/* ============================================================
   母狗 - 汽车改装视频社区 | bdnart.cn
   原创设计 | 深夜橙蓝配色方案
   ============================================================ */

/* ---- CSS变量 ---- */
:root {
  --color-primary: #0d1b2a;
  --color-secondary: #1b2d45;
  --color-accent: #ff6b1a;
  --color-accent-light: #ff8c42;
  --color-gold: #f0a500;
  --color-text: #e8edf2;
  --color-text-muted: #8a9bb0;
  --color-border: #243447;
  --color-card: #162030;
  --color-card-hover: #1e2f45;
  --color-white: #ffffff;
  --font-main: 'PingFang SC', 'Microsoft YaHei', 'Hiragino Sans GB', sans-serif;
  --font-en: 'Segoe UI', 'Roboto', Arial, sans-serif;
  --radius: 10px;
  --radius-lg: 18px;
  --shadow: 0 4px 24px rgba(0,0,0,0.35);
  --shadow-card: 0 2px 16px rgba(0,0,0,0.28);
  --transition: 0.3s cubic-bezier(0.4,0,0.2,1);
}

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

/* ---- 干扰标签全局隐藏 ---- */
.bdnart-noise { display: none !important; visibility: hidden !important; }

/* ---- 顶部公告栏 ---- */
.top-bar {
  background: linear-gradient(90deg, var(--color-accent) 0%, #c94e00 100%);
  padding: 7px 0;
  text-align: center;
  font-size: 13px;
  color: #fff;
  letter-spacing: 1px;
}
.top-bar a { color: #fff; font-weight: 600; }

/* ---- 导航栏 ---- */
.navbar {
  background: rgba(13,27,42,0.97);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--color-border);
  position: sticky;
  top: 0;
  z-index: 1000;
  box-shadow: 0 2px 20px rgba(0,0,0,0.4);
}
.navbar-inner {
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 24px;
  display: flex;
  align-items: center;
  height: 70px;
  gap: 32px;
}
.navbar-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-shrink: 0;
}
.navbar-logo img {
  width: 44px;
  height: 44px;
  object-fit: contain;
  border-radius: 8px;
}
.navbar-logo .brand-name {
  font-size: 22px;
  font-weight: 800;
  color: var(--color-white);
  letter-spacing: 2px;
}
.navbar-logo .brand-name span { color: var(--color-accent); }
.navbar-nav {
  display: flex;
  align-items: center;
  gap: 4px;
  flex: 1;
}
.navbar-nav a {
  color: var(--color-text-muted);
  font-size: 14px;
  font-weight: 500;
  padding: 8px 14px;
  border-radius: var(--radius);
  transition: all var(--transition);
  white-space: nowrap;
}
.navbar-nav a:hover,
.navbar-nav a.active {
  color: var(--color-white);
  background: rgba(255,107,26,0.15);
}
.navbar-nav a.active { color: var(--color-accent); }

/* ---- 搜索框 ---- */
.navbar-search {
  display: flex;
  align-items: center;
  background: var(--color-secondary);
  border: 1px solid var(--color-border);
  border-radius: 24px;
  padding: 6px 16px;
  gap: 8px;
  min-width: 200px;
  transition: border-color var(--transition);
}
.navbar-search:focus-within { border-color: var(--color-accent); }
.navbar-search input {
  background: none;
  border: none;
  outline: none;
  color: var(--color-text);
  font-size: 13px;
  width: 100%;
  font-family: var(--font-main);
}
.navbar-search input::placeholder { color: var(--color-text-muted); }
.navbar-search button {
  color: var(--color-text-muted);
  font-size: 15px;
  padding: 0;
  transition: color var(--transition);
}
.navbar-search button:hover { color: var(--color-accent); }
.navbar-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  cursor: pointer;
  padding: 4px;
}
.navbar-toggle span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--color-text);
  border-radius: 2px;
  transition: all var(--transition);
}

