/* =============================================
   17C 官网 - 暗黑潮流赛博风格主样式表
   ============================================= */

/* ---------- 基础重置 ---------- */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; font-size: 16px; }
body {
  background: #080810;
  color: #e0e0f0;
  font-family: 'PingFang SC', 'Microsoft YaHei', 'Noto Sans SC', sans-serif;
  line-height: 1.7;
  overflow-x: hidden;
}
a { color: inherit; text-decoration: none; }
img { max-width: 100%; height: auto; display: block; }
ul, ol { list-style: none; }

/* ---------- CSS 变量 ---------- */
:root {
  --gold: #f0c040;
  --purple: #9b59ff;
  --neon-blue: #00d4ff;
  --dark-bg: #080810;
  --card-bg: #0f0f1e;
  --border: rgba(155, 89, 255, 0.25);
  --text-muted: #8888aa;
  --gradient: linear-gradient(135deg, #f0c040 0%, #9b59ff 100%);
  --glow-gold: 0 0 20px rgba(240,192,64,0.4);
  --glow-purple: 0 0 20px rgba(155,89,255,0.4);
  --radius: 12px;
  --transition: 0.3s ease;
}

/* ---------- 滚动条 ---------- */
::-webkit-scrollbar { width: 6px; }
::-webkit-scrollbar-track { background: #080810; }
::-webkit-scrollbar-thumb { background: var(--purple); border-radius: 3px; }

/* ---------- 粒子背景 ---------- */
#particles-canvas {
  position: fixed; top: 0; left: 0;
  width: 100%; height: 100%;
  pointer-events: none; z-index: 0;
  opacity: 0.35;
}

/* ---------- 导航栏 ---------- */
.site-header {
  position: sticky; top: 0; z-index: 1000;
  background: rgba(8,8,16,0.92);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
}
.nav-inner {
  max-width: 1280px; margin: 0 auto;
  display: flex; align-items: center;
  padding: 0 24px; height: 64px;
  gap: 24px;
}
.nav-logo {
  font-size: 1.8rem; font-weight: 900;
  background: var(--gradient);
  -webkit-background-clip: text; -webkit-text-fill-color: transparent;
  letter-spacing: 2px; white-space: nowrap;
  flex-shrink: 0;
}
.nav-links {
  display: flex; align-items: center; gap: 4px;
  flex: 1; justify-content: center;
}
.nav-links a {
  padding: 6px 14px; border-radius: 6px;
  font-size: 0.9rem; font-weight: 500;
  color: #c0c0d8;
  transition: color var(--transition), background var(--transition);
  white-space: nowrap;
}
.nav-links a:hover, .nav-links a.active {
  color: var(--gold);
  background: rgba(240,192,64,0.08);
}
.nav-actions { display: flex; align-items: center; gap: 12px; flex-shrink: 0; }
.btn-join {
  background: var(--gradient); color: #000;
  padding: 8px 20px; border-radius: 20px;
  font-weight: 700; font-size: 0.85rem;
  transition: box-shadow var(--transition), transform var(--transition);
  white-space: nowrap;
}
.btn-join:hover { box-shadow: var(--glow-gold); transform: translateY(-1px); }

/* ---------- 搜索框 ---------- */
.search-bar-wrap {
  background: rgba(15,15,30,0.9);
  border-bottom: 1px solid var(--border);
  padding: 10px 24px;
}
.search-inner {
  max-width: 700px; margin: 0 auto;
  display: flex; align-items: center;
  background: rgba(255,255,255,0.04);
  border: 1px solid var(--border);
  border-radius: 30px;
  overflow: hidden;
  transition: border-color var(--transition), box-shadow var(--transition);
}
.search-inner:focus-within {
  border-color: var(--purple);
  box-shadow: var(--glow-purple);
}
.search-inner input {
  flex: 1; background: transparent; border: none; outline: none;
  color: #e0e0f0; padding: 10px 20px; font-size: 0.95rem;
}
.search-inner input::placeholder { color: var(--text-muted); }
.search-inner button {
  background: var(--gradient); border: none; cursor: pointer;
  padding: 10px 24px; color: #000; font-weight: 700;
  font-size: 0.9rem; transition: opacity var(--transition);
}
.search-inner button:hover { opacity: 0.85; }

