/* ============================================
   四虎 - 汽车改装视频社区 原创样式表
   品牌：四虎 | 域名：niuniu99.com.cn
   配色方案：深邃暗夜 + 活力橙 + 科技青绿
   ============================================ */

/* === CSS变量定义 === */
:root {
  --kkt-primary: #1A1F35;
  --kkt-accent: #FF6B35;
  --kkt-teal: #00D4AA;
  --kkt-bg: #0D1117;
  --kkt-card: #161B28;
  --kkt-card-hover: #1E2538;
  --kkt-text: #E8ECF1;
  --kkt-text-secondary: #8B95A5;
  --kkt-border: #2A3045;
  --kkt-gradient-start: #FF6B35;
  --kkt-gradient-end: #00D4AA;
  --kkt-shadow: rgba(0, 0, 0, 0.35);
  --kkt-radius: 12px;
  --kkt-radius-sm: 8px;
  --kkt-transition: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  --kkt-max-width: 1280px;
  --kkt-font: 'PingFang SC', 'Microsoft YaHei', 'Helvetica Neue', Arial, sans-serif;
}

/* === 基础重置 === */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; font-size: 16px; }
body {
  font-family: var(--kkt-font);
  background-color: var(--kkt-bg);
  color: var(--kkt-text);
  line-height: 1.7;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}
a { color: var(--kkt-accent); text-decoration: none; transition: color var(--kkt-transition); }
a:hover { color: var(--kkt-teal); }
img { max-width: 100%; height: auto; display: block; }
ul, ol { list-style: none; }
h1, h2, h3, h4, h5, h6 { font-weight: 700; line-height: 1.3; color: var(--kkt-text); }

/* === 容器 === */
.kkt-container { max-width: var(--kkt-max-width); margin: 0 auto; padding: 0 20px; }
.kkt-section { padding: 70px 0; }
.kkt-section-alt { background-color: var(--kkt-primary); }

/* === 标题样式 === */
.kkt-section-title {
  text-align: center;
  margin-bottom: 50px;
}
.kkt-section-title h2 {
  font-size: 2rem;
  margin-bottom: 12px;
  background: linear-gradient(135deg, var(--kkt-accent), var(--kkt-teal));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}
.kkt-section-title p {
  color: var(--kkt-text-secondary);
  font-size: 1rem;
  max-width: 600px;
  margin: 0 auto;
}

/* === 顶部导航 === */
.kkt-header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  z-index: 1000;
  background: rgba(13, 17, 23, 0.92);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--kkt-border);
  transition: background var(--kkt-transition);
}
.kkt-header-inner {
  max-width: var(--kkt-max-width);
  margin: 0 auto;
  padding: 0 20px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 68px;
}
.kkt-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 1.35rem;
  font-weight: 800;
  color: var(--kkt-text);
}
.kkt-logo img { height: 40px; width: 40px; border-radius: 8px; }
.kkt-logo span { background: linear-gradient(135deg, var(--kkt-accent), var(--kkt-teal)); -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text; }

.kkt-nav { display: flex; align-items: center; gap: 6px; }
.kkt-nav a {
  color: var(--kkt-text-secondary);
  font-size: 0.9rem;
  padding: 8px 14px;
  border-radius: var(--kkt-radius-sm);
  transition: all var(--kkt-transition);
  white-space: nowrap;
}
.kkt-nav a:hover, .kkt-nav a.active {
  color: var(--kkt-text);
  background: rgba(255, 107, 53, 0.12);
}

.kkt-menu-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  cursor: pointer;
  padding: 8px;
}
.kkt-menu-toggle span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--kkt-text);
  border-radius: 2px;
  transition: all var(--kkt-transition);
}

