/* ============================================================
   丝瓜视频 - 全站样式表 | cjyinp.cn
   原创设计 | 品牌色系：深紫 #1A0A3B + 电光紫 #7C3AED + 青蓝 #06B6D4
   百度SEO最佳实践 + 移动端优先 + 无障碍访问
   ============================================================ */

/* ---------- CSS 变量 ---------- */
:root {
  --primary: #7C3AED;
  --primary-dark: #5B21B6;
  --primary-light: #A78BFA;
  --accent: #06B6D4;
  --accent-light: #67E8F9;
  --bg-dark: #0D0820;
  --bg-card: #160D30;
  --bg-card2: #1E1040;
  --text-main: #F0EAFF;
  --text-muted: #9D8EC4;
  --text-white: #FFFFFF;
  --border: rgba(124,58,237,0.25);
  --gradient-main: linear-gradient(135deg, #7C3AED 0%, #06B6D4 100%);
  --gradient-hero: linear-gradient(160deg, #0D0820 0%, #1A0A3B 50%, #0D1F3C 100%);
  --shadow-card: 0 8px 32px rgba(124,58,237,0.18);
  --shadow-hover: 0 16px 48px rgba(124,58,237,0.35);
  --radius: 14px;
  --radius-sm: 8px;
  --transition: all 0.3s cubic-bezier(0.4,0,0.2,1);
  --header-h: 68px;
}

/* ---------- 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","Noto Sans SC",sans-serif;
  background: var(--bg-dark);
  color: var(--text-main);
  line-height: 1.7;
  overflow-x: hidden;
}
a { color: var(--accent); text-decoration: none; transition: var(--transition); }
a:hover { color: var(--accent-light); }
img { max-width: 100%; height: auto; display: block; }
ul { list-style: none; }
button { cursor: pointer; border: none; outline: none; }

/* ---------- 无障碍焦点 ---------- */
:focus-visible {
  outline: 2px solid var(--primary-light);
  outline-offset: 2px;
}

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

/* ---------- 通用容器 ---------- */
.container { max-width: 1200px; margin: 0 auto; padding: 0 20px; }
.section { padding: 80px 0; }
.section-sm { padding: 50px 0; }

/* ---------- 通用标题 ---------- */
.section-title {
  font-size: 2rem;
  font-weight: 700;
  text-align: center;
  margin-bottom: 12px;
  background: var(--gradient-main);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}
.section-subtitle {
  text-align: center;
  color: var(--text-muted);
  font-size: 1rem;
  margin-bottom: 48px;
}

/* ---------- 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 12px 28px;
  border-radius: 50px;
  font-size: 0.95rem;
  font-weight: 600;
  transition: var(--transition);
  cursor: pointer;
  border: none;
  text-decoration: none;
  white-space: nowrap;
}
.btn-primary {
  background: var(--gradient-main);
  color: #fff;
  box-shadow: 0 4px 20px rgba(124,58,237,0.35);
}
.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 32px rgba(124,58,237,0.5);
  color: #fff;
}
.btn-outline {
  background: transparent;
  color: var(--primary-light);
  border: 1.5px solid var(--primary);
}
.btn-outline:hover {
  background: rgba(124,58,237,0.15);
  color: var(--text-white);
  transform: translateY(-2px);
}
.btn-sm { padding: 8px 18px; font-size: 0.85rem; }