/* ---------- 通用容器 ---------- */
.container { max-width: 1280px; margin: 0 auto; padding: 0 24px; }
.section { padding: 80px 0; position: relative; z-index: 1; }
.section-alt { background: rgba(15,15,30,0.6); }

/* ---------- 标题系统 ---------- */
.section-title {
  font-size: clamp(1.6rem, 3vw, 2.2rem);
  font-weight: 900; text-align: center;
  margin-bottom: 12px;
  background: var(--gradient);
  -webkit-background-clip: text; -webkit-text-fill-color: transparent;
}
.section-sub {
  text-align: center; color: var(--text-muted);
  font-size: 0.95rem; margin-bottom: 48px;
}
.tag-badge {
  display: inline-block;
  background: rgba(155,89,255,0.15);
  border: 1px solid rgba(155,89,255,0.4);
  color: var(--purple); font-size: 0.75rem;
  padding: 3px 10px; border-radius: 20px;
  margin-bottom: 12px; text-transform: uppercase;
  letter-spacing: 1px;
}

/* ---------- Hero Banner ---------- */
.hero {
  position: relative; min-height: 88vh;
  display: flex; align-items: center; justify-content: center;
  overflow: hidden;
}
.hero-bg {
  position: absolute; inset: 0;
  background-image: url('../images/banner.jpg');
  background-size: cover; background-position: center;
  filter: brightness(0.4) saturate(1.2);
}
.hero-overlay {
  position: absolute; inset: 0;
  background: linear-gradient(180deg, rgba(8,8,16,0.2) 0%, rgba(8,8,16,0.8) 100%);
}
.hero-content {
  position: relative; z-index: 2;
  text-align: center; padding: 40px 24px;
  max-width: 860px;
}
.hero-eyebrow {
  font-size: 0.85rem; letter-spacing: 4px;
  color: var(--gold); text-transform: uppercase;
  margin-bottom: 20px;
}
.hero-title {
  font-size: clamp(2.4rem, 6vw, 4.5rem);
  font-weight: 900; line-height: 1.1;
  margin-bottom: 20px;
}
.hero-title .brand { background: var(--gradient); -webkit-background-clip: text; -webkit-text-fill-color: transparent; }
.hero-desc {
  font-size: clamp(1rem, 2vw, 1.2rem);
  color: #b0b0cc; margin-bottom: 36px; line-height: 1.8;
}
.hero-btns { display: flex; gap: 16px; justify-content: center; flex-wrap: wrap; }
.btn-primary {
  background: var(--gradient); color: #000;
  padding: 14px 36px; border-radius: 30px;
  font-weight: 800; font-size: 1rem;
  transition: box-shadow var(--transition), transform var(--transition);
}
.btn-primary:hover { box-shadow: var(--glow-gold); transform: translateY(-2px); }
.btn-outline {
  border: 1px solid var(--purple); color: var(--purple);
  padding: 14px 36px; border-radius: 30px;
  font-weight: 700; font-size: 1rem;
  transition: background var(--transition), box-shadow var(--transition);
}
.btn-outline:hover { background: rgba(155,89,255,0.12); box-shadow: var(--glow-purple); }
.hero-stats {
  display: flex; gap: 40px; justify-content: center;
  margin-top: 48px; flex-wrap: wrap;
}
.hero-stat { text-align: center; }
.hero-stat .num {
  font-size: 2rem; font-weight: 900;
  background: var(--gradient); -webkit-background-clip: text; -webkit-text-fill-color: transparent;
}
.hero-stat .label { font-size: 0.8rem; color: var(--text-muted); }