/* === 搜索框 === */
.kkt-search-bar {
  background: var(--kkt-primary);
  padding: 14px 0;
  margin-top: 68px;
  border-bottom: 1px solid var(--kkt-border);
}
.kkt-search-wrap {
  max-width: 640px;
  margin: 0 auto;
  position: relative;
  padding: 0 20px;
}
.kkt-search-wrap input {
  width: 100%;
  padding: 12px 50px 12px 20px;
  border: 2px solid var(--kkt-border);
  border-radius: 50px;
  background: var(--kkt-card);
  color: var(--kkt-text);
  font-size: 0.95rem;
  outline: none;
  transition: border-color var(--kkt-transition);
  font-family: var(--kkt-font);
}
.kkt-search-wrap input:focus { border-color: var(--kkt-accent); }
.kkt-search-wrap input::placeholder { color: var(--kkt-text-secondary); }
.kkt-search-btn {
  position: absolute;
  right: 28px;
  top: 50%;
  transform: translateY(-50%);
  background: var(--kkt-accent);
  border: none;
  color: #fff;
  width: 36px;
  height: 36px;
  border-radius: 50%;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1rem;
  transition: background var(--kkt-transition);
}
.kkt-search-btn:hover { background: var(--kkt-teal); }

/* === Hero横幅 === */
.kkt-hero {
  position: relative;
  height: 520px;
  overflow: hidden;
  display: flex;
  align-items: center;
  justify-content: center;
}
.kkt-hero-bg {
  position: absolute;
  inset: 0;
  background-size: cover;
  background-position: center;
  filter: brightness(0.45);
}
.kkt-hero-content {
  position: relative;
  z-index: 2;
  text-align: center;
  padding: 0 20px;
}
.kkt-hero h1 {
  font-size: 2.8rem;
  margin-bottom: 16px;
  text-shadow: 0 4px 20px rgba(0,0,0,0.5);
}
.kkt-hero h1 em {
  font-style: normal;
  background: linear-gradient(135deg, var(--kkt-accent), var(--kkt-teal));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}
.kkt-hero p {
  font-size: 1.15rem;
  color: var(--kkt-text-secondary);
  max-width: 600px;
  margin: 0 auto 28px;
}
.kkt-hero-btns { display: flex; gap: 16px; justify-content: center; flex-wrap: wrap; }

/* === 按钮 === */
.kkt-btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 12px 28px;
  border-radius: 50px;
  font-size: 0.95rem;
  font-weight: 600;
  cursor: pointer;
  border: none;
  transition: all var(--kkt-transition);
  font-family: var(--kkt-font);
}
.kkt-btn-primary {
  background: linear-gradient(135deg, var(--kkt-accent), #FF8F5E);
  color: #fff;
  box-shadow: 0 4px 20px rgba(255, 107, 53, 0.35);
}
.kkt-btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 30px rgba(255, 107, 53, 0.5);
  color: #fff;
}
.kkt-btn-outline {
  background: transparent;
  color: var(--kkt-teal);
  border: 2px solid var(--kkt-teal);
}
.kkt-btn-outline:hover {
  background: var(--kkt-teal);
  color: var(--kkt-bg);
}

/* === 视频卡片网格 === */
.kkt-video-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 24px;
}
.kkt-video-card {
  background: var(--kkt-card);
  border-radius: var(--kkt-radius);
  overflow: hidden;
  border: 1px solid var(--kkt-border);
  transition: all var(--kkt-transition);
  cursor: pointer;
}
.kkt-video-card:hover {
  transform: translateY(-6px);
  border-color: var(--kkt-accent);
  box-shadow: 0 12px 40px var(--kkt-shadow);
}
.kkt-video-thumb {
  position: relative;
  aspect-ratio: 16/9;
  overflow: hidden;
}
.kkt-video-thumb img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform var(--kkt-transition);
}
.kkt-video-card:hover .kkt-video-thumb img { transform: scale(1.06); }
.kkt-video-play {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(0,0,0,0.35);
  opacity: 0;
  transition: opacity var(--kkt-transition);
}
.kkt-video-card:hover .kkt-video-play { opacity: 1; }
.kkt-video-play-icon {
  width: 60px;
  height: 60px;
  background: rgba(255, 107, 53, 0.9);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: transform var(--kkt-transition);
}
.kkt-video-play-icon::after {
  content: '';
  display: block;
  width: 0;
  height: 0;
  border-style: solid;
  border-width: 10px 0 10px 18px;
  border-color: transparent transparent transparent #fff;
  margin-left: 4px;
}
.kkt-video-card:hover .kkt-video-play-icon { transform: scale(1.1); }
.kkt-video-duration {
  position: absolute;
  bottom: 8px;
  right: 8px;
  background: rgba(0,0,0,0.78);
  color: #fff;
  padding: 2px 8px;
  border-radius: 4px;
  font-size: 0.78rem;
  font-weight: 600;
}
.kkt-video-info { padding: 16px; }
.kkt-video-info h3 {
  font-size: 1rem;
  margin-bottom: 8px;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}
.kkt-video-meta {
  display: flex;
  align-items: center;
  gap: 16px;
  color: var(--kkt-text-secondary);
  font-size: 0.82rem;
}
.kkt-video-meta span { display: flex; align-items: center; gap: 4px; }
.kkt-video-tag {
  display: inline-block;
  background: rgba(255, 107, 53, 0.12);
  color: var(--kkt-accent);
  padding: 2px 10px;
  border-radius: 20px;
  font-size: 0.75rem;
  margin-top: 8px;
}

