/* ============================================
   91 经典社区在线平台 - 全站样式
   品牌: 草榴 | 域名: piLLrvi.cn
   原创配色方案 & 原创布局
   ============================================ */

/* CSS Variables */
:root {
  --primary: #E63946;
  --primary-dark: #C62833;
  --secondary: #1D3557;
  --accent: #F4A261;
  --bg-dark: #0D1117;
  --bg-card: #161B22;
  --bg-card-hover: #1C2333;
  --text-main: #F1FAEE;
  --text-secondary: #A8DADC;
  --text-muted: #8B949E;
  --border-color: #30363D;
  --gradient-primary: linear-gradient(135deg, #E63946 0%, #F4A261 100%);
  --gradient-dark: linear-gradient(180deg, #0D1117 0%, #161B22 100%);
  --shadow-card: 0 4px 24px rgba(0,0,0,0.4);
  --shadow-hover: 0 8px 40px rgba(230,57,70,0.2);
  --radius: 12px;
  --radius-sm: 8px;
  --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

/* Reset & Base */
*, *::before, *::after { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; font-size: 16px; }
body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Arial, 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(--primary); }
img { max-width: 100%; height: auto; display: block; }
ul, ol { list-style: none; }

/* Container */
.container { max-width: 1280px; margin: 0 auto; padding: 0 20px; }
.container-wide { max-width: 1440px; margin: 0 auto; padding: 0 20px; }

/* ============ HEADER ============ */
.site-header {
  position: fixed; top: 0; left: 0; width: 100%; z-index: 1000;
  background: rgba(13,17,23,0.92);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--border-color);
  transition: var(--transition);
}
.header-inner {
  display: flex; align-items: center; justify-content: space-between;
  max-width: 1440px; margin: 0 auto; padding: 0 24px; height: 68px;
}
.logo-wrap { display: flex; align-items: center; gap: 10px; }
.logo-wrap img { width: 42px; height: 42px; border-radius: 8px; }
.logo-text { font-size: 1.5rem; font-weight: 800; color: var(--primary); letter-spacing: 1px; }
.logo-text span { color: var(--text-main); font-weight: 400; font-size: 0.8rem; margin-left: 6px; }

/* Navigation */
.main-nav { display: flex; align-items: center; gap: 0; }
.main-nav a {
  padding: 8px 18px; font-size: 0.92rem; color: var(--text-secondary);
  border-radius: var(--radius-sm); transition: var(--transition); font-weight: 500;
}
.main-nav a:hover, .main-nav a.active {
  color: var(--text-main); background: rgba(230,57,70,0.12);
}
.mobile-toggle { display: none; cursor: pointer; font-size: 1.5rem; color: var(--text-main); background: none; border: none; }

/* Search Bar */
.search-bar {
  background: var(--bg-card); border-bottom: 1px solid var(--border-color);
  padding: 12px 0; margin-top: 68px;
}
.search-inner {
  max-width: 680px; margin: 0 auto; display: flex; gap: 10px; padding: 0 20px;
}
.search-inner input {
  flex: 1; padding: 10px 18px; border-radius: 50px; border: 1px solid var(--border-color);
  background: var(--bg-dark); color: var(--text-main); font-size: 0.95rem;
  outline: none; transition: var(--transition);
}
.search-inner input:focus { border-color: var(--primary); box-shadow: 0 0 0 3px rgba(230,57,70,0.15); }
.search-inner input::placeholder { color: var(--text-muted); }
.search-inner button {
  padding: 10px 28px; border-radius: 50px; border: none;
  background: var(--gradient-primary); color: #fff; font-weight: 600;
  cursor: pointer; transition: var(--transition); font-size: 0.95rem;
}
.search-inner button:hover { transform: translateY(-1px); box-shadow: 0 4px 16px rgba(230,57,70,0.3); }