/* ============================================================
   顶部导航
   ============================================================ */
.site-header {
  position: sticky;
  top: 0;
  z-index: 1000;
  background: rgba(13,8,32,0.92);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border);
  transition: transform 0.3s ease, box-shadow 0.3s ease, background 0.3s ease;
}
/* 滚动后加深背景 */
.site-header.scrolled {
  background: rgba(13,8,32,0.98);
  box-shadow: 0 4px 24px rgba(0,0,0,0.4);
}
/* 向下滚动时隐藏header */
.site-header.hidden {
  transform: translateY(-100%);
}
.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: var(--header-h);
  gap: 20px;
}
.site-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-shrink: 0;
}
.site-logo img {
  height: 42px;
  width: auto;
  border-radius: 6px;
}
.site-logo span {
  font-size: 1.3rem;
  font-weight: 800;
  background: var(--gradient-main);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  letter-spacing: 1px;
}
.main-nav { display: flex; align-items: center; gap: 4px; }
.main-nav a {
  padding: 8px 14px;
  border-radius: var(--radius-sm);
  font-size: 0.92rem;
  font-weight: 500;
  color: var(--text-muted);
  white-space: nowrap;
  transition: var(--transition);
}
.main-nav a:hover,
.main-nav a.active {
  color: var(--text-white);
  background: rgba(124,58,237,0.18);
}
.header-search {
  display: flex;
  align-items: center;
  background: rgba(255,255,255,0.06);
  border: 1px solid var(--border);
  border-radius: 50px;
  padding: 6px 16px;
  gap: 8px;
  min-width: 160px;
  max-width: 220px;
  flex: 1;
  transition: var(--transition);
}
.header-search:focus-within {
  border-color: var(--primary);
  background: rgba(124,58,237,0.08);
}
.header-search input {
  background: none;
  border: none;
  outline: none;
  color: var(--text-main);
  font-size: 0.88rem;
  width: 100%;
  min-width: 0;
}
.header-search input::placeholder { color: var(--text-muted); }
.header-search button {
  background: none;
  color: var(--text-muted);
  font-size: 1rem;
  padding: 0;
  transition: var(--transition);
  flex-shrink: 0;
}
.header-search button:hover { color: var(--accent); }
.header-actions { display: flex; align-items: center; gap: 10px; flex-shrink: 0; }
.hamburger {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  padding: 6px;
}
.hamburger span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--text-main);
  border-radius: 2px;
  transition: var(--transition);
}
/* 汉堡菜单激活态 */
.hamburger.active span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.hamburger.active span:nth-child(2) { opacity: 0; transform: scaleX(0); }
.hamburger.active span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* ---------- 搜索提示弹窗 ---------- */
.search-tip {
  display: none;
  position: absolute;
  top: calc(var(--header-h) + 4px);
  left: 50%;
  transform: translateX(-50%);
  background: var(--bg-card2);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 16px 24px;
  min-width: 300px;
  max-width: 90vw;
  box-shadow: var(--shadow-card);
  z-index: 999;
}
.search-tip.show { display: block; }
.search-tip p { font-size: 0.9rem; color: var(--text-muted); }
.search-tip .hot-tags { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 10px; }
.search-tip .tag {
  background: rgba(124,58,237,0.15);
  border: 1px solid var(--border);
  color: var(--primary-light);
  padding: 4px 12px;
  border-radius: 50px;
  font-size: 0.82rem;
  cursor: pointer;
  transition: var(--transition);
}
.search-tip .tag:hover { background: var(--primary); color: #fff; }

/* ============================================================
   Hero Banner
   ============================================================ */
.hero {
  position: relative;
  min-height: 560px;
  display: flex;
  align-items: center;
  overflow: hidden;
}
.hero-bg {
  position: absolute;
  inset: 0;
  background: var(--gradient-hero);
  z-index: 0;
}
.hero-bg::after {
  content: '';
  position: absolute;
  inset: 0;
  background: url('/images/hero_banner.jpg') center/cover no-repeat;
  opacity: 0.25;
}
.hero-overlay {
  position: absolute;
  inset: 0;
  background: radial-gradient(ellipse at 30% 50%, rgba(124,58,237,0.18) 0%, transparent 70%);
  z-index: 1;
}
.hero .container { position: relative; z-index: 2; padding: 80px 20px; }
.hero-content { max-width: 680px; }
.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  background: rgba(124,58,237,0.2);
  border: 1px solid rgba(124,58,237,0.4);
  color: var(--primary-light);
  padding: 6px 16px;
  border-radius: 50px;
  font-size: 0.82rem;
  font-weight: 600;
  margin-bottom: 24px;
}
.hero h1 {
  font-size: 3rem;
  font-weight: 800;
  line-height: 1.2;
  color: var(--text-white);
  margin-bottom: 20px;
}
.hero h1 em {
  font-style: normal;
  background: var(--gradient-main);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}
.hero p {
  font-size: 1.05rem;
  color: var(--text-muted);
  margin-bottom: 32px;
  line-height: 1.8;
  max-width: 560px;
}
.hero-btns { display: flex; gap: 14px; flex-wrap: wrap; margin-bottom: 40px; }
.hero-stats {
  display: flex;
  gap: 36px;
  flex-wrap: wrap;
}
.hero-stats .stat { text-align: left; }
.hero-stats .stat-num {
  font-size: 1.6rem;
  font-weight: 800;
  background: var(--gradient-main);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}
.hero-stats .stat-label { font-size: 0.78rem; color: var(--text-muted); margin-top: 2px; }