/* ---------- 视频卡片网格 ---------- */
.video-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 24px;
}
.video-card {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  transition: transform var(--transition), box-shadow var(--transition), border-color var(--transition);
  cursor: pointer;
}
.video-card:hover {
  transform: translateY(-6px);
  box-shadow: 0 16px 40px rgba(155,89,255,0.25);
  border-color: var(--purple);
}
.video-thumb {
  position: relative; overflow: hidden;
  aspect-ratio: 16/9;
}
.video-thumb img {
  width: 100%; height: 100%; object-fit: cover;
  transition: transform 0.5s ease;
}
.video-card:hover .video-thumb img { transform: scale(1.06); }
.video-play-btn {
  position: absolute; inset: 0;
  display: flex; align-items: center; justify-content: center;
  background: rgba(0,0,0,0.4);
  opacity: 0; transition: opacity var(--transition);
}
.video-card:hover .video-play-btn { opacity: 1; }
.play-icon {
  width: 56px; height: 56px;
  background: var(--gradient);
  border-radius: 50%;
  display: flex; align-items: center; justify-content: center;
  box-shadow: var(--glow-gold);
}
.play-icon::after {
  content: '';
  border-left: 18px solid #000;
  border-top: 11px solid transparent;
  border-bottom: 11px solid transparent;
  margin-left: 4px;
}
.video-duration {
  position: absolute; bottom: 8px; right: 8px;
  background: rgba(0,0,0,0.75); color: #fff;
  font-size: 0.75rem; padding: 2px 6px; border-radius: 4px;
}
.video-info { padding: 16px; }
.video-title {
  font-size: 0.95rem; font-weight: 700;
  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: 16px;
  font-size: 0.78rem; color: var(--text-muted);
}
.video-meta span { display: flex; align-items: center; gap: 4px; }
.video-tag {
  display: inline-block;
  background: rgba(240,192,64,0.1); color: var(--gold);
  font-size: 0.7rem; padding: 2px 8px; border-radius: 10px;
  margin-bottom: 8px;
}

/* ---------- 社区模块 ---------- */
.community-grid {
  display: grid; grid-template-columns: 1fr 1fr; gap: 32px;
}
.community-card {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius); padding: 28px;
}
.community-card h3 {
  font-size: 1.1rem; font-weight: 800;
  margin-bottom: 16px; color: var(--gold);
}
.topic-list { display: flex; flex-wrap: wrap; gap: 10px; }
.topic-tag {
  background: rgba(155,89,255,0.12);
  border: 1px solid rgba(155,89,255,0.3);
  color: var(--purple); padding: 6px 14px;
  border-radius: 20px; font-size: 0.85rem;
  transition: background var(--transition);
  cursor: pointer;
}
.topic-tag:hover { background: rgba(155,89,255,0.25); }
.danmu-list { display: flex; flex-direction: column; gap: 10px; }
.danmu-item {
  background: rgba(255,255,255,0.03);
  border-left: 3px solid var(--purple);
  padding: 10px 14px; border-radius: 0 8px 8px 0;
  font-size: 0.85rem; color: #c0c0d8;
  animation: slideIn 0.5s ease;
}
@keyframes slideIn { from { opacity:0; transform:translateX(-10px); } to { opacity:1; transform:none; } }

/* ---------- AI 模块 ---------- */
.ai-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
  gap: 24px;
}
.ai-card {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius); padding: 28px;
  text-align: center;
  transition: transform var(--transition), box-shadow var(--transition);
}
.ai-card:hover { transform: translateY(-4px); box-shadow: var(--glow-purple); }
.ai-icon {
  font-size: 2.5rem; margin-bottom: 16px;
  display: block;
}
.ai-card h3 { font-size: 1rem; font-weight: 800; margin-bottom: 8px; color: var(--gold); }
.ai-card p { font-size: 0.85rem; color: var(--text-muted); line-height: 1.6; }

/* ---------- 专家模块 ---------- */
.experts-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
  gap: 28px;
}
.expert-card {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius); padding: 28px 20px;
  text-align: center;
  transition: transform var(--transition), border-color var(--transition);
}
.expert-card:hover { transform: translateY(-4px); border-color: var(--gold); }
.expert-avatar {
  width: 90px; height: 90px; border-radius: 50%;
  margin: 0 auto 16px;
  border: 2px solid var(--purple);
  overflow: hidden;
}
.expert-avatar img { width: 100%; height: 100%; object-fit: cover; }
.expert-name { font-size: 1rem; font-weight: 800; margin-bottom: 4px; }
.expert-role { font-size: 0.8rem; color: var(--gold); margin-bottom: 10px; }
.expert-desc { font-size: 0.8rem; color: var(--text-muted); line-height: 1.5; }

/* ---------- 评价模块 ---------- */
.reviews-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 24px;
}
.review-card {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius); padding: 24px;
  transition: border-color var(--transition);
}
.review-card:hover { border-color: var(--gold); }
.review-stars { color: var(--gold); font-size: 1rem; margin-bottom: 12px; }
.review-text { font-size: 0.9rem; color: #c0c0d8; 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); display: flex; align-items: center;
  justify-content: center; font-weight: 800; font-size: 0.9rem; color: #000;
  flex-shrink: 0;
}
.review-name { font-size: 0.85rem; font-weight: 700; }
.review-date { font-size: 0.75rem; color: var(--text-muted); }

