/* =============================================
   51吃瓜 - 暗黑潮流·霓虹金紫渐变风格
   全局样式 | 响应式 | 赛博朋克科技娱乐
   ============================================= */

/* ---------- CSS变量 ---------- */
:root {
  --bg-primary: #0a0a0f;
  --bg-secondary: #0f0f1a;
  --bg-card: #13131f;
  --bg-card-hover: #1a1a2e;
  --neon-gold: #f0b429;
  --neon-purple: #9b59b6;
  --neon-purple-bright: #c77dff;
  --neon-pink: #e040fb;
  --text-primary: #f0f0f5;
  --text-secondary: #a0a0b5;
  --text-muted: #606078;
  --border-color: rgba(155, 89, 182, 0.25);
  --border-gold: rgba(240, 180, 41, 0.3);
  --gradient-gold-purple: linear-gradient(135deg, #f0b429 0%, #9b59b6 50%, #c77dff 100%);
  --gradient-dark: linear-gradient(180deg, #0a0a0f 0%, #0f0f1a 100%);
  --shadow-neon-purple: 0 0 20px rgba(155, 89, 182, 0.4), 0 0 40px rgba(155, 89, 182, 0.2);
  --shadow-neon-gold: 0 0 20px rgba(240, 180, 41, 0.4), 0 0 40px rgba(240, 180, 41, 0.2);
  --font-main: 'PingFang SC', 'Microsoft YaHei', 'Hiragino Sans GB', sans-serif;
  --radius-sm: 6px;
  --radius-md: 12px;
  --radius-lg: 20px;
  --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

/* ---------- 重置与基础 ---------- */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
  font-size: 16px;
}

body {
  background-color: var(--bg-primary);
  color: var(--text-primary);
  font-family: var(--font-main);
  line-height: 1.7;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}

a {
  color: var(--neon-gold);
  text-decoration: none;
  transition: var(--transition);
}

a:hover {
  color: var(--neon-purple-bright);
}

img {
  max-width: 100%;
  height: auto;
  display: block;
}

ul, ol {
  list-style: none;
}

/* ---------- 粒子背景 ---------- */
#particles-canvas {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
  z-index: 0;
  opacity: 0.4;
}

/* ---------- 容器 ---------- */
.container {
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 24px;
}

.section {
  padding: 80px 0;
  position: relative;
  z-index: 1;
}

/* ---------- 导航栏 ---------- */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  z-index: 1000;
  background: rgba(10, 10, 15, 0.92);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--border-color);
  transition: var(--transition);
}

.navbar.scrolled {
  background: rgba(10, 10, 15, 0.98);
  box-shadow: 0 4px 30px rgba(155, 89, 182, 0.15);
}

.navbar-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 68px;
  padding: 0 24px;
  max-width: 1280px;
  margin: 0 auto;
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 1.5rem;
  font-weight: 900;
  letter-spacing: 0.05em;
  background: var(--gradient-gold-purple);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.logo-icon {
  width: 38px;
  height: 38px;
  background: var(--gradient-gold-purple);
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.1rem;
  font-weight: 900;
  color: #0a0a0f;
  -webkit-text-fill-color: #0a0a0f;
  flex-shrink: 0;
  box-shadow: var(--shadow-neon-gold);
}

.nav-menu {
  display: flex;
  align-items: center;
  gap: 4px;
}

.nav-link {
  color: var(--text-secondary);
  font-size: 0.9rem;
  font-weight: 500;
  padding: 8px 14px;
  border-radius: var(--radius-sm);
  transition: var(--transition);
  white-space: nowrap;
  position: relative;
}

.nav-link::after {
  content: '';
  position: absolute;
  bottom: 4px;
  left: 50%;
  transform: translateX(-50%);
  width: 0;
  height: 2px;
  background: var(--gradient-gold-purple);
  border-radius: 2px;
  transition: var(--transition);
}

.nav-link:hover,
.nav-link.active {
  color: var(--neon-gold);
  background: rgba(240, 180, 41, 0.08);
}

.nav-link:hover::after,
.nav-link.active::after {
  width: 60%;
}

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  cursor: pointer;
  padding: 8px;
  background: none;
  border: none;
}

.nav-toggle span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--neon-gold);
  border-radius: 2px;
  transition: var(--transition);
}