/* ============================================================
   过滤器
   ============================================================ */
.filter-bar {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-bottom: 32px;
}
.filter-btn {
  padding: 8px 20px;
  border-radius: 50px;
  font-size: 0.88rem;
  font-weight: 500;
  background: rgba(124,58,237,0.1);
  border: 1px solid var(--border);
  color: var(--text-muted);
  transition: var(--transition);
}
.filter-btn:hover,
.filter-btn.active {
  background: var(--gradient-main);
  color: #fff;
  border-color: transparent;
  box-shadow: 0 4px 16px rgba(124,58,237,0.3);
}

/* ============================================================
   视频卡片
   ============================================================ */
.video-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 20px;
}
.video-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  transition: var(--transition);
  position: relative;
}
.video-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-hover);
  border-color: var(--primary);
}
.video-thumb {
  position: relative;
  aspect-ratio: 16/9;
  overflow: hidden;
  background: var(--bg-card2);
}
.video-thumb img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.5s ease;
}
.video-card:hover .video-thumb img { transform: scale(1.08); }

/* 播放按钮 - PC hover显示 */
.play-btn {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(13,8,32,0.45);
  opacity: 0;
  transition: opacity 0.3s ease;
  cursor: pointer;
}
.video-card:hover .play-btn { opacity: 1; }

/* 移动端：触摸时通过JS设置opacity，此处保持默认隐藏 */
@media (hover: none) {
  /* 触摸设备：默认显示半透明播放按钮提示 */
  .play-btn {
    opacity: 0;
    background: rgba(13,8,32,0.3);
  }
  /* 触摸设备上的卡片始终显示一个小的播放图标 */
  .video-thumb::after {
    content: '';
    position: absolute;
    bottom: 8px;
    right: 8px;
    width: 32px;
    height: 32px;
    background: rgba(124,58,237,0.8) url("data:image/svg+xml,%3Csvg viewBox='0 0 24 24' fill='white' xmlns='http://www.w3.org/2000/svg'%3E%3Cpath d='M8 5v14l11-7z'/%3E%3C/svg%3E") center/16px no-repeat;
    border-radius: 50%;
    pointer-events: none;
  }
}

.play-btn-icon {
  width: 54px;
  height: 54px;
  background: var(--gradient-main);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 0 24px rgba(124,58,237,0.6);
  transform: scale(0.85);
  transition: var(--transition);
}
.video-card:hover .play-btn-icon { transform: scale(1); }
.play-btn-icon svg { width: 22px; height: 22px; fill: #fff; margin-left: 3px; }
.video-tag {
  position: absolute;
  top: 10px;
  left: 10px;
  background: var(--gradient-main);
  color: #fff;
  font-size: 0.72rem;
  font-weight: 600;
  padding: 3px 10px;
  border-radius: 50px;
  z-index: 1;
}
.video-duration {
  position: absolute;
  bottom: 8px;
  right: 8px;
  background: rgba(0,0,0,0.7);
  color: #fff;
  font-size: 0.75rem;
  padding: 2px 8px;
  border-radius: 4px;
  z-index: 1;
}
.video-info { padding: 14px 16px; }
.video-title {
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--text-main);
  margin-bottom: 8px;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
  line-height: 1.5;
}
.video-meta {
  display: flex;
  align-items: center;
  gap: 12px;
  font-size: 0.78rem;
  color: var(--text-muted);
  flex-wrap: wrap;
}
.video-meta span { display: flex; align-items: center; gap: 3px; }

/* ============================================================
   功能模块卡片
   ============================================================ */
.feature-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 24px;
}
.feature-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 28px 24px;
  transition: var(--transition);
}
.feature-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-hover);
  border-color: var(--primary);
}
.feature-icon {
  width: 52px;
  height: 52px;
  background: rgba(124,58,237,0.15);
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.6rem;
  margin-bottom: 18px;
}
.feature-card h3 {
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--text-white);
  margin-bottom: 10px;
}
.feature-card p {
  font-size: 0.88rem;
  color: var(--text-muted);
  line-height: 1.7;
}