/* ---------- FAQ 模块 ---------- */
.faq-list { max-width: 860px; margin: 0 auto; }
.faq-item {
  border: 1px solid var(--border);
  border-radius: var(--radius); margin-bottom: 12px;
  overflow: hidden;
  transition: border-color var(--transition);
}
.faq-item:hover { border-color: var(--purple); }
.faq-q {
  padding: 18px 24px;
  display: flex; justify-content: space-between; align-items: center;
  cursor: pointer; font-weight: 700; font-size: 0.95rem;
  background: var(--card-bg);
  transition: background var(--transition);
}
.faq-q:hover { background: rgba(155,89,255,0.06); }
.faq-q .arrow {
  width: 20px; height: 20px; flex-shrink: 0;
  border-right: 2px solid var(--purple);
  border-bottom: 2px solid var(--purple);
  transform: rotate(45deg); transition: transform var(--transition);
  margin-top: -4px;
}
.faq-item.open .faq-q .arrow { transform: rotate(-135deg); margin-top: 4px; }
.faq-a {
  max-height: 0; overflow: hidden;
  transition: max-height 0.4s ease, padding 0.3s ease;
  background: rgba(15,15,30,0.5);
}
.faq-item.open .faq-a { max-height: 200px; }
.faq-a p { padding: 16px 24px; font-size: 0.9rem; color: var(--text-muted); line-height: 1.7; }

/* ---------- 合作伙伴 ---------- */
.partners-grid {
  display: flex; flex-wrap: wrap;
  gap: 20px; justify-content: center; align-items: center;
}
.partner-logo {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: 10px; padding: 16px 28px;
  font-size: 0.9rem; font-weight: 700;
  color: var(--text-muted);
  transition: color var(--transition), border-color var(--transition);
}
.partner-logo:hover { color: var(--gold); border-color: var(--gold); }

/* ---------- 联系模块 ---------- */
.contact-grid {
  display: grid; grid-template-columns: 1fr 1fr 1fr; gap: 32px;
}
.contact-card {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius); padding: 32px;
  text-align: center;
}
.contact-card h3 { font-size: 1rem; font-weight: 800; margin-bottom: 16px; color: var(--gold); }
.contact-card p { font-size: 0.85rem; color: var(--text-muted); line-height: 1.8; }
.qr-placeholder {
  width: 100px; height: 100px; margin: 16px auto;
  background: linear-gradient(135deg, rgba(155,89,255,0.2), rgba(240,192,64,0.2));
  border: 1px dashed var(--border);
  border-radius: 8px; display: flex; align-items: center;
  justify-content: center; font-size: 0.75rem; color: var(--text-muted);
}

/* ---------- 页脚 ---------- */
.site-footer {
  background: rgba(5,5,12,0.98);
  border-top: 1px solid var(--border);
  padding: 48px 0 24px;
  position: relative; z-index: 1;
}
.footer-top {
  max-width: 1280px; margin: 0 auto; padding: 0 24px;
  display: grid; grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 40px; margin-bottom: 40px;
}
.footer-brand .logo {
  font-size: 2rem; font-weight: 900;
  background: var(--gradient);
  -webkit-background-clip: text; -webkit-text-fill-color: transparent;
  margin-bottom: 12px;
}
.footer-brand p { font-size: 0.85rem; color: var(--text-muted); line-height: 1.8; }
.footer-col h4 { font-size: 0.9rem; font-weight: 800; color: var(--gold); margin-bottom: 16px; }
.footer-col ul li { margin-bottom: 8px; }
.footer-col ul li a { font-size: 0.85rem; color: var(--text-muted); transition: color var(--transition); }
.footer-col ul li a:hover { color: var(--gold); }
.footer-bottom {
  max-width: 1280px; margin: 0 auto; padding: 20px 24px 0;
  border-top: 1px solid var(--border);
  display: flex; justify-content: space-between; align-items: center;
  flex-wrap: wrap; gap: 12px;
}
.footer-bottom p { font-size: 0.8rem; color: var(--text-muted); }
.footer-social { display: flex; gap: 12px; }
.footer-social a {
  width: 32px; height: 32px; border-radius: 50%;
  background: rgba(155,89,255,0.12);
  border: 1px solid var(--border);
  display: flex; align-items: center; justify-content: center;
  font-size: 0.8rem; color: var(--text-muted);
  transition: background var(--transition), color var(--transition);
}
.footer-social a:hover { background: var(--purple); color: #fff; }