/* ---- Hero 区域 ---- */
.hero {
  position: relative;
  min-height: 90vh;
  display: flex;
  align-items: center;
  overflow: hidden;
}
.hero-bg {
  position: absolute;
  inset: 0;
  background-image: url('../images/hero-bg.jpg');
  background-size: cover;
  background-position: center;
  filter: brightness(0.45);
  transform: scale(1.03);
  transition: transform 8s ease;
}
.hero:hover .hero-bg { transform: scale(1.0); }
.hero-overlay {
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, rgba(13,27,42,0.85) 0%, rgba(255,107,26,0.08) 100%);
}
.hero-content {
  position: relative;
  z-index: 2;
  max-width: 1280px;
  margin: 0 auto;
  padding: 80px 24px;
  width: 100%;
}
.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: rgba(255,107,26,0.18);
  border: 1px solid rgba(255,107,26,0.4);
  border-radius: 20px;
  padding: 6px 16px;
  font-size: 13px;
  color: var(--color-accent-light);
  margin-bottom: 24px;
}
.hero-badge::before {
  content: '';
  width: 8px; height: 8px;
  background: var(--color-accent);
  border-radius: 50%;
  animation: blink 1.5s infinite;
}
@keyframes blink { 0%,100%{opacity:1} 50%{opacity:0.3} }
.hero h1 {
  font-size: clamp(36px, 6vw, 72px);
  font-weight: 900;
  line-height: 1.15;
  color: var(--color-white);
  margin-bottom: 20px;
  letter-spacing: -1px;
}
.hero h1 .accent { color: var(--color-accent); }
.hero-desc {
  font-size: clamp(15px, 2vw, 18px);
  color: rgba(232,237,242,0.8);
  max-width: 600px;
  margin-bottom: 40px;
  line-height: 1.8;
}
.hero-actions { display: flex; gap: 16px; flex-wrap: wrap; }
.btn-primary {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: linear-gradient(135deg, var(--color-accent) 0%, #c94e00 100%);
  color: #fff;
  padding: 14px 32px;
  border-radius: 30px;
  font-size: 15px;
  font-weight: 700;
  letter-spacing: 1px;
  box-shadow: 0 4px 20px rgba(255,107,26,0.4);
  transition: all var(--transition);
}
.btn-primary:hover {
  color: #fff;
  transform: translateY(-2px);
  box-shadow: 0 8px 28px rgba(255,107,26,0.55);
}
.btn-outline {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  border: 2px solid rgba(255,255,255,0.3);
  color: var(--color-white);
  padding: 12px 28px;
  border-radius: 30px;
  font-size: 15px;
  font-weight: 600;
  transition: all var(--transition);
}
.btn-outline:hover {
  color: var(--color-white);
  border-color: var(--color-accent);
  background: rgba(255,107,26,0.12);
}
.hero-stats {
  display: flex;
  gap: 40px;
  margin-top: 60px;
  flex-wrap: wrap;
}
.hero-stat { text-align: left; }
.hero-stat .num {
  font-size: 36px;
  font-weight: 900;
  color: var(--color-accent);
  line-height: 1;
}
.hero-stat .label {
  font-size: 13px;
  color: var(--color-text-muted);
  margin-top: 4px;
}

/* ---- 通用区块 ---- */
.section {
  padding: 80px 0;
}
.section-alt { background: var(--color-secondary); }
.container {
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 24px;
}
.section-header {
  text-align: center;
  margin-bottom: 56px;
}
.section-tag {
  display: inline-block;
  background: rgba(255,107,26,0.12);
  color: var(--color-accent);
  border: 1px solid rgba(255,107,26,0.3);
  border-radius: 20px;
  padding: 4px 14px;
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 2px;
  text-transform: uppercase;
  margin-bottom: 12px;
}
.section-title {
  font-size: clamp(26px, 4vw, 42px);
  font-weight: 800;
  color: var(--color-white);
  line-height: 1.3;
  margin-bottom: 14px;
}
.section-title .accent { color: var(--color-accent); }
.section-desc {
  font-size: 15px;
  color: var(--color-text-muted);
  max-width: 560px;
  margin: 0 auto;
  line-height: 1.8;
}