/* ---------- 搜索框 ---------- */
.search-bar-wrap {
  background: rgba(15, 15, 26, 0.95);
  border-bottom: 1px solid var(--border-gold);
  padding: 12px 0;
  position: sticky;
  top: 68px;
  z-index: 999;
}

.search-bar-inner {
  max-width: 700px;
  margin: 0 auto;
  padding: 0 24px;
  display: flex;
  align-items: center;
  gap: 10px;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 50px;
  padding: 10px 20px;
  transition: var(--transition);
}

.search-bar-inner:focus-within {
  border-color: var(--neon-gold);
  box-shadow: 0 0 15px rgba(240, 180, 41, 0.2);
}

.search-icon {
  color: var(--text-muted);
  font-size: 1rem;
  flex-shrink: 0;
}

.search-input {
  flex: 1;
  background: none;
  border: none;
  outline: none;
  color: var(--text-primary);
  font-size: 0.95rem;
  font-family: var(--font-main);
}

.search-input::placeholder {
  color: var(--text-muted);
}

.search-btn {
  background: var(--gradient-gold-purple);
  border: none;
  color: #0a0a0f;
  font-weight: 700;
  font-size: 0.85rem;
  padding: 6px 18px;
  border-radius: 50px;
  cursor: pointer;
  transition: var(--transition);
  white-space: nowrap;
  font-family: var(--font-main);
}

.search-btn:hover {
  transform: scale(1.05);
  box-shadow: var(--shadow-neon-gold);
}

/* ---------- 首屏Banner ---------- */
.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  overflow: hidden;
  padding-top: 120px;
}

.hero-bg {
  position: absolute;
  inset: 0;
  z-index: 0;
}

.hero-bg img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  opacity: 0.35;
}

.hero-bg::after {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(180deg, rgba(10,10,15,0.3) 0%, rgba(10,10,15,0.7) 60%, rgba(10,10,15,1) 100%);
}

.hero-content {
  position: relative;
  z-index: 2;
  text-align: center;
  max-width: 900px;
  padding: 0 24px;
}

.hero-badge {
  display: inline-block;
  background: rgba(240, 180, 41, 0.12);
  border: 1px solid var(--border-gold);
  color: var(--neon-gold);
  font-size: 0.8rem;
  font-weight: 600;
  padding: 6px 18px;
  border-radius: 50px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  margin-bottom: 24px;
  animation: pulse-glow 2s infinite;
}

@keyframes pulse-glow {
  0%, 100% { box-shadow: 0 0 10px rgba(240, 180, 41, 0.2); }
  50% { box-shadow: 0 0 25px rgba(240, 180, 41, 0.5); }
}

.hero-title {
  font-size: clamp(2.5rem, 6vw, 5rem);
  font-weight: 900;
  line-height: 1.15;
  margin-bottom: 20px;
  background: var(--gradient-gold-purple);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  text-shadow: none;
}

.hero-subtitle {
  font-size: clamp(1rem, 2vw, 1.3rem);
  color: var(--text-secondary);
  margin-bottom: 40px;
  max-width: 600px;
  margin-left: auto;
  margin-right: auto;
}

.hero-btns {
  display: flex;
  gap: 16px;
  justify-content: center;
  flex-wrap: wrap;
}

.btn-primary {
  background: var(--gradient-gold-purple);
  color: #0a0a0f;
  font-weight: 800;
  font-size: 1rem;
  padding: 14px 36px;
  border-radius: 50px;
  border: none;
  cursor: pointer;
  transition: var(--transition);
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-main);
  text-decoration: none;
}

.btn-primary:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-neon-gold);
  color: #0a0a0f;
}

.btn-outline {
  background: transparent;
  color: var(--neon-purple-bright);
  font-weight: 700;
  font-size: 1rem;
  padding: 13px 36px;
  border-radius: 50px;
  border: 1.5px solid var(--neon-purple-bright);
  cursor: pointer;
  transition: var(--transition);
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-main);
  text-decoration: none;
}

.btn-outline:hover {
  background: rgba(155, 89, 182, 0.15);
  box-shadow: var(--shadow-neon-purple);
  color: var(--neon-purple-bright);
  transform: translateY(-3px);
}

.hero-stats {
  display: flex;
  gap: 40px;
  justify-content: center;
  margin-top: 60px;
  flex-wrap: wrap;
}

.stat-item {
  text-align: center;
}

.stat-num {
  font-size: 2rem;
  font-weight: 900;
  background: var(--gradient-gold-purple);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  display: block;
}

