */
.video-title {
  font-size: 13px;
  font-weight: 700;
  color: var(--dark);
  line-height: 1.5;
  margin-bottom: 8px;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

/* 视频网格3列 */
.video-grid-3 {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}

/* 合作伙伴网格 */
.partner-grid {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  justify-content: center;
  align-items: center;
}
.partner-item {
  display: flex;
  align-items: center;
  gap: 8px;
  background: #fff;
  border: 1.5px solid var(--border);
  border-radius: 10px;
  padding: 10px 20px;
  font-size: 14px;
  font-weight: 700;
  color: var(--text);
  transition: var(--transition);
}
.partner-item:hover {
  border-color: var(--primary);
  color: var(--primary);
  box-shadow: var(--shadow);
}
.p-icon { font-size: 18px; }

/* 用户评价网格 */
.review-card {
  background: #fff;
  border-radius: var(--radius);
  padding: 20px;
  box-shadow: var(--shadow);
  border: 1px solid var(--border);
}
.review-header {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 12px;
}
.reviewer-avatar {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--primary), var(--teal));
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 18px;
  flex-shrink: 0;
}
.reviewer-name { font-size: 14px; font-weight: 700; color: var(--dark); }
.review-stars { font-size: 12px; margin-top: 2px; }
.review-date { font-size: 11px; color: var(--text-muted); margin-left: auto; }
.review-text { font-size: 13px; color: var(--text-muted); line-height: 1.7; }

/* 社区卡片 */
.community-card {
  background: #fff;
  border-radius: var(--radius);
  padding: 24px 20px;
  text-align: center;
  border: 1.5px solid var(--border);
  transition: var(--transition);
}
.community-card:hover {
  border-color: var(--primary);
  box-shadow: var(--shadow);
  transform: translateY(-4px);
}
.comm-icon {
  font-size: 32px;
  margin-bottom: 12px;
  display: block;
}
.community-card h3 {
  font-size: 15px;
  font-weight: 800;
  color: var(--dark);
  margin-bottom: 8px;
}
.community-card p {
  font-size: 12px;
  color: var(--text-muted);
  line-height: 1.6;
  margin-bottom: 10px;
}
.comm-count {
  font-size: 11px;
  color: var(--primary);
  font-weight: 700;
  background: rgba(10,110,138,0.08);
  padding: 3px 10px;
  border-radius: 10px;
}

/* 专家卡片 */
.expert-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}
.expert-card {
  background: #fff;
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow);
  border: 1px solid var(--border);
  transition: var(--transition);
}
.expert-card:hover { transform: translateY(-6px); box-shadow: var(--shadow-lg); }
.expert-photo {
  position: relative;
  height: 200px;
  overflow: hidden;
}
.expert-photo img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.4s;
}
.expert-card:hover .expert-photo img { transform: scale(1.05); }
.expert-badge {
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  background: linear-gradient(to top, rgba(10,110,138,0.9), transparent);
  color: #fff;
  font-size: 12px;
  font-weight: 700;
  padding: 20px 12px 8px;
}
.expert-info {
  padding: 16px;
  text-align: center;
}
.expert-info h3 {
  font-size: 16px;
  font-weight: 800;
  color: var(--dark);
  margin-bottom: 4px;
}
.expert-title {
  font-size: 12px;
  color: var(--primary);
  font-weight: 700;
  margin-bottom: 8px;
}
.expert-desc {
  font-size: 12px;
  color: var(--text-muted);
  line-height: 1.6;
  margin-bottom: 10px;
}
.expert-btns {
  display: flex;
  gap: 8px;
  justify-content: center;
}
.btn-sm { padding: 5px 14px; border-radius: 16px; font-size: 12px; font-weight: 700; }
.btn-primary-sm {
  background: var(--primary);
  color: #fff;
  border: none;
}
.btn-outline-sm {
  background: transparent;
  color: var(--primary);
  border: 1.5px solid var(--primary);
}

/* 如何使用步骤 */
.howto-step {
  background: #fff;
  border-radius: var(--radius);
  padding: 24px 20px;
  text-align: center;
  border: 1px solid var(--border);
  position: relative;
}
.step-num {
  font-size: 36px;
  font-weight: 900;
  color: rgba(10,110,138,0.12);
  position: absolute;
  top: 12px;
  right: 16px;
  line-height: 1;
}
.step-icon {
  font-size: 28px;
  margin-bottom: 12px;
  display: block;
}
.howto-step h3 {
  font-size: 15px;
  font-weight: 800;
  color: var(--dark);
  margin-bottom: 8px;
}
.howto-step p {
  font-size: 13px;
  color: var(--text-muted);
  line-height: 1.7;
}

/* 新闻卡片 */
.news-card { transition: var(--transition); }
.news-card:hover h3 { color: var(--primary); }

/* tag-new */
.tag-new {
  background: linear-gradient(135deg, #e74c3c, #c0392b);
  color: #fff;
  font-size: 11px;
  font-weight: 700;
  padding: 3px 10px;
  border-radius: 10px;
}

/* 响应式补充 */
@media (max-width: 992px) {
  .video-grid-3 { grid-template-columns: repeat(2, 1fr); }
  .expert-grid { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 600px) {
  .video-grid-3 { grid-template-columns: 1fr; }
  .expert-grid { grid-template-columns: 1fr; }
  .community-grid { grid-template-columns: 1fr !important; }
}