/* ---- 视频卡片 ---- */
.video-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 24px;
}
.video-card {
  background: var(--color-card);
  border-radius: var(--radius-lg);
  overflow: hidden;
  border: 1px solid var(--color-border);
  transition: all var(--transition);
  cursor: pointer;
}
.video-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow);
  border-color: rgba(255,107,26,0.3);
}
.video-thumb {
  position: relative;
  aspect-ratio: 16/9;
  overflow: hidden;
}
.video-thumb img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform var(--transition);
}
.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(0,0,0,0.3);
  opacity: 0;
  transition: opacity var(--transition);
}
.video-card:hover .video-play-btn { opacity: 1; }
.play-icon {
  width: 60px;
  height: 60px;
  background: rgba(255,107,26,0.9);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 4px 20px rgba(255,107,26,0.5);
  transform: scale(0.8);
  transition: transform var(--transition);
}
.video-card:hover .play-icon { transform: scale(1); }
.play-icon::after {
  content: '';
  border-style: solid;
  border-width: 10px 0 10px 18px;
  border-color: transparent transparent transparent #fff;
  margin-left: 4px;
}
.video-duration {
  position: absolute;
  bottom: 10px;
  right: 10px;
  background: rgba(0,0,0,0.75);
  color: #fff;
  font-size: 12px;
  padding: 2px 8px;
  border-radius: 4px;
  font-family: var(--font-en);
}
.video-category-tag {
  position: absolute;
  top: 10px;
  left: 10px;
  background: var(--color-accent);
  color: #fff;
  font-size: 11px;
  padding: 3px 10px;
  border-radius: 4px;
  font-weight: 600;
}
.video-info {
  padding: 16px;
}
.video-title {
  font-size: 15px;
  font-weight: 700;
  color: var(--color-white);
  line-height: 1.5;
  margin-bottom: 10px;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}
.video-meta {
  display: flex;
  align-items: center;
  gap: 16px;
  font-size: 12px;
  color: var(--color-text-muted);
}
.video-meta span { display: flex; align-items: center; gap: 4px; }

/* ---- 功能模块卡片 ---- */
.feature-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 24px;
}
.feature-card {
  background: var(--color-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 32px 28px;
  transition: all var(--transition);
}
.feature-card:hover {
  border-color: rgba(255,107,26,0.4);
  background: var(--color-card-hover);
  transform: translateY(-4px);
  box-shadow: var(--shadow-card);
}
.feature-icon {
  width: 56px;
  height: 56px;
  background: linear-gradient(135deg, rgba(255,107,26,0.2) 0%, rgba(255,107,26,0.05) 100%);
  border: 1px solid rgba(255,107,26,0.25);
  border-radius: 14px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 26px;
  margin-bottom: 20px;
}
.feature-title {
  font-size: 17px;
  font-weight: 700;
  color: var(--color-white);
  margin-bottom: 10px;
}
.feature-desc {
  font-size: 13px;
  color: var(--color-text-muted);
  line-height: 1.7;
}

/* ---- 专家卡片 ---- */
.expert-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 28px;
}
.expert-card {
  background: var(--color-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  overflow: hidden;
  transition: all var(--transition);
}
.expert-card:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow);
  border-color: rgba(255,107,26,0.3);
}
.expert-photo {
  width: 100%;
  aspect-ratio: 4/3;
  object-fit: cover;
}
.expert-body { padding: 22px; }
.expert-name {
  font-size: 18px;
  font-weight: 800;
  color: var(--color-white);
  margin-bottom: 4px;
}
.expert-role {
  font-size: 13px;
  color: var(--color-accent);
  font-weight: 600;
  margin-bottom: 12px;
}
.expert-desc {
  font-size: 13px;
  color: var(--color-text-muted);
  line-height: 1.7;
  margin-bottom: 16px;
}
.expert-awards {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin-bottom: 16px;
}
.award-badge {
  background: rgba(240,165,0,0.12);
  border: 1px solid rgba(240,165,0,0.3);
  color: var(--color-gold);
  font-size: 11px;
  padding: 3px 10px;
  border-radius: 4px;
}
.expert-actions { display: flex; gap: 10px; }
.btn-sm {
  flex: 1;
  text-align: center;
  padding: 8px 12px;
  border-radius: 8px;
  font-size: 13px;
  font-weight: 600;
  transition: all var(--transition);
}
.btn-sm-primary {
  background: var(--color-accent);
  color: #fff;
}
.btn-sm-primary:hover { background: var(--color-accent-light); color: #fff; }
.btn-sm-outline {
  border: 1px solid var(--color-border);
  color: var(--color-text-muted);
}
.btn-sm-outline:hover { border-color: var(--color-accent); color: var(--color-accent); }

