/* ============================================================
   1024社区 - 汽车改装与视频社区 | wzyfyLLr.cn
   原创配色方案：深夜蓝 + 燃橙 + 铬银
   ============================================================ */

/* ---- CSS变量 ---- */
:root {
  --primary: #0A1628;
  --secondary: #FF6B35;
  --accent: #C8D8E8;
  --chrome: #A8B8C8;
  --dark: #060E1A;
  --card-bg: #0F1E35;
  --card-border: #1A2E4A;
  --text-main: #E8EDF5;
  --text-muted: #7A90A8;
  --text-light: #B8C8D8;
  --gradient-hero: linear-gradient(135deg, #060E1A 0%, #0A1628 50%, #0D1F3C 100%);
  --gradient-card: linear-gradient(145deg, #0F1E35, #0A1628);
  --gradient-orange: linear-gradient(135deg, #FF6B35, #FF8C5A);
  --shadow-card: 0 4px 24px rgba(0,0,0,0.4);
  --shadow-hover: 0 8px 40px rgba(255,107,53,0.25);
  --radius: 12px;
  --radius-sm: 6px;
  --transition: all 0.3s cubic-bezier(0.4,0,0.2,1);
}

/* ---- 重置 ---- */
*, *::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(--primary);
  color: var(--text-main);
  line-height: 1.7;
  overflow-x: hidden;
}
a { color: var(--secondary); text-decoration: none; transition: var(--transition); }
a:hover { color: #FF8C5A; }
img { max-width: 100%; height: auto; display: block; }
ul, ol { list-style: none; }
button { cursor: pointer; border: none; outline: none; }

/* ---- 干扰标签隐藏 ---- */
.wmo49w33 { display: none !important; }

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

/* ============================================================
   HEADER / NAVBAR
   ============================================================ */
.site-header {
  position: sticky;
  top: 0;
  z-index: 1000;
  background: rgba(6,14,26,0.95);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--card-border);
}
.header-inner {
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 70px;
}
.logo-wrap {
  display: flex;
  align-items: center;
  gap: 12px;
  flex-shrink: 0;
}
.logo-wrap img.site-logo {
  height: 44px;
  width: auto;
}
.logo-wrap .brand-name {
  font-size: 1.4rem;
  font-weight: 800;
  color: var(--text-main);
  letter-spacing: 0.05em;
}
.logo-wrap .brand-name span { color: var(--secondary); }

/* 主导航 */
.main-nav { display: flex; align-items: center; gap: 4px; }
.main-nav a {
  color: var(--text-light);
  font-size: 0.9rem;
  font-weight: 500;
  padding: 8px 14px;
  border-radius: var(--radius-sm);
  transition: var(--transition);
  white-space: nowrap;
}
.main-nav a:hover,
.main-nav a.active {
  color: var(--secondary);
  background: rgba(255,107,53,0.1);
}

/* 搜索框 */
.search-bar-wrap {
  display: flex;
  align-items: center;
  gap: 8px;
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: 24px;
  padding: 6px 16px;
  transition: var(--transition);
}
.search-bar-wrap:focus-within {
  border-color: var(--secondary);
  box-shadow: 0 0 0 3px rgba(255,107,53,0.15);
}
.search-bar-wrap input {
  background: none;
  border: none;
  outline: none;
  color: var(--text-main);
  font-size: 0.88rem;
  width: 180px;
}
.search-bar-wrap input::placeholder { color: var(--text-muted); }
.search-bar-wrap button {
  background: none;
  color: var(--text-muted);
  font-size: 1rem;
  padding: 0;
  transition: var(--transition);
}
.search-bar-wrap button:hover { color: var(--secondary); }

/* 汉堡菜单 */
.hamburger { display: none; flex-direction: column; gap: 5px; cursor: pointer; padding: 4px; }
.hamburger span { display: block; width: 24px; height: 2px; background: var(--text-main); border-radius: 2px; transition: var(--transition); }