/* ============================================================
   内容块（图文）
   ============================================================ */
.content-block {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 60px;
  align-items: center;
}
.content-block.reverse { direction: rtl; }
.content-block.reverse > * { direction: ltr; }
.content-block-img {
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: var(--shadow-hover);
}
.content-block-img img { width: 100%; height: 100%; object-fit: cover; }
.content-block-text h2 {
  font-size: 1.8rem;
  font-weight: 800;
  color: var(--text-white);
  margin-bottom: 16px;
  line-height: 1.3;
}
.content-block-text p {
  font-size: 0.92rem;
  color: var(--text-muted);
  margin-bottom: 14px;
  line-height: 1.8;
}
.content-block-text ul {
  margin: 16px 0;
  padding-left: 0;
}
.content-block-text ul li {
  font-size: 0.9rem;
  color: var(--text-muted);
  padding: 6px 0 6px 20px;
  position: relative;
}
.content-block-text ul li::before {
  content: '▸';
  position: absolute;
  left: 0;
  color: var(--primary-light);
}

/* ============================================================
   社区卡片
   ============================================================ */
.community-cards {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  gap: 20px;
}
.community-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px 20px;
  text-align: center;
  transition: var(--transition);
}
.community-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-hover);
  border-color: var(--primary);
}
.community-card .icon { font-size: 2rem; margin-bottom: 12px; }
.community-card h4 {
  font-size: 0.95rem;
  font-weight: 700;
  color: var(--text-white);
  margin-bottom: 8px;
}
.community-card p { font-size: 0.82rem; color: var(--text-muted); line-height: 1.6; }

/* ============================================================
   专家团队
   ============================================================ */
.experts-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
  gap: 24px;
}
.expert-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  transition: var(--transition);
}
.expert-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-hover);
  border-color: var(--primary);
}
.expert-photo {
  width: 100%;
  aspect-ratio: 3/4;
  object-fit: cover;
}
.expert-info { padding: 18px 16px; }
.expert-name {
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--text-white);
  margin-bottom: 4px;
}
.expert-title {
  font-size: 0.8rem;
  color: var(--primary-light);
  margin-bottom: 10px;
}
.expert-desc {
  font-size: 0.82rem;
  color: var(--text-muted);
  line-height: 1.6;
  margin-bottom: 12px;
}
.expert-tags { display: flex; flex-wrap: wrap; gap: 6px; margin-bottom: 14px; }
.expert-tag {
  background: rgba(124,58,237,0.12);
  border: 1px solid rgba(124,58,237,0.2);
  color: var(--primary-light);
  padding: 3px 10px;
  border-radius: 50px;
  font-size: 0.75rem;
}
.expert-btns { display: flex; gap: 8px; }

/* ============================================================
   数据统计条
   ============================================================ */
.stats-bar {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 32px 24px;
}
.stat-item { text-align: center; }
.stat-item .num {
  font-size: 2rem;
  font-weight: 800;
  background: var(--gradient-main);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  margin-bottom: 6px;
}
.stat-item .label { font-size: 0.85rem; color: var(--text-muted); }

/* ============================================================
   How-To 步骤
   ============================================================ */
.howto-steps {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
  gap: 24px;
  counter-reset: step;
}
.howto-step {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 28px 22px;
  position: relative;
  transition: var(--transition);
  counter-increment: step;
}
.howto-step:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-hover);
  border-color: var(--primary);
}
.howto-step::before {
  content: "0" counter(step);
  position: absolute;
  top: 18px;
  right: 18px;
  font-size: 2rem;
  font-weight: 900;
  background: var(--gradient-main);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  opacity: 0.3;
}
.howto-step h4 {
  font-size: 1rem;
  font-weight: 700;
  color: var(--text-white);
  margin-bottom: 10px;
}
.howto-step p { font-size: 0.85rem; color: var(--text-muted); line-height: 1.6; }

/* ============================================================
   合作伙伴
   ============================================================ */
.partners-row {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  justify-content: center;
  margin-top: 8px;
}
.partner-item {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 12px 24px;
  font-size: 0.88rem;
  color: var(--text-muted);
  transition: var(--transition);
  white-space: nowrap;
}
.partner-item:hover {
  border-color: var(--primary);
  color: var(--primary-light);
  background: rgba(124,58,237,0.08);
}