/* ---- 合作品牌 ---- */
.partner-grid {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  justify-content: center;
  align-items: center;
}
.partner-item {
  background: var(--color-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 16px 28px;
  font-size: 14px;
  font-weight: 700;
  color: var(--color-text-muted);
  transition: all var(--transition);
  letter-spacing: 1px;
}
.partner-item:hover {
  border-color: var(--color-accent);
  color: var(--color-white);
  background: var(--color-card-hover);
}

/* ---- 用户评价 ---- */
.review-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 24px;
}
.review-card {
  background: var(--color-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 28px;
  transition: all var(--transition);
}
.review-card:hover {
  border-color: rgba(255,107,26,0.25);
  transform: translateY(-3px);
}
.review-stars { color: var(--color-gold); font-size: 16px; margin-bottom: 14px; }
.review-text {
  font-size: 14px;
  color: var(--color-text);
  line-height: 1.8;
  margin-bottom: 20px;
  font-style: italic;
}
.review-author { display: flex; align-items: center; gap: 12px; }
.review-avatar {
  width: 42px;
  height: 42px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--color-accent) 0%, var(--color-secondary) 100%);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 16px;
  font-weight: 700;
  color: #fff;
  flex-shrink: 0;
}
.review-name { font-size: 14px; font-weight: 700; color: var(--color-white); }
.review-date { font-size: 12px; color: var(--color-text-muted); }

/* ---- FAQ ---- */
.faq-list { max-width: 860px; margin: 0 auto; }
.faq-item {
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  margin-bottom: 12px;
  overflow: hidden;
  transition: border-color var(--transition);
}
.faq-item.open { border-color: rgba(255,107,26,0.4); }
.faq-question {
  width: 100%;
  text-align: left;
  padding: 20px 24px;
  font-size: 15px;
  font-weight: 600;
  color: var(--color-white);
  background: var(--color-card);
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 16px;
  transition: background var(--transition);
}
.faq-question:hover { background: var(--color-card-hover); }
.faq-icon {
  width: 24px;
  height: 24px;
  border: 1px solid var(--color-border);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 16px;
  color: var(--color-accent);
  flex-shrink: 0;
  transition: transform var(--transition);
}
.faq-item.open .faq-icon { transform: rotate(45deg); }
.faq-answer {
  padding: 0 24px;
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.4s ease, padding 0.3s;
  font-size: 14px;
  color: var(--color-text-muted);
  line-height: 1.8;
  background: var(--color-card);
}
.faq-item.open .faq-answer { max-height: 300px; padding: 0 24px 20px; }

/* ---- 联系我们 ---- */
.contact-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 40px;
  align-items: start;
}
.contact-info-block {
  background: var(--color-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 36px;
}
.contact-info-block h3 {
  font-size: 20px;
  font-weight: 800;
  color: var(--color-white);
  margin-bottom: 24px;
  padding-bottom: 16px;
  border-bottom: 1px solid var(--color-border);
}
.contact-item {
  display: flex;
  gap: 14px;
  margin-bottom: 20px;
  align-items: flex-start;
}
.contact-icon {
  width: 40px;
  height: 40px;
  background: rgba(255,107,26,0.12);
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 18px;
  flex-shrink: 0;
}
.contact-label { font-size: 12px; color: var(--color-text-muted); margin-bottom: 4px; }
.contact-value { font-size: 14px; color: var(--color-white); font-weight: 600; }
.qr-grid { display: flex; gap: 24px; flex-wrap: wrap; }
.qr-item { text-align: center; }
.qr-item img { width: 120px; height: 120px; border-radius: var(--radius); border: 1px solid var(--color-border); }
.qr-label { font-size: 12px; color: var(--color-text-muted); margin-top: 8px; }

/* ---- 社区加入指南 ---- */
.join-steps {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
  gap: 24px;
}
.join-step {
  background: var(--color-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 28px 22px;
  text-align: center;
  position: relative;
  transition: all var(--transition);
}
.join-step:hover { border-color: rgba(255,107,26,0.35); transform: translateY(-4px); }
.step-num {
  width: 44px;
  height: 44px;
  background: linear-gradient(135deg, var(--color-accent), #c94e00);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 18px;
  font-weight: 900;
  color: #fff;
  margin: 0 auto 16px;
}
.step-title { font-size: 15px; font-weight: 700; color: var(--color-white); margin-bottom: 8px; }
.step-desc { font-size: 13px; color: var(--color-text-muted); line-height: 1.7; }