.stat-label {
  font-size: 0.8rem;
  color: var(--text-muted);
  margin-top: 4px;
}

/* ---------- 区块标题 ---------- */
.section-header {
  text-align: center;
  margin-bottom: 56px;
}

.section-tag {
  display: inline-block;
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--neon-gold);
  background: rgba(240, 180, 41, 0.1);
  border: 1px solid var(--border-gold);
  padding: 4px 14px;
  border-radius: 50px;
  margin-bottom: 14px;
}

.section-title {
  font-size: clamp(1.8rem, 3.5vw, 2.8rem);
  font-weight: 900;
  color: var(--text-primary);
  margin-bottom: 14px;
  line-height: 1.25;
}

.section-title span {
  background: var(--gradient-gold-purple);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.section-desc {
  color: var(--text-secondary);
  font-size: 1rem;
  max-width: 560px;
  margin: 0 auto;
}

/* ---------- 视频卡片 ---------- */
.video-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 24px;
}

.video-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  overflow: hidden;
  transition: var(--transition);
  cursor: pointer;
  position: relative;
}

.video-card:hover {
  transform: translateY(-6px);
  border-color: var(--neon-purple);
  box-shadow: var(--shadow-neon-purple);
}

.video-thumb {
  position: relative;
  aspect-ratio: 16/9;
  overflow: hidden;
  background: var(--bg-secondary);
}

.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);
}

.video-play-btn {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(0, 0, 0, 0);
  transition: var(--transition);
  opacity: 0;
}

.video-card:hover .video-play-btn {
  opacity: 1;
  background: rgba(0, 0, 0, 0.45);
}

.play-circle {
  width: 64px;
  height: 64px;
  background: var(--gradient-gold-purple);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
  color: #0a0a0f;
  box-shadow: 0 0 30px rgba(240, 180, 41, 0.6);
  transform: scale(0.8);
  transition: transform 0.3s ease;
}

.video-card:hover .play-circle {
  transform: scale(1);
}

.video-duration {
  position: absolute;
  bottom: 8px;
  right: 8px;
  background: rgba(0,0,0,0.75);
  color: #fff;
  font-size: 0.75rem;
  padding: 2px 8px;
  border-radius: 4px;
  font-weight: 600;
}

.video-tag {
  position: absolute;
  top: 8px;
  left: 8px;
  background: var(--gradient-gold-purple);
  color: #0a0a0f;
  font-size: 0.7rem;
  font-weight: 700;
  padding: 3px 10px;
  border-radius: 4px;
}

.video-info {
  padding: 16px;
}

.video-title {
  font-size: 0.95rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 10px;
  line-height: 1.4;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.video-meta {
  display: flex;
  gap: 14px;
  font-size: 0.78rem;
  color: var(--text-muted);
}

.video-meta span {
  display: flex;
  align-items: center;
  gap: 4px;
}

/* ---------- 社区模块 ---------- */
.community-section {
  background: var(--bg-secondary);
}

.community-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 32px;
  align-items: start;
}

.community-topics {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.topic-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 20px;
  transition: var(--transition);
  cursor: pointer;
}

.topic-card:hover {
  border-color: var(--neon-gold);
  box-shadow: var(--shadow-neon-gold);
  transform: translateX(6px);
}

.topic-tag {
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--neon-gold);
  margin-bottom: 6px;
}

.topic-desc {
  font-size: 0.9rem;
  color: var(--text-secondary);
}

.topic-stats {
  display: flex;
  gap: 12px;
  margin-top: 10px;
  font-size: 0.75rem;
  color: var(--text-muted);
}

.danmu-box {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 24px;
  overflow: hidden;
  min-height: 320px;
  position: relative;
}

.danmu-title {
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--neon-purple-bright);
  margin-bottom: 16px;
  display: flex;
  align-items: center;
  gap: 8px;
}

.danmu-live {
  display: inline-block;
  width: 8px;
  height: 8px;
  background: #ff4444;
  border-radius: 50%;
  animation: blink 1s infinite;
}

@keyframes blink {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.2; }
}

.danmu-stream {
  display: flex;
  flex-direction: column;
  gap: 10px;
  max-height: 260px;
  overflow: hidden;
}

.danmu-item {
  font-size: 0.85rem;
  color: var(--text-secondary);
  padding: 8px 12px;
  background: rgba(155, 89, 182, 0.08);
  border-left: 2px solid var(--neon-purple);
  border-radius: 0 6px 6px 0;
  animation: slideIn 0.4s ease;
}