/* ============ BANNER / HERO ============ */
.hero-banner {
  position: relative; width: 100%; min-height: 520px;
  display: flex; align-items: center; justify-content: center;
  overflow: hidden;
}
.hero-banner .hero-bg {
  position: absolute; inset: 0; width: 100%; height: 100%;
  object-fit: cover; filter: brightness(0.35);
}
.hero-overlay {
  position: absolute; inset: 0;
  background: linear-gradient(180deg, rgba(13,17,23,0.3) 0%, rgba(13,17,23,0.85) 100%);
}
.hero-content {
  position: relative; z-index: 2; text-align: center;
  max-width: 800px; padding: 60px 20px;
}
.hero-content h1 {
  font-size: 2.8rem; font-weight: 900; margin-bottom: 16px;
  background: var(--gradient-primary); -webkit-background-clip: text;
  -webkit-text-fill-color: transparent; background-clip: text;
  line-height: 1.2;
}
.hero-content h2 {
  font-size: 1.2rem; font-weight: 400; color: var(--text-secondary);
  margin-bottom: 28px; line-height: 1.6;
}
.hero-tags { display: flex; flex-wrap: wrap; justify-content: center; gap: 10px; margin-bottom: 28px; }
.hero-tags span {
  padding: 6px 16px; border-radius: 50px; font-size: 0.82rem;
  background: rgba(230,57,70,0.15); color: var(--primary); border: 1px solid rgba(230,57,70,0.3);
}
.hero-btn {
  display: inline-block; padding: 14px 40px; border-radius: 50px;
  background: var(--gradient-primary); color: #fff; font-weight: 700;
  font-size: 1.05rem; transition: var(--transition);
  box-shadow: 0 4px 20px rgba(230,57,70,0.3);
}
.hero-btn:hover { transform: translateY(-3px); box-shadow: 0 8px 32px rgba(230,57,70,0.4); color: #fff; }

/* ============ SECTION ============ */
.section { padding: 70px 0; }
.section-alt { background: var(--bg-card); }
.section-title {
  text-align: center; margin-bottom: 48px;
}
.section-title h2 {
  font-size: 2rem; font-weight: 800; margin-bottom: 12px;
  color: var(--text-main);
}
.section-title h2 em {
  font-style: normal; color: var(--primary);
}
.section-title p {
  color: var(--text-muted); font-size: 1rem; max-width: 600px; margin: 0 auto;
}
.section-title .tag-line {
  display: inline-block; padding: 4px 14px; border-radius: 50px;
  background: rgba(230,57,70,0.1); color: var(--primary); font-size: 0.82rem;
  margin-bottom: 10px; font-weight: 600;
}

/* ============ VIDEO CARD GRID ============ */
.video-grid {
  display: grid; grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 24px;
}
.video-card {
  background: var(--bg-card); border-radius: var(--radius);
  overflow: hidden; border: 1px solid var(--border-color);
  transition: var(--transition); cursor: pointer;
}
.video-card:hover {
  transform: translateY(-6px); border-color: var(--primary);
  box-shadow: var(--shadow-hover);
}
.video-thumb {
  position: relative; width: 100%; padding-top: 56.25%; overflow: hidden;
}
.video-thumb img {
  position: absolute; inset: 0; width: 100%; height: 100%; object-fit: cover;
  transition: var(--transition);
}
.video-card:hover .video-thumb img { transform: scale(1.05); }
.video-play-btn {
  position: absolute; top: 50%; left: 50%; transform: translate(-50%, -50%);
  width: 60px; height: 60px; border-radius: 50%;
  background: rgba(230,57,70,0.9); display: flex; align-items: center; justify-content: center;
  opacity: 0; transition: var(--transition);
}
.video-card:hover .video-play-btn { opacity: 1; }
.video-play-btn::after {
  content: ''; width: 0; height: 0;
  border-top: 12px solid transparent; border-bottom: 12px solid transparent;
  border-left: 20px solid #fff; margin-left: 4px;
}
.video-duration {
  position: absolute; bottom: 8px; right: 8px;
  background: rgba(0,0,0,0.8); color: #fff; padding: 2px 8px;
  border-radius: 4px; font-size: 0.78rem;
}
.video-info { padding: 16px; }
.video-info h3 {
  font-size: 1rem; font-weight: 700; margin-bottom: 8px;
  color: var(--text-main); line-height: 1.4;
  display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical; overflow: hidden;
}
.video-meta {
  display: flex; align-items: center; gap: 14px;
  color: var(--text-muted); font-size: 0.82rem;
}
.video-meta span { display: flex; align-items: center; gap: 4px; }
.video-tags { display: flex; flex-wrap: wrap; gap: 6px; margin-top: 10px; }
.video-tags span {
  padding: 2px 10px; border-radius: 50px; font-size: 0.72rem;
  background: rgba(168,218,220,0.1); color: var(--text-secondary);
}