/* === 模块卡片 === */
.kkt-module-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 20px;
}
.kkt-module-card {
  background: var(--kkt-card);
  border: 1px solid var(--kkt-border);
  border-radius: var(--kkt-radius);
  padding: 28px 24px;
  text-align: center;
  transition: all var(--kkt-transition);
}
.kkt-module-card:hover {
  transform: translateY(-4px);
  border-color: var(--kkt-teal);
  box-shadow: 0 8px 30px rgba(0, 212, 170, 0.15);
}
.kkt-module-icon {
  width: 56px;
  height: 56px;
  margin: 0 auto 16px;
  background: linear-gradient(135deg, var(--kkt-accent), var(--kkt-teal));
  border-radius: 14px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
}
.kkt-module-card h3 { font-size: 1.1rem; margin-bottom: 8px; }
.kkt-module-card p { color: var(--kkt-text-secondary); font-size: 0.88rem; }

/* === 专家展示 === */
.kkt-expert-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 24px;
}
.kkt-expert-card {
  background: var(--kkt-card);
  border: 1px solid var(--kkt-border);
  border-radius: var(--kkt-radius);
  overflow: hidden;
  transition: all var(--kkt-transition);
}
.kkt-expert-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 8px 30px var(--kkt-shadow);
}
.kkt-expert-photo {
  height: 220px;
  overflow: hidden;
}
.kkt-expert-photo img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: top;
  transition: transform var(--kkt-transition);
}
.kkt-expert-card:hover .kkt-expert-photo img { transform: scale(1.05); }
.kkt-expert-info { padding: 20px; }
.kkt-expert-info h3 { font-size: 1.1rem; margin-bottom: 4px; }
.kkt-expert-role {
  color: var(--kkt-accent);
  font-size: 0.85rem;
  font-weight: 600;
  margin-bottom: 10px;
}
.kkt-expert-info p { color: var(--kkt-text-secondary); font-size: 0.85rem; margin-bottom: 14px; }
.kkt-expert-btns { display: flex; gap: 10px; }
.kkt-expert-btns a {
  padding: 6px 16px;
  border-radius: 20px;
  font-size: 0.8rem;
  font-weight: 600;
  border: 1px solid var(--kkt-border);
  color: var(--kkt-text-secondary);
  transition: all var(--kkt-transition);
}
.kkt-expert-btns a:hover { border-color: var(--kkt-accent); color: var(--kkt-accent); }

/* === 合作品牌Logo墙 === */
.kkt-brand-wall {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 30px;
  padding: 20px 0;
}
.kkt-brand-item {
  width: 120px;
  height: 60px;
  background: var(--kkt-card);
  border: 1px solid var(--kkt-border);
  border-radius: var(--kkt-radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  color: var(--kkt-text-secondary);
  font-size: 0.85rem;
  transition: all var(--kkt-transition);
}
.kkt-brand-item:hover { border-color: var(--kkt-accent); color: var(--kkt-accent); }