@keyframes slideIn {
  from { opacity: 0; transform: translateX(-10px); }
  to { opacity: 1; transform: translateX(0); }
}

.danmu-item .user {
  color: var(--neon-gold);
  font-weight: 600;
  margin-right: 6px;
}

/* ---------- AI模块 ---------- */
.ai-section {
  background: var(--bg-primary);
}

.ai-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 48px;
  align-items: center;
}

.ai-img-wrap {
  border-radius: var(--radius-lg);
  overflow: hidden;
  position: relative;
  box-shadow: var(--shadow-neon-purple);
}

.ai-img-wrap img {
  width: 100%;
  height: auto;
}

.ai-img-wrap::after {
  content: '';
  position: absolute;
  inset: 0;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  pointer-events: none;
}

.ai-tools {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
  margin-top: 32px;
}

.ai-tool-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 18px;
  transition: var(--transition);
}

.ai-tool-card:hover {
  border-color: var(--neon-purple);
  box-shadow: var(--shadow-neon-purple);
  transform: translateY(-4px);
}

.ai-tool-icon {
  font-size: 1.8rem;
  margin-bottom: 10px;
}

.ai-tool-name {
  font-size: 0.9rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 4px;
}

.ai-tool-desc {
  font-size: 0.78rem;
  color: var(--text-muted);
}

/* ---------- 专家模块 ---------- */
.experts-section {
  background: var(--bg-secondary);
}

.experts-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
  gap: 24px;
}

.expert-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 28px 20px;
  text-align: center;
  transition: var(--transition);
}

.expert-card:hover {
  border-color: var(--neon-gold);
  box-shadow: var(--shadow-neon-gold);
  transform: translateY(-6px);
}

.expert-avatar {
  width: 80px;
  height: 80px;
  border-radius: 50%;
  overflow: hidden;
  margin: 0 auto 14px;
  border: 2px solid var(--border-gold);
  box-shadow: var(--shadow-neon-gold);
}

.expert-avatar img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.expert-name {
  font-size: 1rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 4px;
}

.expert-role {
  font-size: 0.8rem;
  color: var(--neon-gold);
  margin-bottom: 10px;
}

.expert-desc {
  font-size: 0.78rem;
  color: var(--text-muted);
  line-height: 1.6;
}

/* ---------- 用户评价 ---------- */
.reviews-section {
  background: var(--bg-primary);
}

.reviews-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 24px;
}

.review-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 24px;
  transition: var(--transition);
  position: relative;
}

.review-card::before {
  content: '"';
  position: absolute;
  top: 12px;
  right: 20px;
  font-size: 4rem;
  color: rgba(155, 89, 182, 0.15);
  font-family: Georgia, serif;
  line-height: 1;
}

.review-card:hover {
  border-color: var(--neon-purple);
  box-shadow: var(--shadow-neon-purple);
}

.review-stars {
  color: var(--neon-gold);
  font-size: 0.9rem;
  margin-bottom: 12px;
  letter-spacing: 2px;
}

.review-text {
  font-size: 0.9rem;
  color: var(--text-secondary);
  line-height: 1.7;
  margin-bottom: 16px;
}

.review-user {
  display: flex;
  align-items: center;
  gap: 10px;
}

.review-avatar {
  width: 36px;
  height: 36px;
  border-radius: 50%;
  background: var(--gradient-gold-purple);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.85rem;
  font-weight: 700;
  color: #0a0a0f;
  flex-shrink: 0;
}

.review-name {
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--text-primary);
}

.review-date {
  font-size: 0.75rem;
  color: var(--text-muted);
}

/* ---------- 合作模块 ---------- */
.partners-section {
  background: var(--bg-secondary);
}

.partners-logos {
  display: flex;
  flex-wrap: wrap;
  gap: 20px;
  justify-content: center;
  margin-bottom: 60px;
}

.partner-logo {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 16px 28px;
  font-size: 0.9rem;
  font-weight: 700;
  color: var(--text-muted);
  transition: var(--transition);
  cursor: default;
}

.partner-logo:hover {
  border-color: var(--neon-gold);
  color: var(--neon-gold);
  box-shadow: var(--shadow-neon-gold);
}

/* ---------- FAQ ---------- */
.faq-list {
  max-width: 800px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.faq-item {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  overflow: hidden;
  transition: var(--transition);
}