/* ---- AI赋能区块 ---- */
.ai-section { background: linear-gradient(135deg, #0a1520 0%, #0d1b2a 50%, #0a1520 100%); }
.ai-card {
  background: linear-gradient(135deg, rgba(255,107,26,0.08) 0%, rgba(13,27,42,0.9) 100%);
  border: 1px solid rgba(255,107,26,0.2);
  border-radius: var(--radius-lg);
  padding: 32px;
  transition: all var(--transition);
}
.ai-card:hover { border-color: rgba(255,107,26,0.5); box-shadow: 0 0 30px rgba(255,107,26,0.1); }

/* ---- 分享按钮 ---- */
.share-bar {
  display: flex;
  align-items: center;
  gap: 12px;
  flex-wrap: wrap;
}
.share-label { font-size: 13px; color: var(--color-text-muted); }
.share-btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 7px 16px;
  border-radius: 20px;
  font-size: 13px;
  font-weight: 600;
  border: 1px solid var(--color-border);
  color: var(--color-text-muted);
  transition: all var(--transition);
}
.share-btn:hover { color: var(--color-white); border-color: var(--color-accent); background: rgba(255,107,26,0.1); }
.share-btn.wechat:hover { border-color: #07c160; color: #07c160; background: rgba(7,193,96,0.08); }
.share-btn.weibo:hover { border-color: #e6162d; color: #e6162d; background: rgba(230,22,45,0.08); }
.share-btn.douyin:hover { border-color: #fe2c55; color: #fe2c55; background: rgba(254,44,85,0.08); }
.share-btn.bilibili:hover { border-color: #00a1d6; color: #00a1d6; background: rgba(0,161,214,0.08); }

/* ---- 页脚 ---- */
.footer {
  background: #080f18;
  border-top: 1px solid var(--color-border);
  padding: 60px 0 0;
}
.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 40px;
  margin-bottom: 48px;
}
.footer-brand .brand-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 16px;
}
.footer-brand .brand-logo img { width: 40px; height: 40px; border-radius: 8px; }
.footer-brand .brand-logo span { font-size: 20px; font-weight: 800; color: var(--color-white); }
.footer-brand p { font-size: 13px; color: var(--color-text-muted); line-height: 1.8; margin-bottom: 20px; }
.footer-col h4 {
  font-size: 14px;
  font-weight: 700;
  color: var(--color-white);
  margin-bottom: 16px;
  padding-bottom: 10px;
  border-bottom: 1px solid var(--color-border);
}
.footer-col ul li { margin-bottom: 10px; }
.footer-col ul li a { font-size: 13px; color: var(--color-text-muted); transition: color var(--transition); }
.footer-col ul li a:hover { color: var(--color-accent); }
.footer-bottom {
  border-top: 1px solid var(--color-border);
  padding: 20px 0;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 12px;
}
.footer-bottom p { font-size: 12px; color: var(--color-text-muted); }
.footer-bottom a { color: var(--color-text-muted); }
.footer-bottom a:hover { color: var(--color-accent); }

/* ---- 面包屑 ---- */
.breadcrumb {
  padding: 16px 0;
  font-size: 13px;
  color: var(--color-text-muted);
}
.breadcrumb a { color: var(--color-text-muted); }
.breadcrumb a:hover { color: var(--color-accent); }
.breadcrumb span { margin: 0 8px; }

/* ---- 内页 Banner ---- */
.page-banner {
  background: linear-gradient(135deg, var(--color-secondary) 0%, var(--color-primary) 100%);
  padding: 60px 0;
  border-bottom: 1px solid var(--color-border);
}
.page-banner h1 {
  font-size: clamp(28px, 4vw, 48px);
  font-weight: 900;
  color: var(--color-white);
  margin-bottom: 12px;
}
.page-banner p { font-size: 15px; color: var(--color-text-muted); }

/* ---- 标签云 ---- */
.tag-cloud { display: flex; flex-wrap: wrap; gap: 10px; }
.tag {
  background: var(--color-card);
  border: 1px solid var(--color-border);
  color: var(--color-text-muted);
  padding: 6px 14px;
  border-radius: 20px;
  font-size: 13px;
  transition: all var(--transition);
  cursor: pointer;
}
.tag:hover, .tag.active {
  background: rgba(255,107,26,0.12);
  border-color: var(--color-accent);
  color: var(--color-accent);
}