/* ============================================================
   HERO SECTION
   ============================================================ */
.hero {
  position: relative;
  min-height: 90vh;
  display: flex;
  align-items: center;
  overflow: hidden;
}
.hero-bg {
  position: absolute;
  inset: 0;
  background-image: url('../images/hero_car.jpg');
  background-size: cover;
  background-position: center;
  filter: brightness(0.35);
  transform: scale(1.05);
  transition: transform 8s ease;
}
.hero-bg::after {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(90deg, rgba(6,14,26,0.9) 0%, rgba(6,14,26,0.4) 60%, transparent 100%);
}
.hero-content {
  position: relative;
  z-index: 2;
  max-width: 1280px;
  margin: 0 auto;
  padding: 80px 24px;
  width: 100%;
}
.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: rgba(255,107,53,0.15);
  border: 1px solid rgba(255,107,53,0.4);
  color: var(--secondary);
  font-size: 0.82rem;
  font-weight: 600;
  padding: 6px 16px;
  border-radius: 20px;
  margin-bottom: 24px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}
.hero-badge::before { content: '●'; font-size: 0.6rem; animation: pulse 2s infinite; }
@keyframes pulse { 0%,100%{opacity:1} 50%{opacity:0.3} }

.hero h1 {
  font-size: clamp(2.2rem, 5vw, 4rem);
  font-weight: 900;
  line-height: 1.15;
  margin-bottom: 20px;
  letter-spacing: -0.02em;
}
.hero h1 .brand { color: var(--secondary); }
.hero h1 .sub { display: block; font-size: 0.55em; font-weight: 400; color: var(--text-light); margin-top: 8px; letter-spacing: 0.1em; }

.hero-desc {
  font-size: 1.05rem;
  color: var(--text-light);
  max-width: 560px;
  margin-bottom: 36px;
  line-height: 1.8;
}
.hero-actions { display: flex; gap: 16px; flex-wrap: wrap; }
.btn-primary {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: var(--gradient-orange);
  color: #fff;
  font-size: 0.95rem;
  font-weight: 700;
  padding: 14px 28px;
  border-radius: 8px;
  transition: var(--transition);
  box-shadow: 0 4px 20px rgba(255,107,53,0.4);
}
.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 30px rgba(255,107,53,0.5);
  color: #fff;
}
.btn-outline {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: transparent;
  color: var(--text-main);
  font-size: 0.95rem;
  font-weight: 600;
  padding: 13px 28px;
  border-radius: 8px;
  border: 1.5px solid var(--card-border);
  transition: var(--transition);
}
.btn-outline:hover {
  border-color: var(--secondary);
  color: var(--secondary);
  background: rgba(255,107,53,0.05);
}

.hero-stats {
  display: flex;
  gap: 40px;
  margin-top: 56px;
  flex-wrap: wrap;
}
.hero-stat .num {
  font-size: 2rem;
  font-weight: 900;
  color: var(--secondary);
  line-height: 1;
}
.hero-stat .label {
  font-size: 0.8rem;
  color: var(--text-muted);
  margin-top: 4px;
  letter-spacing: 0.05em;
}

/* ============================================================
   SECTION COMMONS
   ============================================================ */
section { padding: 80px 0; }
.container { max-width: 1280px; margin: 0 auto; padding: 0 24px; }
.section-header { text-align: center; margin-bottom: 56px; }
.section-tag {
  display: inline-block;
  background: rgba(255,107,53,0.12);
  color: var(--secondary);
  font-size: 0.78rem;
  font-weight: 700;
  padding: 4px 14px;
  border-radius: 20px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  margin-bottom: 14px;
}
.section-title {
  font-size: clamp(1.6rem, 3vw, 2.4rem);
  font-weight: 800;
  line-height: 1.2;
  margin-bottom: 14px;
}
.section-title .hl { color: var(--secondary); }
.section-desc {
  font-size: 1rem;
  color: var(--text-muted);
  max-width: 560px;
  margin: 0 auto;
  line-height: 1.8;
}