/* ============================================================
   用户评价
   ============================================================ */
.reviews-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 20px;
}
.review-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px 20px;
  transition: var(--transition);
}
.review-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-hover);
  border-color: var(--primary);
}
.review-stars { color: #FCD34D; font-size: 0.95rem; margin-bottom: 12px; letter-spacing: 2px; }
.review-text {
  font-size: 0.88rem;
  color: var(--text-muted);
  line-height: 1.7;
  margin-bottom: 16px;
}
.reviewer { display: flex; align-items: center; gap: 12px; }
.reviewer-avatar {
  width: 40px;
  height: 40px;
  background: var(--gradient-main);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.9rem;
  font-weight: 700;
  color: #fff;
  flex-shrink: 0;
}
.reviewer-name { font-size: 0.9rem; font-weight: 600; color: var(--text-white); }
.reviewer-meta { font-size: 0.75rem; color: var(--text-muted); margin-top: 2px; }

/* ============================================================
   FAQ
   ============================================================ */
.faq-list { max-width: 860px; margin: 0 auto; }
.faq-item {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  margin-bottom: 12px;
  overflow: hidden;
  transition: var(--transition);
}
.faq-item.open { border-color: var(--primary); }
.faq-question {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 18px 22px;
  cursor: pointer;
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--text-main);
  transition: var(--transition);
  user-select: none;
}
.faq-question:hover { color: var(--primary-light); }
.faq-icon {
  width: 24px;
  height: 24px;
  background: rgba(124,58,237,0.15);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.9rem;
  color: var(--primary-light);
  transition: var(--transition);
  flex-shrink: 0;
}
.faq-item.open .faq-icon { transform: rotate(45deg); background: var(--primary); color: #fff; }
.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.4s ease, padding 0.4s ease;
}
.faq-answer-inner {
  padding: 0 22px 18px;
  font-size: 0.88rem;
  color: var(--text-muted);
  line-height: 1.8;
}
/* FAQ展开高度：足够容纳长文本 */
.faq-item.open .faq-answer { max-height: 600px; }

/* ============================================================
   联系我们
   ============================================================ */
.contact-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 48px;
  align-items: start;
}
.contact-info h3 {
  font-size: 1.2rem;
  font-weight: 700;
  color: var(--text-white);
  margin-bottom: 24px;
}
.contact-item {
  display: flex;
  align-items: flex-start;
  gap: 14px;
  margin-bottom: 18px;
}
.contact-icon {
  width: 40px;
  height: 40px;
  background: rgba(124,58,237,0.15);
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.1rem;
  flex-shrink: 0;
}
.contact-label { font-size: 0.78rem; color: var(--text-muted); margin-bottom: 2px; }
.contact-value { font-size: 0.9rem; color: var(--text-main); font-weight: 500; }
.qr-row { display: flex; gap: 24px; flex-wrap: wrap; }
.qr-item { text-align: center; }
.qr-item img {
  width: 130px;
  height: 130px;
  object-fit: cover;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border);
}
.qr-label { font-size: 0.78rem; color: var(--text-muted); margin-top: 8px; }

/* ============================================================
   社交按钮
   ============================================================ */
.social-btn {
  padding: 8px 18px;
  border-radius: 50px;
  font-size: 0.82rem;
  font-weight: 600;
  background: rgba(124,58,237,0.12);
  border: 1px solid var(--border);
  color: var(--primary-light);
  transition: var(--transition);
}
.social-btn:hover {
  background: var(--primary);
  color: #fff;
  border-color: transparent;
}
.footer-social { display: flex; gap: 10px; flex-wrap: wrap; margin-top: 16px; }