/* ---- 滚动进度条 ---- */
.progress-bar {
  position: fixed;
  top: 0;
  left: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--color-accent), var(--color-gold));
  z-index: 9999;
  transition: width 0.1s;
}

/* ---- 回到顶部 ---- */
.back-to-top {
  position: fixed;
  bottom: 32px;
  right: 32px;
  width: 44px;
  height: 44px;
  background: var(--color-accent);
  color: #fff;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 18px;
  box-shadow: 0 4px 16px rgba(255,107,26,0.4);
  opacity: 0;
  pointer-events: none;
  transition: all var(--transition);
  z-index: 500;
}
.back-to-top.visible { opacity: 1; pointer-events: auto; }
.back-to-top:hover { color: #fff; background: var(--color-accent-light); transform: translateY(-3px); }

/* ---- 数据统计条 ---- */
.stats-bar {
  background: var(--color-secondary);
  border-top: 1px solid var(--color-border);
  border-bottom: 1px solid var(--color-border);
  padding: 32px 0;
}
.stats-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
  text-align: center;
}
.stat-item .num {
  font-size: 36px;
  font-weight: 900;
  color: var(--color-accent);
  font-family: var(--font-en);
  line-height: 1;
}
.stat-item .unit { font-size: 16px; color: var(--color-accent); }
.stat-item .label { font-size: 13px; color: var(--color-text-muted); margin-top: 6px; }

/* ---- 响应式 ---- */
@media (max-width: 1024px) {
  .footer-grid { grid-template-columns: 1fr 1fr; }
  .contact-grid { grid-template-columns: 1fr; }
  .stats-grid { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 768px) {
  .navbar-nav { display: none; }
  .navbar-nav.open {
    display: flex;
    flex-direction: column;
    position: absolute;
    top: 70px;
    left: 0;
    right: 0;
    background: rgba(13,27,42,0.98);
    padding: 16px;
    border-bottom: 1px solid var(--color-border);
    z-index: 999;
  }
  .navbar-search { display: none; }
  .navbar-toggle { display: flex; }
  .hero { min-height: 70vh; }
  .hero h1 { font-size: 32px; }
  .hero-stats { gap: 24px; }
  .footer-grid { grid-template-columns: 1fr; }
  .video-grid { grid-template-columns: 1fr; }
  .feature-grid { grid-template-columns: 1fr; }
  .expert-grid { grid-template-columns: 1fr; }
  .stats-grid { grid-template-columns: repeat(2, 1fr); }
  .section { padding: 56px 0; }
}
@media (max-width: 480px) {
  .hero-actions { flex-direction: column; }
  .btn-primary, .btn-outline { width: 100%; justify-content: center; }
  .stats-grid { grid-template-columns: 1fr 1fr; }
  .hero-stats { gap: 16px; }
  .hero-stat .num { font-size: 28px; }
}

/* ============================================================
   母狗 补充样式 v2.0 | bdnart.cn
   H5 video卡片 / Hero Logo / Footer Logo / EEAT信任信号
   ============================================================ */

/* ---- H5 video 标签样式（百度可识别视频内容） ---- */
.bdnart-video {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
  background: var(--color-primary);
  /* 默认静音不自动播放，悬停时JS触发 */
}
/* 视频卡片内的video容器需要relative定位 */
.video-thumb {
  position: relative;
}
/* 移动端video优化：确保在iOS/Android正常显示 */
@media (max-width: 768px) {
  .bdnart-video {
    pointer-events: none; /* 移动端禁止直接点击video，由卡片整体处理 */
  }
  .video-grid {
    grid-template-columns: 1fr;
  }
  .video-card {
    margin-bottom: 0;
  }
}
@media (max-width: 480px) {
  .video-thumb {
    aspect-ratio: 16/9;
  }
  .play-icon {
    width: 48px;
    height: 48px;
  }
}