/* ============================================================
   VIDEO CARDS
   ============================================================ */
.video-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 24px;
}
.video-card {
  background: var(--gradient-card);
  border: 1px solid var(--card-border);
  border-radius: var(--radius);
  overflow: hidden;
  transition: var(--transition);
  cursor: pointer;
}
.video-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-hover);
  border-color: rgba(255,107,53,0.4);
}
.video-thumb {
  position: relative;
  aspect-ratio: 16/9;
  overflow: hidden;
}
.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); }
.play-btn {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(0,0,0,0.3);
  opacity: 0;
  transition: var(--transition);
}
.video-card:hover .play-btn { opacity: 1; }
.play-btn-icon {
  width: 56px;
  height: 56px;
  background: var(--gradient-orange);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 4px 20px rgba(255,107,53,0.5);
  transform: scale(0.8);
  transition: var(--transition);
}
.video-card:hover .play-btn-icon { transform: scale(1); }
.play-btn-icon::after {
  content: '';
  border-left: 18px solid #fff;
  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 8px;
  border-radius: 4px;
}
.video-tag {
  position: absolute;
  top: 8px;
  left: 8px;
  background: var(--secondary);
  color: #fff;
  font-size: 0.7rem;
  font-weight: 700;
  padding: 3px 10px;
  border-radius: 4px;
  letter-spacing: 0.05em;
}
.video-info { padding: 16px; }
.video-info h3 {
  font-size: 0.95rem;
  font-weight: 700;
  margin-bottom: 8px;
  line-height: 1.4;
  color: var(--text-main);
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}
.video-meta {
  display: flex;
  align-items: center;
  gap: 16px;
  font-size: 0.78rem;
  color: var(--text-muted);
}
.video-meta span { display: flex; align-items: center; gap: 4px; }

/* ============================================================
   FEATURE CARDS
   ============================================================ */
.feature-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
  gap: 24px;
}
.feature-card {
  background: var(--gradient-card);
  border: 1px solid var(--card-border);
  border-radius: var(--radius);
  padding: 32px 24px;
  transition: var(--transition);
  position: relative;
  overflow: hidden;
}
.feature-card::before {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 3px;
  background: var(--gradient-orange);
  transform: scaleX(0);
  transform-origin: left;
  transition: var(--transition);
}
.feature-card:hover::before { transform: scaleX(1); }
.feature-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-hover);
  border-color: rgba(255,107,53,0.3);
}
.feature-icon {
  width: 52px;
  height: 52px;
  background: rgba(255,107,53,0.12);
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
  margin-bottom: 20px;
}
.feature-card h3 {
  font-size: 1.05rem;
  font-weight: 700;
  margin-bottom: 10px;
  color: var(--text-main);
}
.feature-card p {
  font-size: 0.88rem;
  color: var(--text-muted);
  line-height: 1.7;
}

/* ============================================================
   EXPERT CARDS
   ============================================================ */
.expert-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 28px;
}
.expert-card {
  background: var(--gradient-card);
  border: 1px solid var(--card-border);
  border-radius: var(--radius);
  padding: 28px;
  text-align: center;
  transition: var(--transition);
}
.expert-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-hover);
}
.expert-avatar {
  width: 80px;
  height: 80px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--secondary), #FF8C5A);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 2rem;
  margin: 0 auto 16px;
  border: 3px solid rgba(255,107,53,0.3);
}
.expert-card h3 { font-size: 1.05rem; font-weight: 700; margin-bottom: 4px; }
.expert-role {
  font-size: 0.8rem;
  color: var(--secondary);
  font-weight: 600;
  margin-bottom: 12px;
  letter-spacing: 0.05em;
}
.expert-desc { font-size: 0.85rem; color: var(--text-muted); margin-bottom: 16px; line-height: 1.6; }
.expert-awards { display: flex; flex-wrap: wrap; gap: 6px; justify-content: center; margin-bottom: 16px; }
.award-tag {
  background: rgba(255,107,53,0.1);
  border: 1px solid rgba(255,107,53,0.25);
  color: var(--secondary);
  font-size: 0.72rem;
  padding: 3px 10px;
  border-radius: 20px;
}
.expert-actions { display: flex; gap: 8px; justify-content: center; }
.btn-sm {
  font-size: 0.8rem;
  padding: 7px 16px;
  border-radius: 6px;
  font-weight: 600;
  transition: var(--transition);
}
.btn-sm-primary {
  background: var(--gradient-orange);
  color: #fff;
}
.btn-sm-outline {
  border: 1px solid var(--card-border);
  color: var(--text-light);
  background: transparent;
}
.btn-sm-outline:hover { border-color: var(--secondary); color: var(--secondary); }