/* ---------- 内页 Banner ---------- */
.inner-hero {
  background: linear-gradient(135deg, rgba(155,89,255,0.15) 0%, rgba(240,192,64,0.08) 100%);
  border-bottom: 1px solid var(--border);
  padding: 60px 24px;
  text-align: center; position: relative; z-index: 1;
}
.inner-hero h1 {
  font-size: clamp(1.8rem, 4vw, 3rem);
  font-weight: 900; margin-bottom: 12px;
  background: var(--gradient);
  -webkit-background-clip: text; -webkit-text-fill-color: transparent;
}
.inner-hero p { color: var(--text-muted); font-size: 1rem; }
.breadcrumb {
  font-size: 0.8rem; color: var(--text-muted);
  margin-bottom: 16px;
}
.breadcrumb a { color: var(--purple); }
.breadcrumb span { color: var(--text-muted); margin: 0 6px; }

/* ---------- 响应式 ---------- */
@media (max-width: 1024px) {
  .footer-top { grid-template-columns: 1fr 1fr; }
  .contact-grid { grid-template-columns: 1fr 1fr; }
  .community-grid { grid-template-columns: 1fr; }
}
@media (max-width: 768px) {
  .nav-links { display: none; }
  .nav-inner { justify-content: space-between; }
  .hero { min-height: 70vh; }
  .hero-stats { gap: 24px; }
  .footer-top { grid-template-columns: 1fr; gap: 24px; }
  .footer-bottom { flex-direction: column; text-align: center; }
  .contact-grid { grid-template-columns: 1fr; }
  .mobile-menu-btn {
    display: flex; flex-direction: column; gap: 5px;
    cursor: pointer; padding: 4px;
  }
  .mobile-menu-btn span {
    width: 24px; height: 2px; background: var(--gold);
    border-radius: 2px; transition: var(--transition);
  }
}
@media (min-width: 769px) {
  .mobile-menu-btn { display: none; }
}
@media (max-width: 480px) {
  .section { padding: 48px 0; }
  .video-grid { grid-template-columns: 1fr; }
  .experts-grid { grid-template-columns: 1fr 1fr; }
  .reviews-grid { grid-template-columns: 1fr; }
}

/* ---------- 动画 ---------- */
@keyframes fadeUp {
  from { opacity: 0; transform: translateY(30px); }
  to { opacity: 1; transform: translateY(0); }
}
.fade-up { animation: fadeUp 0.7s ease both; }
.delay-1 { animation-delay: 0.1s; }
.delay-2 { animation-delay: 0.2s; }
.delay-3 { animation-delay: 0.3s; }

/* ---------- 弹幕跑马灯 ---------- */
.marquee-wrap { overflow: hidden; white-space: nowrap; }
.marquee-track {
  display: inline-flex; gap: 40px;
  animation: marquee 30s linear infinite;
}
.marquee-track:hover { animation-play-state: paused; }
@keyframes marquee { from { transform: translateX(0); } to { transform: translateX(-50%); } }
.marquee-item {
  background: rgba(155,89,255,0.08);
  border: 1px solid rgba(155,89,255,0.2);
  padding: 8px 20px; border-radius: 20px;
  font-size: 0.85rem; color: #c0c0d8;
  white-space: nowrap;
}

/* ---------- 更新时间标签 ---------- */
.update-badge {
  display: inline-flex; align-items: center; gap: 6px;
  background: rgba(240,192,64,0.1);
  border: 1px solid rgba(240,192,64,0.3);
  color: var(--gold); font-size: 0.75rem;
  padding: 4px 12px; border-radius: 20px;
}
.update-badge::before { content: '●'; font-size: 0.5rem; animation: blink 1.5s infinite; }
@keyframes blink { 0%,100%{opacity:1;} 50%{opacity:0.2;} }

/* ---------- 加载占位 ---------- */
.skeleton {
  background: linear-gradient(90deg, rgba(255,255,255,0.03) 25%, rgba(255,255,255,0.07) 50%, rgba(255,255,255,0.03) 75%);
  background-size: 200% 100%;
  animation: shimmer 1.5s infinite;
  border-radius: 6px;
}
@keyframes shimmer { from{background-position:200% 0;} to{background-position:-200% 0;} }