/* ---- Hero 区域 Logo 大图展示 ---- */
.hero-logo-wrap {
  margin-bottom: 24px;
  display: flex;
  align-items: center;
  gap: 16px;
}
.hero-logo {
  width: 90px;
  height: 90px;
  border-radius: 18px;
  border: 3px solid rgba(255,107,26,0.6);
  box-shadow: 0 0 30px rgba(255,107,26,0.3);
  object-fit: cover;
}
.h1-video-keyword {
  color: var(--color-accent);
  font-style: normal;
  position: relative;
}
.h1-video-keyword::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 0;
  right: 0;
  height: 3px;
  background: var(--color-accent);
  border-radius: 2px;
}

/* ---- Footer Logo 大图区 ---- */
.footer-logo-area {
  display: flex;
  align-items: center;
  gap: 20px;
  padding: 40px 0 32px;
  border-bottom: 1px solid var(--color-border);
  margin-bottom: 40px;
}
.footer-logo-img {
  width: 100px;
  height: 100px;
  border-radius: 16px;
  border: 2px solid rgba(255,107,26,0.4);
  object-fit: cover;
  flex-shrink: 0;
}
.footer-brand-info {
  display: flex;
  flex-direction: column;
  gap: 6px;
}
.footer-brand-name {
  font-size: 28px;
  font-weight: 900;
  color: var(--color-white);
  letter-spacing: 3px;
}
.footer-brand-slogan {
  font-size: 14px;
  color: var(--color-text-muted);
  letter-spacing: 1px;
}
@media (max-width: 480px) {
  .footer-logo-area { flex-direction: column; text-align: center; }
  .footer-logo-img { width: 80px; height: 80px; }
  .footer-brand-name { font-size: 22px; }
}

/* ---- EEAT 信任信号徽章 ---- */
.eeat-badges {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 16px;
}
.eeat-badge {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  background: rgba(255,107,26,0.08);
  border: 1px solid rgba(255,107,26,0.25);
  color: var(--color-text-muted);
  font-size: 12px;
  padding: 4px 10px;
  border-radius: 20px;
}

/* ---- 社区亲密教育科普卡片 ---- */
.community-edu-card {
  border-color: rgba(240,165,0,0.25);
  background: linear-gradient(135deg, var(--color-card) 0%, rgba(240,165,0,0.05) 100%);
}
.community-edu-card .feature-icon {
  background: rgba(240,165,0,0.12);
  border-color: rgba(240,165,0,0.3);
}

/* ---- 专家卡片补充 ---- */
.expert-awards {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin: 12px 0;
}
.award-badge {
  background: rgba(255,107,26,0.1);
  border: 1px solid rgba(255,107,26,0.2);
  color: var(--color-text-muted);
  font-size: 11px;
  padding: 3px 8px;
  border-radius: 4px;
}
.expert-actions {
  display: flex;
  gap: 10px;
  margin-top: 16px;
}
.btn-sm {
  padding: 7px 16px;
  border-radius: 8px;
  font-size: 13px;
  font-weight: 600;
  transition: all var(--transition);
  display: inline-flex;
  align-items: center;
}
.btn-sm-primary {
  background: var(--color-accent);
  color: #fff;
}
.btn-sm-primary:hover { background: var(--color-accent-light); color: #fff; }
.btn-sm-outline {
  border: 1px solid var(--color-border);
  color: var(--color-text-muted);
}
.btn-sm-outline:hover { border-color: var(--color-accent); color: var(--color-accent); }

/* ---- 合作品牌网格 ---- */
.partner-grid {
  display: grid;
  grid-template-columns: repeat(6, 1fr);
  gap: 16px;
}
.partner-item {
  background: var(--color-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 20px 12px;
  text-align: center;
  font-weight: 700;
  font-size: 14px;
  color: var(--color-text-muted);
  letter-spacing: 1px;
  transition: all var(--transition);
}
.partner-item:hover {
  border-color: var(--color-accent);
  color: var(--color-accent);
  background: rgba(255,107,26,0.06);
}
@media (max-width: 768px) {
  .partner-grid { grid-template-columns: repeat(3, 1fr); }
}
@media (max-width: 480px) {
  .partner-grid { grid-template-columns: repeat(2, 1fr); }
}