/* ============================================================
   REVIEW CARDS
   ============================================================ */
.review-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 24px;
}
.review-card {
  background: var(--gradient-card);
  border: 1px solid var(--card-border);
  border-radius: var(--radius);
  padding: 24px;
  transition: var(--transition);
}
.review-card:hover { box-shadow: var(--shadow-card); }
.review-stars { color: #FFB800; font-size: 0.9rem; margin-bottom: 12px; }
.review-text { font-size: 0.9rem; color: var(--text-light); line-height: 1.7; margin-bottom: 16px; font-style: italic; }
.reviewer { display: flex; align-items: center; gap: 10px; }
.reviewer-avatar {
  width: 36px; height: 36px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--secondary), #FF8C5A);
  display: flex; align-items: center; justify-content: center;
  font-size: 0.9rem; font-weight: 700; color: #fff; flex-shrink: 0;
}
.reviewer-name { font-size: 0.88rem; font-weight: 700; }
.reviewer-label { font-size: 0.75rem; color: var(--text-muted); }

/* ============================================================
   FAQ
   ============================================================ */
.faq-list { max-width: 800px; margin: 0 auto; }
.faq-item {
  border: 1px solid var(--card-border);
  border-radius: var(--radius);
  margin-bottom: 12px;
  overflow: hidden;
  transition: var(--transition);
}
.faq-item:hover { border-color: rgba(255,107,53,0.3); }
.faq-q {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 18px 24px;
  cursor: pointer;
  background: var(--gradient-card);
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--text-main);
  transition: var(--transition);
  user-select: none;
}
.faq-q:hover { color: var(--secondary); }
.faq-q .arrow {
  width: 24px; height: 24px;
  border: 1.5px solid var(--card-border);
  border-radius: 50%;
  display: flex; align-items: center; justify-content: center;
  font-size: 0.7rem;
  color: var(--text-muted);
  transition: var(--transition);
  flex-shrink: 0;
}
.faq-item.open .faq-q .arrow { transform: rotate(180deg); border-color: var(--secondary); color: var(--secondary); }
.faq-a {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.4s ease, padding 0.3s ease;
  background: var(--card-bg);
  font-size: 0.9rem;
  color: var(--text-muted);
  line-height: 1.8;
  padding: 0 24px;
}
.faq-item.open .faq-a { max-height: 300px; padding: 16px 24px; }

/* ============================================================
   PARTNER LOGOS
   ============================================================ */
.partner-grid {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  justify-content: center;
  align-items: center;
}
.partner-item {
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: var(--radius-sm);
  padding: 16px 28px;
  font-size: 0.9rem;
  font-weight: 700;
  color: var(--text-muted);
  transition: var(--transition);
  letter-spacing: 0.05em;
}
.partner-item:hover { border-color: var(--secondary); color: var(--secondary); }

/* ============================================================
   CONTACT SECTION
   ============================================================ */
.contact-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 40px;
  align-items: start;
}
.contact-info h3 { font-size: 1.3rem; font-weight: 700; margin-bottom: 20px; }
.contact-item {
  display: flex;
  align-items: flex-start;
  gap: 14px;
  margin-bottom: 20px;
  padding: 16px;
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: var(--radius-sm);
}
.contact-icon {
  width: 40px; height: 40px;
  background: rgba(255,107,53,0.12);
  border-radius: 8px;
  display: flex; align-items: center; justify-content: center;
  font-size: 1.1rem;
  flex-shrink: 0;
}
.contact-item-text .label { font-size: 0.78rem; color: var(--text-muted); margin-bottom: 2px; }
.contact-item-text .value { font-size: 0.92rem; font-weight: 600; color: var(--text-main); }
.qr-row { display: flex; gap: 24px; margin-top: 24px; }
.qr-box { text-align: center; }
.qr-box img { width: 120px; height: 120px; border-radius: 8px; margin: 0 auto 8px; }
.qr-box p { font-size: 0.78rem; color: var(--text-muted); }

/* ============================================================
   SHARE BAR
   ============================================================ */
.share-bar {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
  justify-content: center;
  margin-top: 24px;
}
.share-btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 20px;
  border-radius: 8px;
  font-size: 0.85rem;
  font-weight: 600;
  transition: var(--transition);
  border: 1px solid var(--card-border);
  background: var(--card-bg);
  color: var(--text-light);
}
.share-btn:hover { transform: translateY(-2px); box-shadow: var(--shadow-card); color: #fff; }
.share-btn.weixin:hover { background: #07C160; border-color: #07C160; }
.share-btn.weibo:hover { background: #E6162D; border-color: #E6162D; }
.share-btn.douyin:hover { background: #161823; border-color: #FE2C55; }
.share-btn.bilibili:hover { background: #00A1D6; border-color: #00A1D6; }