/* ============ EXPERT CARDS ============ */
.expert-grid {
  display: grid; grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 24px;
}
.expert-card {
  background: var(--bg-card); border-radius: var(--radius);
  padding: 32px 24px; text-align: center;
  border: 1px solid var(--border-color); transition: var(--transition);
}
.expert-card:hover { transform: translateY(-4px); border-color: var(--accent); box-shadow: var(--shadow-hover); }
.expert-avatar {
  width: 100px; height: 100px; border-radius: 50%; margin: 0 auto 16px;
  overflow: hidden; border: 3px solid var(--primary);
}
.expert-avatar img { width: 100%; height: 100%; object-fit: cover; }
.expert-card h3 { font-size: 1.15rem; font-weight: 700; margin-bottom: 4px; }
.expert-card .role { color: var(--primary); font-size: 0.88rem; margin-bottom: 12px; }
.expert-card p { color: var(--text-muted); font-size: 0.88rem; margin-bottom: 16px; line-height: 1.6; }
.expert-links { display: flex; justify-content: center; gap: 10px; }
.expert-links a {
  padding: 6px 16px; border-radius: 50px; font-size: 0.82rem;
  border: 1px solid var(--border-color); color: var(--text-secondary);
}
.expert-links a:hover { border-color: var(--primary); color: var(--primary); }

/* ============ FAQ ============ */
.faq-list { max-width: 800px; margin: 0 auto; }
.faq-item {
  background: var(--bg-card); border-radius: var(--radius-sm);
  margin-bottom: 12px; border: 1px solid var(--border-color);
  overflow: hidden;
}
.faq-question {
  padding: 18px 24px; cursor: pointer; display: flex;
  justify-content: space-between; align-items: center;
  font-weight: 600; font-size: 0.98rem; transition: var(--transition);
}
.faq-question:hover { color: var(--primary); }
.faq-question .arrow { transition: var(--transition); font-size: 1.2rem; color: var(--text-muted); }
.faq-item.active .faq-question .arrow { transform: rotate(180deg); color: var(--primary); }
.faq-answer {
  max-height: 0; overflow: hidden; transition: max-height 0.4s ease;
  padding: 0 24px; color: var(--text-muted); font-size: 0.92rem; line-height: 1.7;
}
.faq-item.active .faq-answer { max-height: 300px; padding: 0 24px 18px; }

/* ============ REVIEWS ============ */
.review-grid {
  display: grid; grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 20px;
}
.review-card {
  background: var(--bg-card); border-radius: var(--radius);
  padding: 24px; border: 1px solid var(--border-color);
}
.review-stars { color: var(--accent); font-size: 0.9rem; margin-bottom: 12px; letter-spacing: 2px; }
.review-card p { color: var(--text-secondary); font-size: 0.92rem; line-height: 1.6; margin-bottom: 14px; font-style: italic; }
.review-author { display: flex; align-items: center; gap: 10px; }
.review-author .avatar {
  width: 36px; height: 36px; border-radius: 50%;
  background: var(--gradient-primary); display: flex; align-items: center; justify-content: center;
  color: #fff; font-weight: 700; font-size: 0.85rem;
}
.review-author .name { font-weight: 600; font-size: 0.88rem; }
.review-author .date { color: var(--text-muted); font-size: 0.78rem; }