/* === FAQ === */
.kkt-faq-list { max-width: 800px; margin: 0 auto; }
.kkt-faq-item {
  background: var(--kkt-card);
  border: 1px solid var(--kkt-border);
  border-radius: var(--kkt-radius);
  margin-bottom: 12px;
  overflow: hidden;
}
.kkt-faq-q {
  padding: 18px 24px;
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-weight: 600;
  font-size: 0.95rem;
  transition: background var(--kkt-transition);
}
.kkt-faq-q:hover { background: var(--kkt-card-hover); }
.kkt-faq-q::after {
  content: '+';
  font-size: 1.3rem;
  color: var(--kkt-accent);
  transition: transform var(--kkt-transition);
  flex-shrink: 0;
  margin-left: 12px;
}
.kkt-faq-item.open .kkt-faq-q::after { content: '-'; }
.kkt-faq-a {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.4s ease, padding 0.4s ease;
}
.kkt-faq-item.open .kkt-faq-a { max-height: 300px; }
.kkt-faq-a-inner {
  padding: 0 24px 18px;
  color: var(--kkt-text-secondary);
  font-size: 0.9rem;
  line-height: 1.8;
}

/* === 用户评论 === */
.kkt-review-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 20px;
}
.kkt-review-card {
  background: var(--kkt-card);
  border: 1px solid var(--kkt-border);
  border-radius: var(--kkt-radius);
  padding: 24px;
  transition: all var(--kkt-transition);
}
.kkt-review-card:hover { border-color: var(--kkt-teal); }
.kkt-review-stars { color: var(--kkt-accent); font-size: 0.9rem; margin-bottom: 10px; letter-spacing: 2px; }
.kkt-review-text { color: var(--kkt-text-secondary); font-size: 0.9rem; margin-bottom: 14px; line-height: 1.7; }
.kkt-review-author { font-weight: 600; font-size: 0.85rem; }
.kkt-review-date { color: var(--kkt-text-secondary); font-size: 0.78rem; }

/* === 联系信息 === */
.kkt-contact-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 24px;
}
.kkt-contact-card {
  background: var(--kkt-card);
  border: 1px solid var(--kkt-border);
  border-radius: var(--kkt-radius);
  padding: 28px;
}
.kkt-contact-card h3 {
  font-size: 1.1rem;
  margin-bottom: 16px;
  color: var(--kkt-accent);
}
.kkt-contact-item {
  display: flex;
  align-items: flex-start;
  gap: 12px;
  margin-bottom: 12px;
  color: var(--kkt-text-secondary);
  font-size: 0.9rem;
}
.kkt-contact-item strong { color: var(--kkt-text); min-width: 70px; }

/* === How-To指南 === */
.kkt-howto-steps {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
  gap: 20px;
  counter-reset: step;
}
.kkt-howto-step {
  background: var(--kkt-card);
  border: 1px solid var(--kkt-border);
  border-radius: var(--kkt-radius);
  padding: 28px 24px;
  position: relative;
  counter-increment: step;
}
.kkt-howto-step::before {
  content: counter(step);
  position: absolute;
  top: -14px;
  left: 24px;
  width: 32px;
  height: 32px;
  background: linear-gradient(135deg, var(--kkt-accent), var(--kkt-teal));
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 0.85rem;
  color: #fff;
}
.kkt-howto-step h4 { margin-bottom: 8px; font-size: 1rem; }
.kkt-howto-step p { color: var(--kkt-text-secondary); font-size: 0.85rem; }