/* ============================================================
   FOOTER
   ============================================================ */
.site-footer {
  background: var(--dark);
  border-top: 1px solid var(--card-border);
  padding: 60px 0 0;
}
.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 40px;
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 24px 40px;
}
.footer-brand .logo-wrap { margin-bottom: 16px; }
.footer-brand p { font-size: 0.88rem; color: var(--text-muted); line-height: 1.7; max-width: 280px; }
.footer-col h4 {
  font-size: 0.9rem;
  font-weight: 700;
  color: var(--text-main);
  margin-bottom: 16px;
  letter-spacing: 0.05em;
  text-transform: uppercase;
}
.footer-col ul li { margin-bottom: 10px; }
.footer-col ul li a { font-size: 0.85rem; color: var(--text-muted); transition: var(--transition); }
.footer-col ul li a:hover { color: var(--secondary); padding-left: 4px; }
.footer-bottom {
  border-top: 1px solid var(--card-border);
  padding: 20px 24px;
  max-width: 1280px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 12px;
}
.footer-bottom p { font-size: 0.82rem; color: var(--text-muted); }
.footer-bottom a { color: var(--text-muted); }
.footer-bottom a:hover { color: var(--secondary); }
.update-time { font-size: 0.78rem; color: var(--text-muted); }

/* ============================================================
   BREADCRUMB
   ============================================================ */
.breadcrumb {
  padding: 14px 0;
  font-size: 0.82rem;
  color: var(--text-muted);
}
.breadcrumb a { color: var(--text-muted); }
.breadcrumb a:hover { color: var(--secondary); }
.breadcrumb span { margin: 0 6px; }

/* ============================================================
   AI SECTION
   ============================================================ */
.ai-section { background: linear-gradient(135deg, #060E1A 0%, #0D1A2E 100%); }
.ai-grid {
  display: grid;
  grid-template-columns: 1fr 1fr 1fr;
  gap: 24px;
}
.ai-card {
  background: linear-gradient(145deg, #0F1E35, #0A1628);
  border: 1px solid rgba(255,107,53,0.2);
  border-radius: var(--radius);
  padding: 28px;
  position: relative;
  overflow: hidden;
}
.ai-card::after {
  content: '';
  position: absolute;
  top: -50%;
  right: -50%;
  width: 200%;
  height: 200%;
  background: radial-gradient(circle, rgba(255,107,53,0.05) 0%, transparent 60%);
  pointer-events: none;
}
.ai-card h3 { font-size: 1rem; font-weight: 700; margin-bottom: 10px; color: var(--text-main); }
.ai-card p { font-size: 0.85rem; color: var(--text-muted); line-height: 1.7; }
.ai-badge {
  display: inline-block;
  background: linear-gradient(135deg, rgba(255,107,53,0.2), rgba(255,107,53,0.05));
  border: 1px solid rgba(255,107,53,0.3);
  color: var(--secondary);
  font-size: 0.7rem;
  font-weight: 700;
  padding: 3px 10px;
  border-radius: 20px;
  margin-bottom: 14px;
  letter-spacing: 0.08em;
}

/* ============================================================
   HOW TO JOIN
   ============================================================ */
.join-steps {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  gap: 24px;
  counter-reset: step;
}
.join-step {
  background: var(--gradient-card);
  border: 1px solid var(--card-border);
  border-radius: var(--radius);
  padding: 28px 20px;
  text-align: center;
  position: relative;
  counter-increment: step;
}
.join-step::before {
  content: counter(step);
  position: absolute;
  top: -14px;
  left: 50%;
  transform: translateX(-50%);
  width: 28px; height: 28px;
  background: var(--gradient-orange);
  border-radius: 50%;
  display: flex; align-items: center; justify-content: center;
  font-size: 0.8rem; font-weight: 800; color: #fff;
  line-height: 28px;
  text-align: center;
}
.join-step-icon { font-size: 2rem; margin-bottom: 14px; }
.join-step h4 { font-size: 0.95rem; font-weight: 700; margin-bottom: 8px; }
.join-step p { font-size: 0.82rem; color: var(--text-muted); line-height: 1.6; }