/* ============ BRAND WALL ============ */
.brand-wall {
  display: flex; flex-wrap: wrap; justify-content: center; gap: 30px;
  align-items: center;
}
.brand-wall .brand-item {
  padding: 16px 28px; background: var(--bg-card); border-radius: var(--radius-sm);
  border: 1px solid var(--border-color); font-size: 1.1rem; font-weight: 700;
  color: var(--text-muted); transition: var(--transition); letter-spacing: 2px;
}
.brand-wall .brand-item:hover { border-color: var(--primary); color: var(--primary); transform: scale(1.05); }

/* ============ AI MODULE ============ */
.ai-features {
  display: grid; grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 24px;
}
.ai-card {
  background: var(--bg-card); border-radius: var(--radius);
  padding: 32px 24px; border: 1px solid var(--border-color);
  transition: var(--transition); position: relative; overflow: hidden;
}
.ai-card::before {
  content: ''; position: absolute; top: 0; left: 0; width: 100%; height: 3px;
  background: var(--gradient-primary);
}
.ai-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-hover); }
.ai-icon {
  width: 52px; height: 52px; border-radius: 12px; margin-bottom: 18px;
  background: rgba(230,57,70,0.1); display: flex; align-items: center; justify-content: center;
  font-size: 1.5rem;
}
.ai-card h3 { font-size: 1.1rem; font-weight: 700; margin-bottom: 10px; }
.ai-card p { color: var(--text-muted); font-size: 0.9rem; line-height: 1.6; }

/* ============ COMMUNITY ============ */
.community-grid {
  display: grid; grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  gap: 16px;
}
.community-item {
  background: var(--bg-card); border-radius: var(--radius-sm);
  padding: 20px; text-align: center; border: 1px solid var(--border-color);
  transition: var(--transition);
}
.community-item:hover { border-color: var(--accent); transform: translateY(-3px); }
.community-item .count { font-size: 1.8rem; font-weight: 800; color: var(--primary); }
.community-item .label { color: var(--text-muted); font-size: 0.85rem; margin-top: 4px; }

/* ============ CONTACT ============ */
.contact-grid {
  display: grid; grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 24px;
}
.contact-card {
  background: var(--bg-card); border-radius: var(--radius);
  padding: 28px; border: 1px solid var(--border-color);
}
.contact-card h3 { font-size: 1.05rem; font-weight: 700; margin-bottom: 14px; color: var(--accent); }
.contact-card p { color: var(--text-secondary); font-size: 0.9rem; margin-bottom: 8px; }

/* ============ SHARE BUTTONS ============ */
.share-bar {
  display: flex; justify-content: center; gap: 12px; padding: 20px 0;
}
.share-btn {
  padding: 8px 20px; border-radius: 50px; font-size: 0.85rem;
  border: 1px solid var(--border-color); color: var(--text-secondary);
  background: var(--bg-card); cursor: pointer; transition: var(--transition);
}
.share-btn:hover { border-color: var(--primary); color: var(--primary); background: rgba(230,57,70,0.08); }

/* ============ FOOTER ============ */
.site-footer {
  background: #0A0D12; border-top: 1px solid var(--border-color);
  padding: 50px 0 0;
}
.footer-grid {
  display: grid; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 36px; margin-bottom: 40px;
}
.footer-col h4 { font-size: 1rem; font-weight: 700; margin-bottom: 16px; color: var(--text-main); }
.footer-col p, .footer-col a { color: var(--text-muted); font-size: 0.88rem; display: block; margin-bottom: 8px; }
.footer-col a:hover { color: var(--primary); }
.footer-qr { display: flex; gap: 16px; }
.footer-qr img { width: 100px; height: 100px; border-radius: 8px; border: 1px solid var(--border-color); }
.footer-bottom {
  border-top: 1px solid var(--border-color); padding: 20px 0;
  text-align: center; color: var(--text-muted); font-size: 0.82rem;
}

/* ============ BREADCRUMB ============ */
.breadcrumb {
  padding: 14px 0; font-size: 0.85rem; color: var(--text-muted);
  margin-top: 68px;
}
.breadcrumb a { color: var(--text-secondary); }
.breadcrumb a:hover { color: var(--primary); }
.breadcrumb span { margin: 0 8px; }