.faq-item.open {
  border-color: var(--neon-gold);
  box-shadow: var(--shadow-neon-gold);
}

.faq-q {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 18px 22px;
  cursor: pointer;
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--text-primary);
  transition: var(--transition);
  gap: 12px;
}

.faq-q:hover {
  color: var(--neon-gold);
}

.faq-arrow {
  flex-shrink: 0;
  width: 22px;
  height: 22px;
  background: rgba(240, 180, 41, 0.1);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.7rem;
  color: var(--neon-gold);
  transition: transform 0.3s ease;
}

.faq-item.open .faq-arrow {
  transform: rotate(180deg);
}

.faq-a {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.4s ease, padding 0.3s ease;
  font-size: 0.88rem;
  color: var(--text-secondary);
  line-height: 1.7;
  padding: 0 22px;
}

.faq-item.open .faq-a {
  max-height: 200px;
  padding: 0 22px 18px;
}

/* ---------- 联系模块 ---------- */
.contact-section {
  background: var(--bg-primary);
}

.contact-grid {
  display: grid;
  grid-template-columns: 1fr 1fr 1fr;
  gap: 32px;
}

.contact-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 32px 24px;
  text-align: center;
  transition: var(--transition);
}

.contact-card:hover {
  border-color: var(--neon-purple);
  box-shadow: var(--shadow-neon-purple);
}

.contact-icon {
  font-size: 2.2rem;
  margin-bottom: 14px;
}

.contact-label {
  font-size: 0.8rem;
  color: var(--text-muted);
  margin-bottom: 6px;
  text-transform: uppercase;
  letter-spacing: 0.1em;
}

.contact-value {
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--text-primary);
}

.qr-box {
  width: 100px;
  height: 100px;
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.7rem;
  color: var(--text-muted);
  text-align: center;
}

/* ---------- 页脚 ---------- */
.footer {
  background: var(--bg-secondary);
  border-top: 1px solid var(--border-color);
  padding: 48px 0 24px;
}

.footer-top {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 40px;
  margin-bottom: 40px;
}

.footer-brand .logo {
  font-size: 1.3rem;
  margin-bottom: 14px;
  display: inline-flex;
}

.footer-brand p {
  font-size: 0.85rem;
  color: var(--text-muted);
  line-height: 1.7;
  margin-bottom: 16px;
}

.footer-social {
  display: flex;
  gap: 10px;
}

.social-btn {
  width: 36px;
  height: 36px;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.9rem;
  color: var(--text-muted);
  transition: var(--transition);
  cursor: pointer;
}

.social-btn:hover {
  border-color: var(--neon-gold);
  color: var(--neon-gold);
  box-shadow: var(--shadow-neon-gold);
}

.footer-col h4 {
  font-size: 0.9rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 16px;
}

.footer-col ul li {
  margin-bottom: 8px;
}

.footer-col ul li a {
  font-size: 0.82rem;
  color: var(--text-muted);
  transition: var(--transition);
}

.footer-col ul li a:hover {
  color: var(--neon-gold);
}

.footer-bottom {
  border-top: 1px solid var(--border-color);
  padding-top: 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 12px;
}

.footer-copy {
  font-size: 0.8rem;
  color: var(--text-muted);
}

.footer-copy a {
  color: var(--text-muted);
}

.footer-copy a:hover {
  color: var(--neon-gold);
}

.footer-links {
  display: flex;
  gap: 16px;
}

.footer-links a {
  font-size: 0.8rem;
  color: var(--text-muted);
}

.footer-links a:hover {
  color: var(--neon-gold);
}

/* ---------- 内页通用 ---------- */
.page-hero {
  padding: 140px 0 80px;
  text-align: center;
  background: var(--bg-secondary);
  position: relative;
  overflow: hidden;
}

.page-hero::before {
  content: '';
  position: absolute;
  top: -50%;
  left: 50%;
  transform: translateX(-50%);
  width: 600px;
  height: 600px;
  background: radial-gradient(circle, rgba(155, 89, 182, 0.15) 0%, transparent 70%);
  pointer-events: none;
}

.breadcrumb {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.82rem;
  color: var(--text-muted);
  justify-content: center;
  margin-bottom: 20px;
}

.breadcrumb a {
  color: var(--text-muted);
}

.breadcrumb a:hover {
  color: var(--neon-gold);
}

.breadcrumb span {
  color: var(--text-muted);
}

/* ---------- 滚动动画 ---------- */
.fade-up {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.fade-up.visible {
  opacity: 1;
  transform: translateY(0);
}