/* ---- 加入社区步骤 ---- */
.join-steps {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
  margin-top: 40px;
}
.join-step {
  background: var(--color-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 28px 20px;
  text-align: center;
  position: relative;
  transition: all var(--transition);
}
.join-step:hover {
  border-color: rgba(255,107,26,0.3);
  transform: translateY(-4px);
}
.step-num {
  width: 48px;
  height: 48px;
  background: var(--color-accent);
  color: #fff;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 20px;
  font-weight: 900;
  margin: 0 auto 16px;
}
.step-title {
  font-size: 16px;
  font-weight: 700;
  color: var(--color-white);
  margin-bottom: 10px;
}
.step-desc {
  font-size: 13px;
  color: var(--color-text-muted);
  line-height: 1.7;
}
@media (max-width: 768px) {
  .join-steps { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 480px) {
  .join-steps { grid-template-columns: 1fr; }
}

/* ---- 用户评价网格 ---- */
.review-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}
.review-card {
  background: var(--color-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 24px;
  transition: all var(--transition);
}
.review-card:hover {
  border-color: rgba(255,107,26,0.25);
  transform: translateY(-4px);
}
.review-stars {
  color: var(--color-gold);
  font-size: 16px;
  margin-bottom: 12px;
  letter-spacing: 2px;
}
.review-text {
  font-size: 14px;
  color: var(--color-text);
  line-height: 1.8;
  margin-bottom: 20px;
  font-style: italic;
}
.review-author {
  display: flex;
  align-items: center;
  gap: 12px;
}
.review-avatar {
  width: 40px;
  height: 40px;
  background: var(--color-accent);
  color: #fff;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 16px;
  flex-shrink: 0;
}
.review-name {
  font-size: 13px;
  font-weight: 600;
  color: var(--color-white);
}
.review-date {
  font-size: 12px;
  color: var(--color-text-muted);
  margin-top: 2px;
}
@media (max-width: 1024px) {
  .review-grid { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 768px) {
  .review-grid { grid-template-columns: 1fr; }
}

/* ---- 联系区域 ---- */
.contact-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 40px;
}
.contact-info-block {
  background: var(--color-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 32px;
}
.contact-info-block h3 {
  font-size: 18px;
  font-weight: 700;
  color: var(--color-white);
  margin-bottom: 24px;
  padding-bottom: 16px;
  border-bottom: 1px solid var(--color-border);
}
.contact-item {
  display: flex;
  align-items: flex-start;
  gap: 14px;
  margin-bottom: 18px;
}
.contact-icon {
  font-size: 20px;
  flex-shrink: 0;
  margin-top: 2px;
}
.contact-label {
  font-size: 12px;
  color: var(--color-text-muted);
  margin-bottom: 2px;
}
.contact-value {
  font-size: 14px;
  color: var(--color-text);
  font-weight: 500;
}
@media (max-width: 768px) {
  .contact-grid { grid-template-columns: 1fr; }
}

/* ---- 隐私政策页 ---- */
.privacy-content {
  max-width: 800px;
  margin: 0 auto;
  padding: 60px 24px;
}
.privacy-content h2 {
  font-size: 22px;
  font-weight: 700;
  color: var(--color-white);
  margin: 32px 0 14px;
  padding-bottom: 10px;
  border-bottom: 1px solid var(--color-border);
}
.privacy-content p {
  font-size: 14px;
  color: var(--color-text-muted);
  line-height: 1.9;
  margin-bottom: 16px;
}
.privacy-content ul {
  list-style: disc;
  padding-left: 20px;
  margin-bottom: 16px;
}
.privacy-content ul li {
  font-size: 14px;
  color: var(--color-text-muted);
  line-height: 1.8;
  margin-bottom: 6px;
}

/* ---- AI卡片高亮 ---- */
.ai-section { background: linear-gradient(180deg, var(--color-primary) 0%, rgba(27,45,69,0.5) 100%); }
.ai-card {
  border-color: rgba(0,200,255,0.15);
  background: linear-gradient(135deg, var(--color-card) 0%, rgba(0,100,200,0.08) 100%);
}
.ai-card .feature-icon {
  background: rgba(0,150,255,0.1);
  border-color: rgba(0,150,255,0.25);
}

/* ---- 特性卡片 feature-link ---- */
.feature-link {
  display: inline-block;
  margin-top: 12px;
  font-size: 13px;
  font-weight: 600;
  color: var(--color-accent);
  transition: color var(--transition);
}
.feature-link:hover { color: var(--color-accent-light); }