/* ============ INNER PAGE HERO ============ */
.inner-hero {
  padding: 100px 0 50px; text-align: center;
  background: linear-gradient(180deg, rgba(230,57,70,0.08) 0%, transparent 100%);
  margin-top: 68px;
}
.inner-hero h1 { font-size: 2.2rem; font-weight: 800; margin-bottom: 12px; }
.inner-hero h1 em { font-style: normal; color: var(--primary); }
.inner-hero p { color: var(--text-muted); max-width: 600px; margin: 0 auto; }

/* ============ HOW-TO GUIDE ============ */
.howto-steps {
  max-width: 700px; margin: 0 auto;
}
.howto-step {
  display: flex; gap: 20px; margin-bottom: 28px; align-items: flex-start;
}
.howto-num {
  width: 44px; height: 44px; min-width: 44px; border-radius: 50%;
  background: var(--gradient-primary); display: flex; align-items: center; justify-content: center;
  color: #fff; font-weight: 800; font-size: 1.1rem;
}
.howto-step h3 { font-size: 1.05rem; font-weight: 700; margin-bottom: 4px; }
.howto-step p { color: var(--text-muted); font-size: 0.9rem; }

/* ============ PAGINATION ============ */
.pagination { display: flex; justify-content: center; gap: 8px; margin-top: 40px; }
.pagination a, .pagination span {
  padding: 8px 16px; border-radius: var(--radius-sm);
  border: 1px solid var(--border-color); color: var(--text-secondary);
  font-size: 0.88rem; transition: var(--transition);
}
.pagination a:hover, .pagination .current {
  background: var(--primary); border-color: var(--primary); color: #fff;
}

/* ============ MCP PLACEHOLDER ============ */
.mcp-widget {
  background: var(--bg-card); border: 1px dashed var(--border-color);
  border-radius: var(--radius); padding: 24px; text-align: center;
  color: var(--text-muted); font-size: 0.88rem; margin-top: 20px;
}

/* ============ RESPONSIVE ============ */
@media (max-width: 768px) {
  .hero-content h1 { font-size: 1.8rem; }
  .hero-content h2 { font-size: 1rem; }
  .hero-banner { min-height: 400px; }
  .section { padding: 40px 0; }
  .section-title h2 { font-size: 1.5rem; }
  .video-grid { grid-template-columns: 1fr; }
  .expert-grid { grid-template-columns: 1fr; }
  .main-nav { display: none; position: fixed; top: 68px; left: 0; width: 100%;
    background: var(--bg-dark); flex-direction: column; padding: 20px;
    border-bottom: 1px solid var(--border-color); }
  .main-nav.show { display: flex; }
  .mobile-toggle { display: block; }
  .header-inner { padding: 0 16px; }
  .footer-grid { grid-template-columns: 1fr 1fr; }
  .share-bar { flex-wrap: wrap; }
  .brand-wall .brand-item { padding: 10px 16px; font-size: 0.9rem; }
  .ai-features { grid-template-columns: 1fr; }
  .contact-grid { grid-template-columns: 1fr; }
  .review-grid { grid-template-columns: 1fr; }
  .community-grid { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 480px) {
  .hero-content h1 { font-size: 1.5rem; }
  .footer-grid { grid-template-columns: 1fr; }
  .community-grid { grid-template-columns: 1fr; }
  .search-inner { flex-direction: column; }
  .search-inner button { width: 100%; }
}

/* ============ LAZY LOAD ============ */
img[loading="lazy"] { opacity: 0; transition: opacity 0.5s ease; }
img[loading="lazy"].loaded, img[loading="lazy"][src] { opacity: 1; }

/* ============ ANIMATIONS ============ */
@keyframes fadeInUp {
  from { opacity: 0; transform: translateY(30px); }
  to { opacity: 1; transform: translateY(0); }
}
.fade-in { animation: fadeInUp 0.6s ease forwards; }

/* ============ SCROLLBAR ============ */
::-webkit-scrollbar { width: 8px; }
::-webkit-scrollbar-track { background: var(--bg-dark); }
::-webkit-scrollbar-thumb { background: var(--border-color); border-radius: 4px; }
::-webkit-scrollbar-thumb:hover { background: var(--primary); }