/* ---------- 响应式 ---------- */
@media (max-width: 1024px) {
  .footer-top {
    grid-template-columns: 1fr 1fr;
  }
  .ai-grid {
    grid-template-columns: 1fr;
  }
  .contact-grid {
    grid-template-columns: 1fr 1fr;
  }
}

@media (max-width: 768px) {
  .nav-menu {
    display: none;
    position: fixed;
    top: 68px;
    left: 0;
    width: 100%;
    background: rgba(10, 10, 15, 0.98);
    flex-direction: column;
    padding: 20px;
    gap: 4px;
    border-bottom: 1px solid var(--border-color);
  }
  .nav-menu.open {
    display: flex;
  }
  .nav-toggle {
    display: flex;
  }
  .community-grid {
    grid-template-columns: 1fr;
  }
  .contact-grid {
    grid-template-columns: 1fr;
  }
  .footer-top {
    grid-template-columns: 1fr;
    gap: 28px;
  }
  .footer-bottom {
    flex-direction: column;
    text-align: center;
  }
  .hero-stats {
    gap: 24px;
  }
  .section {
    padding: 56px 0;
  }
  .video-grid {
    grid-template-columns: 1fr 1fr;
  }
}

@media (max-width: 480px) {
  .video-grid {
    grid-template-columns: 1fr;
  }
  .hero-btns {
    flex-direction: column;
    align-items: center;
  }
  .btn-primary, .btn-outline {
    width: 100%;
    justify-content: center;
  }
  .experts-grid {
    grid-template-columns: 1fr 1fr;
  }
}

/* ---------- 滚动条 ---------- */
::-webkit-scrollbar {
  width: 6px;
}

::-webkit-scrollbar-track {
  background: var(--bg-primary);
}

::-webkit-scrollbar-thumb {
  background: var(--border-color);
  border-radius: 3px;
}

::-webkit-scrollbar-thumb:hover {
  background: var(--neon-purple);
}

/* ---------- 选中文本 ---------- */
::selection {
  background: rgba(155, 89, 182, 0.35);
  color: var(--text-primary);
}

/* ---------- 加载动画 ---------- */
.page-loader {
  position: fixed;
  inset: 0;
  background: var(--bg-primary);
  z-index: 9999;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: opacity 0.5s ease;
}

.page-loader.hidden {
  opacity: 0;
  pointer-events: none;
}

.loader-logo {
  font-size: 2rem;
  font-weight: 900;
  background: var(--gradient-gold-purple);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  animation: logoBreath 1.5s ease-in-out infinite;
}

@keyframes logoBreath {
  0%, 100% { opacity: 0.6; transform: scale(0.97); }
  50% { opacity: 1; transform: scale(1.03); }
}

/* ---------- 内页内容区 ---------- */
.inner-content {
  padding: 60px 0;
}

.inner-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 24px;
}

.inner-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  overflow: hidden;
  transition: var(--transition);
}

.inner-card:hover {
  border-color: var(--neon-purple);
  box-shadow: var(--shadow-neon-purple);
  transform: translateY(-4px);
}

.inner-card-img {
  aspect-ratio: 16/9;
  overflow: hidden;
}

.inner-card-img img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.5s ease;
}

.inner-card:hover .inner-card-img img {
  transform: scale(1.06);
}

.inner-card-body {
  padding: 18px;
}

.inner-card-tag {
  display: inline-block;
  font-size: 0.72rem;
  font-weight: 700;
  color: var(--neon-gold);
  background: rgba(240, 180, 41, 0.1);
  border: 1px solid var(--border-gold);
  padding: 2px 10px;
  border-radius: 4px;
  margin-bottom: 8px;
}

.inner-card-title {
  font-size: 0.95rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 8px;
  line-height: 1.4;
}

.inner-card-desc {
  font-size: 0.82rem;
  color: var(--text-muted);
  line-height: 1.6;
}

/* ---------- 更新时间 ---------- */
.update-time {
  font-size: 0.78rem;
  color: var(--text-muted);
  margin-top: 6px;
}

/* ---------- 霓虹分割线 ---------- */
.neon-divider {
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--neon-purple), var(--neon-gold), var(--neon-purple), transparent);
  margin: 0;
  opacity: 0.5;
}