/* === 页脚 === */
.kkt-footer {
  background: var(--kkt-primary);
  border-top: 1px solid var(--kkt-border);
  padding: 50px 0 30px;
}
.kkt-footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 40px;
  margin-bottom: 40px;
}
.kkt-footer-brand .kkt-logo { margin-bottom: 14px; }
.kkt-footer-brand p { color: var(--kkt-text-secondary); font-size: 0.88rem; max-width: 320px; }
.kkt-footer-col h4 {
  font-size: 1rem;
  margin-bottom: 16px;
  color: var(--kkt-text);
}
.kkt-footer-col a {
  display: block;
  color: var(--kkt-text-secondary);
  font-size: 0.88rem;
  padding: 4px 0;
  transition: color var(--kkt-transition);
}
.kkt-footer-col a:hover { color: var(--kkt-accent); }
.kkt-footer-qr {
  display: flex;
  gap: 20px;
  margin-top: 20px;
}
.kkt-footer-qr-item { text-align: center; }
.kkt-footer-qr-item img { width: 100px; height: 100px; border-radius: 8px; margin-bottom: 6px; }
.kkt-footer-qr-item span { font-size: 0.78rem; color: var(--kkt-text-secondary); }
.kkt-footer-bottom {
  border-top: 1px solid var(--kkt-border);
  padding-top: 24px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 12px;
}
.kkt-footer-copy { color: var(--kkt-text-secondary); font-size: 0.82rem; }
.kkt-footer-social { display: flex; gap: 12px; }
.kkt-footer-social a {
  width: 36px;
  height: 36px;
  background: var(--kkt-card);
  border: 1px solid var(--kkt-border);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--kkt-text-secondary);
  font-size: 0.85rem;
  transition: all var(--kkt-transition);
}
.kkt-footer-social a:hover { border-color: var(--kkt-accent); color: var(--kkt-accent); background: rgba(255,107,53,0.1); }

/* === 分享按钮 === */
.kkt-share-bar {
  position: fixed;
  right: 20px;
  top: 50%;
  transform: translateY(-50%);
  z-index: 999;
  display: flex;
  flex-direction: column;
  gap: 8px;
}
.kkt-share-btn {
  width: 42px;
  height: 42px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.9rem;
  color: #fff;
  cursor: pointer;
  transition: all var(--kkt-transition);
  border: none;
}
.kkt-share-btn:hover { transform: scale(1.15); }
.kkt-share-wechat { background: #07C160; }
.kkt-share-weibo { background: #E6162D; }
.kkt-share-douyin { background: #161823; border: 1px solid #333; }
.kkt-share-bilibili { background: #FB7299; }

/* === 面包屑 === */
.kkt-breadcrumb {
  max-width: var(--kkt-max-width);
  margin: 0 auto;
  padding: 16px 20px;
  font-size: 0.85rem;
  color: var(--kkt-text-secondary);
}
.kkt-breadcrumb ol {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 0;
  list-style: none;
  margin: 0;
  padding: 0;
}
.kkt-breadcrumb li::after {
  content: '/';
  margin: 0 8px;
  color: var(--kkt-text-secondary);
}
.kkt-breadcrumb li:last-child::after { display: none; }
.kkt-breadcrumb li:last-child { font-weight: 600; color: var(--kkt-text); }
.kkt-breadcrumb a { color: var(--kkt-text-secondary); }
.kkt-breadcrumb a:hover { color: var(--kkt-accent); }
.kkt-breadcrumb span { margin: 0; }

/* === 标签云 === */
.kkt-tags { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 16px; }
.kkt-tag {
  background: rgba(255, 107, 53, 0.1);
  color: var(--kkt-accent);
  padding: 4px 14px;
  border-radius: 20px;
  font-size: 0.8rem;
  transition: all var(--kkt-transition);
}
.kkt-tag:hover { background: var(--kkt-accent); color: #fff; }

/* === 数据统计 === */
.kkt-stats {
  display: flex;
  justify-content: center;
  gap: 50px;
  padding: 40px 0;
  flex-wrap: wrap;
}
.kkt-stat { text-align: center; }
.kkt-stat-num {
  font-size: 2.2rem;
  font-weight: 800;
  background: linear-gradient(135deg, var(--kkt-accent), var(--kkt-teal));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}
.kkt-stat-label { color: var(--kkt-text-secondary); font-size: 0.88rem; margin-top: 4px; }