/* ============================================================
   页脚
   ============================================================ */
.site-footer {
  background: rgba(13,8,32,0.98);
  border-top: 1px solid var(--border);
  padding: 60px 0 30px;
}
.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 40px;
  margin-bottom: 48px;
}
.footer-brand .site-logo { margin-bottom: 14px; }
.footer-brand p {
  font-size: 0.85rem;
  color: var(--text-muted);
  line-height: 1.7;
  margin-bottom: 4px;
}
.footer-col h4 {
  font-size: 0.95rem;
  font-weight: 700;
  color: var(--text-white);
  margin-bottom: 16px;
}
.footer-col ul li { margin-bottom: 10px; }
.footer-col ul a {
  font-size: 0.85rem;
  color: var(--text-muted);
  transition: var(--transition);
}
.footer-col ul a:hover { color: var(--primary-light); padding-left: 4px; }
.footer-bottom {
  border-top: 1px solid var(--border);
  padding-top: 24px;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  text-align: center;
}
.footer-bottom p { font-size: 0.82rem; color: var(--text-muted); }
.footer-bottom a { color: var(--text-muted); }
.footer-bottom a:hover { color: var(--primary-light); }
.footer-update {
  font-size: 0.82rem;
  color: var(--text-muted);
  background: rgba(124,58,237,0.1);
  border: 1px solid var(--border);
  padding: 4px 14px;
  border-radius: 50px;
}

/* ============================================================
   内页通用
   ============================================================ */
.inner-hero {
  padding: 80px 0 60px;
  text-align: center;
}
.inner-hero h1 {
  font-size: 2.4rem;
  font-weight: 800;
  color: var(--text-white);
  margin-bottom: 14px;
}
.inner-hero p {
  font-size: 1rem;
  color: var(--text-muted);
  max-width: 600px;
  margin: 0 auto;
}
.breadcrumb {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 0.82rem;
  color: var(--text-muted);
  padding: 12px 0;
}
.breadcrumb a { color: var(--text-muted); }
.breadcrumb a:hover { color: var(--primary-light); }
.breadcrumb .sep { color: var(--border); }
.breadcrumb .current { color: var(--primary-light); }
.page-content { padding: 60px 0; }
.sidebar { position: sticky; top: 88px; }
.sidebar-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 22px;
  margin-bottom: 20px;
}
.sidebar-card h4 {
  font-size: 0.95rem;
  font-weight: 700;
  color: var(--text-white);
  margin-bottom: 14px;
  padding-bottom: 10px;
  border-bottom: 1px solid var(--border);
}
.tag-cloud { display: flex; flex-wrap: wrap; gap: 8px; }
.tag-cloud a {
  background: rgba(124,58,237,0.1);
  border: 1px solid rgba(124,58,237,0.2);
  color: var(--primary-light);
  padding: 4px 12px;
  border-radius: 50px;
  font-size: 0.78rem;
  transition: var(--transition);
}
.tag-cloud a:hover { background: var(--primary); color: #fff; border-color: var(--primary); }

/* ============================================================
   弹幕效果（从右向左正确方向）
   ============================================================ */
.danmu-container {
  position: relative;
  overflow: hidden;
  height: 52px;
  background: rgba(0,0,0,0.25);
  border-radius: var(--radius-sm);
  margin: 16px 0 24px;
  border: 1px solid rgba(124,58,237,0.1);
}
.danmu-item {
  position: absolute;
  white-space: nowrap;
  font-size: 0.85rem;
  font-weight: 500;
  color: rgba(255,255,255,0.75);
  animation: danmuScroll linear infinite;
  /* 初始位置在右侧屏幕外 */
  left: 100%;
}
/* 弹幕从右向左滚动 */
@keyframes danmuScroll {
  from { transform: translateX(0); }
  to   { transform: translateX(calc(-100vw - 100%)); }
}

/* ============================================================
   动画
   ============================================================ */
@keyframes fadeInUp {
  from { opacity: 0; transform: translateY(24px); }
  to { opacity: 1; transform: translateY(0); }
}
.fade-in-up { animation: fadeInUp 0.6s ease forwards; }
.delay-1 { animation-delay: 0.1s; }
.delay-2 { animation-delay: 0.2s; }
.delay-3 { animation-delay: 0.3s; }

/* 默认可见，动画仅作为增强（避免JS未执行时内容空白） */
.animate-on-scroll {
  opacity: 1;
  transform: none;
}
/* 仅在JS成功接管并标记js-anim-ready后，才启用“先隐藏后渐入”效果 */
.js-anim-ready .animate-on-scroll {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}
.js-anim-ready .animate-on-scroll.fade-in-up {
  opacity: 1;
  transform: none;
}
@media (prefers-reduced-motion: reduce) {
  .js-anim-ready .animate-on-scroll {
    opacity: 1 !important;
    transform: none !important;
    transition: none !important;
  }
}