/* ============================================================
   INNER PAGE HERO
   ============================================================ */
.inner-hero {
  padding: 60px 0 40px;
  background: linear-gradient(135deg, var(--dark) 0%, var(--primary) 100%);
  border-bottom: 1px solid var(--card-border);
}
.inner-hero h1 { font-size: clamp(1.8rem, 3vw, 2.8rem); font-weight: 800; margin-bottom: 12px; }
.inner-hero p { font-size: 1rem; color: var(--text-muted); max-width: 600px; }

/* ============================================================
   RESPONSIVE
   ============================================================ */
@media (max-width: 1024px) {
  .footer-grid { grid-template-columns: 1fr 1fr; }
  .contact-grid { grid-template-columns: 1fr; }
  .ai-grid { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 768px) {
  .main-nav { display: none; position: absolute; top: 70px; left: 0; right: 0; background: rgba(6,14,26,0.98); flex-direction: column; padding: 16px; gap: 4px; border-bottom: 1px solid var(--card-border); }
  .main-nav.open { display: flex; }
  .hamburger { display: flex; }
  .search-bar-wrap { display: none; }
  .hero-stats { gap: 24px; }
  .footer-grid { grid-template-columns: 1fr; }
  .ai-grid { grid-template-columns: 1fr; }
  .video-grid { grid-template-columns: 1fr 1fr; }
  .expert-grid { grid-template-columns: 1fr 1fr; }
  section { padding: 56px 0; }
}
@media (max-width: 480px) {
  .video-grid { grid-template-columns: 1fr; }
  .expert-grid { grid-template-columns: 1fr; }
  .hero h1 { font-size: 1.8rem; }
  .hero-actions { flex-direction: column; }
  .btn-primary, .btn-outline { width: 100%; justify-content: center; }
  .qr-row { justify-content: center; }
}

/* ============================================================
   UTILITY
   ============================================================ */
.text-center { text-align: center; }
.mt-8 { margin-top: 8px; }
.mt-16 { margin-top: 16px; }
.mt-24 { margin-top: 24px; }
.mt-40 { margin-top: 40px; }
.mb-24 { margin-bottom: 24px; }
.divider { height: 1px; background: var(--card-border); margin: 40px 0; }
.tag-list { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 12px; }
.tag {
  background: rgba(200,216,232,0.08);
  border: 1px solid var(--card-border);
  color: var(--text-muted);
  font-size: 0.75rem;
  padding: 4px 12px;
  border-radius: 20px;
}
.tag:hover { border-color: var(--secondary); color: var(--secondary); cursor: pointer; }
.lazy { opacity: 0; transition: opacity 0.5s ease; }
.lazy.loaded { opacity: 1; }

/* ============================================================
   STATS GRID（AI赋能页、关于页等使用）
   ============================================================ */
.stats-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
  margin-top: 40px;
}
.stat-item {
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: var(--radius);
  padding: 32px 20px;
  text-align: center;
  transition: var(--transition);
}
.stat-item:hover {
  border-color: var(--secondary);
  box-shadow: var(--shadow-hover);
}
.stat-num {
  font-size: clamp(2rem, 4vw, 3rem);
  font-weight: 900;
  color: var(--secondary);
  line-height: 1;
  margin-bottom: 8px;
}
.stat-num span {
  font-size: 0.6em;
  font-weight: 700;
}
.stat-label {
  font-size: 0.85rem;
  color: var(--text-muted);
}
@media (max-width: 768px) {
  .stats-grid { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 480px) {
  .stats-grid { grid-template-columns: 1fr 1fr; gap: 12px; }
}

/* ============================================================
   AI HERO（AI赋能页专属英雄区）
   ============================================================ */
.ai-hero {
  position: relative;
  overflow: hidden;
}
.ai-hero::before {
  content: '';
  position: absolute;
  top: -50%;
  right: -10%;
  width: 500px;
  height: 500px;
  background: radial-gradient(circle, rgba(255,107,53,0.08) 0%, transparent 70%);
  pointer-events: none;
}

/* ============================================================
   BREADCRUMB（面包屑，内页使用）
   ============================================================ */
.breadcrumb {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.85rem;
  color: var(--text-muted);
  padding: 16px 0;
}
.breadcrumb a { color: var(--text-muted); }
.breadcrumb a:hover { color: var(--secondary); }
.breadcrumb span { color: var(--text-muted); }
.breadcrumb span:last-child { color: var(--secondary); }