/* === MCP前端代码区 === */
.kkt-mcp-section {
  background: var(--kkt-card);
  border: 1px solid var(--kkt-border);
  border-radius: var(--kkt-radius);
  padding: 24px;
  margin-top: 30px;
}
.kkt-mcp-section h4 { color: var(--kkt-teal); margin-bottom: 12px; }
.kkt-mcp-code {
  background: var(--kkt-bg);
  border-radius: var(--kkt-radius-sm);
  padding: 16px;
  font-family: 'Courier New', monospace;
  font-size: 0.82rem;
  color: var(--kkt-teal);
  overflow-x: auto;
  line-height: 1.6;
}

/* === 回到顶部 === */
.kkt-back-top {
  position: fixed;
  bottom: 30px;
  right: 20px;
  width: 44px;
  height: 44px;
  background: var(--kkt-accent);
  color: #fff;
  border: none;
  border-radius: 50%;
  cursor: pointer;
  font-size: 1.2rem;
  display: none;
  align-items: center;
  justify-content: center;
  z-index: 998;
  transition: all var(--kkt-transition);
  box-shadow: 0 4px 16px rgba(255,107,53,0.4);
}
.kkt-back-top:hover { transform: translateY(-3px); }
.kkt-back-top.show { display: flex; }

/* === 内页样式 === */
.kkt-page-hero {
  height: 300px;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  position: relative;
  overflow: hidden;
}
.kkt-page-hero-bg {
  position: absolute;
  inset: 0;
  background-size: cover;
  background-position: center;
  filter: brightness(0.35);
}
.kkt-page-hero-content { position: relative; z-index: 2; }
.kkt-page-hero h1 { font-size: 2.2rem; margin-bottom: 8px; }
.kkt-page-hero p { color: var(--kkt-text-secondary); font-size: 1rem; }

/* === 响应式 === */
@media (max-width: 1024px) {
  .kkt-footer-grid { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 768px) {
  .kkt-menu-toggle { display: flex; }
  .kkt-nav {
    display: none;
    position: absolute;
    top: 68px;
    left: 0;
    width: 100%;
    background: rgba(13, 17, 23, 0.98);
    flex-direction: column;
    padding: 16px;
    border-bottom: 1px solid var(--kkt-border);
  }
  .kkt-nav.open { display: flex; }
  .kkt-nav a { padding: 12px 16px; width: 100%; }
  .kkt-hero { height: 400px; }
  .kkt-hero h1 { font-size: 1.8rem; }
  .kkt-section { padding: 50px 0; }
  .kkt-section-title h2 { font-size: 1.6rem; }
  .kkt-video-grid { grid-template-columns: 1fr; }
  .kkt-module-grid { grid-template-columns: 1fr; }
  .kkt-expert-grid { grid-template-columns: 1fr; }
  .kkt-footer-grid { grid-template-columns: 1fr; }
  .kkt-footer-bottom { flex-direction: column; text-align: center; }
  .kkt-stats { gap: 30px; }
  .kkt-stat-num { font-size: 1.6rem; }
  .kkt-share-bar { display: none; }
  .kkt-contact-grid { grid-template-columns: 1fr; }
  .kkt-howto-steps { grid-template-columns: 1fr; }
  .kkt-page-hero { height: 220px; }
  .kkt-page-hero h1 { font-size: 1.6rem; }
}
@media (max-width: 480px) {
  .kkt-hero h1 { font-size: 1.5rem; }
  .kkt-hero p { font-size: 0.95rem; }
  .kkt-btn { padding: 10px 22px; font-size: 0.88rem; }
  .kkt-video-grid { grid-template-columns: 1fr; }
  .kkt-review-grid { grid-template-columns: 1fr; }
}

/* === 懒加载占位 === */
.kkt-lazy {
  opacity: 0;
  transition: opacity 0.6s ease;
}
.kkt-lazy.loaded { opacity: 1; }

/* === 动画 === */
@keyframes kktFadeUp {
  from { opacity: 0; transform: translateY(30px); }
  to { opacity: 1; transform: translateY(0); }
}
.kkt-animate { animation: kktFadeUp 0.6s ease forwards; }