/* ============================================================
   懒加载骨架屏
   ============================================================ */
img[data-src] {
  background: linear-gradient(90deg, var(--bg-card) 25%, var(--bg-card2) 50%, var(--bg-card) 75%);
  background-size: 200% 100%;
  animation: shimmer 1.5s infinite;
}
@keyframes shimmer {
  0% { background-position: 200% 0; }
  100% { background-position: -200% 0; }
}

/* ============================================================
   返回顶部按钮
   ============================================================ */
.back-to-top {
  position: fixed;
  bottom: 28px;
  right: 24px;
  width: 44px;
  height: 44px;
  background: var(--gradient-main);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  color: #fff;
  box-shadow: 0 4px 20px rgba(124,58,237,0.4);
  opacity: 0;
  visibility: hidden;
  transform: translateY(10px);
  transition: var(--transition);
  z-index: 998;
}
.back-to-top.show {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}
.back-to-top:hover { transform: translateY(-3px); box-shadow: 0 8px 28px rgba(124,58,237,0.55); }

/* ============================================================
   响应式 - 平板 (≤1024px)
   ============================================================ */
@media (max-width: 1024px) {
  .footer-grid { grid-template-columns: 1fr 1fr; }
  .stats-bar { grid-template-columns: repeat(2, 1fr); }
  .contact-grid { grid-template-columns: 1fr; }
  .content-block { grid-template-columns: 1fr; gap: 32px; }
  .content-block.reverse { direction: ltr; }
}

/* ============================================================
   响应式 - 手机 (≤768px) - 百度移动端权重高，重点优化
   ============================================================ */
@media (max-width: 768px) {
  .section { padding: 56px 0; }
  .section-title { font-size: 1.7rem; }

  /* 导航：移动端折叠菜单 */
  .main-nav {
    display: none;
    position: fixed;
    top: var(--header-h);
    left: 0;
    right: 0;
    background: rgba(13,8,32,0.98);
    flex-direction: column;
    padding: 16px;
    border-bottom: 1px solid var(--border);
    z-index: 999;
    gap: 4px;
  }
  .main-nav.open { display: flex; }
  .main-nav a { padding: 12px 16px; border-radius: var(--radius-sm); font-size: 1rem; }
  .hamburger { display: flex; }

  /* 移动端搜索框：缩小但保留（百度移动端SEO重要） */
  .header-search {
    min-width: 0;
    max-width: 140px;
    padding: 5px 10px;
  }
  .header-search input { font-size: 0.82rem; }

  /* Hero */
  .hero { min-height: 420px; }
  .hero h1 { font-size: 1.9rem; }
  .hero p { font-size: 0.95rem; }
  .hero-stats { gap: 20px; }
  .hero-stats .stat-num { font-size: 1.3rem; }

  /* 网格 */
  .video-grid { grid-template-columns: repeat(2, 1fr); gap: 14px; }
  .experts-grid { grid-template-columns: repeat(2, 1fr); }
  .community-cards { grid-template-columns: repeat(2, 1fr); }
  .feature-grid { grid-template-columns: 1fr; }
  .howto-steps { grid-template-columns: 1fr; }

  /* 页脚 */
  .footer-grid { grid-template-columns: 1fr; gap: 28px; }
  .footer-bottom { flex-direction: column; text-align: center; }

  /* 联系 */
  .contact-grid { grid-template-columns: 1fr; }
}

/* ============================================================
   响应式 - 小屏手机 (≤480px)
   ============================================================ */
@media (max-width: 480px) {
  .section-title { font-size: 1.45rem; }
  .hero h1 { font-size: 1.55rem; }
  .hero-btns { flex-direction: column; align-items: flex-start; }
  .stats-bar { grid-template-columns: repeat(2, 1fr); padding: 20px 14px; }
  .stat-item .num { font-size: 1.5rem; }
  .video-grid { grid-template-columns: 1fr; }
  .experts-grid { grid-template-columns: 1fr; }
  .community-cards { grid-template-columns: 1fr; }
  .reviews-grid { grid-template-columns: 1fr; }
  .qr-row { justify-content: center; }
  .filter-bar { gap: 8px; }
  .filter-btn { padding: 6px 14px; font-size: 0.82rem; }

  /* 移动端搜索框：极小屏只显示图标 */
  .header-search { min-width: 36px; max-width: 36px; padding: 6px; }
  .header-search input { display: none; }
}