/* ==========================================
   91修车改装视频社区 - 原创样式表
   配色方案：深空灰 + 赛车红 + 金属银
   ========================================== */

/* === 基础重置与变量 === */
:root {
  --bg-primary: #0c0e14;
  --bg-section: #111520;
  --bg-card: #181c28;
  --bg-card-hover: #1e2436;
  --text-primary: #e8eaf0;
  --text-secondary: #9ba3b5;
  --text-muted: #6b7280;
  --accent-red: #e63946;
  --accent-red-dark: #c1121f;
  --accent-gold: #d4a843;
  --accent-silver: #b0b8c8;
  --border-color: #2a3042;
  --radius: 10px;
  --radius-sm: 6px;
  --shadow: 0 4px 24px rgba(0,0,0,0.35);
  --shadow-hover: 0 8px 40px rgba(230,57,70,0.15);
  --transition: all 0.3s ease;
  --max-width: 1240px;
}

*, *::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-primary);
  color: var(--text-primary);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

a { color: var(--accent-red); text-decoration: none; transition: var(--transition); }
a:hover { color: var(--accent-gold); }

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

.container { max-width: var(--max-width); margin: 0 auto; padding: 0 24px; }

/* === 头部导航 === */
.site-header {
  position: fixed; top: 0; left: 0; right: 0; z-index: 1000;
  background: rgba(12,14,20,0.92);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border-color);
}

.header-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
  display: flex;
  align-items: center;
  height: 68px;
  gap: 24px;
}

.logo-link img { height: 36px; width: auto; }

.main-nav {
  display: flex;
  gap: 4px;
  flex: 1;
}

.main-nav a {
  color: var(--text-secondary);
  padding: 8px 14px;
  border-radius: var(--radius-sm);
  font-size: 0.94rem;
  font-weight: 500;
  white-space: nowrap;
}

.main-nav a:hover, .main-nav a.nav-active {
  color: #fff;
  background: rgba(230,57,70,0.12);
}

.main-nav a.nav-active { color: var(--accent-red); }

.header-search { margin-left: auto; }

.search-form {
  display: flex;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 20px;
  overflow: hidden;
}

.search-form input {
  background: transparent;
  border: none;
  color: var(--text-primary);
  padding: 7px 14px;
  font-size: 0.88rem;
  width: 180px;
  outline: none;
}

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

.search-form button {
  background: transparent;
  border: none;
  color: var(--text-secondary);
  padding: 7px 12px;
  cursor: pointer;
  font-size: 1rem;
}

.mobile-toggle {
  display: none;
  background: none;
  border: none;
  color: var(--text-primary);
  font-size: 1.5rem;
  cursor: pointer;
}

/* === Hero Banner === */
.hero-banner {
  position: relative;
  min-height: 92vh;
  display: flex;
  align-items: center;
  overflow: hidden;
  margin-top: 68px;
}

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

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

.hero-overlay {
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, rgba(12,14,20,0.88) 0%, rgba(12,14,20,0.55) 50%, rgba(12,14,20,0.75) 100%);
}

.hero-content {
  position: relative;
  z-index: 2;
  max-width: 720px;
  padding: 60px 40px;
}

.hero-content h1 {
  font-size: 3.2rem;
  font-weight: 800;
  line-height: 1.15;
  margin-bottom: 12px;
  background: linear-gradient(135deg, #fff 0%, var(--accent-gold) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-content h2 {
  font-size: 1.15rem;
  font-weight: 400;
  color: var(--accent-silver);
  margin-bottom: 20px;
}

.hero-content p {
  font-size: 1rem;
  color: var(--text-secondary);
  margin-bottom: 28px;
  line-height: 1.8;
}

.hero-btns {
  display: flex;
  gap: 16px;
  margin-bottom: 40px;
}

.btn-primary {
  display: inline-block;
  background: linear-gradient(135deg, var(--accent-red) 0%, var(--accent-red-dark) 100%);
  color: #fff;
  padding: 13px 32px;
  border-radius: 30px;
  font-weight: 600;
  font-size: 0.95rem;
  transition: var(--transition);
  box-shadow: 0 4px 20px rgba(230,57,70,0.3);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 28px rgba(230,57,70,0.45);
  color: #fff;
}

.btn-outline {
  display: inline-block;
  border: 2px solid var(--accent-silver);
  color: var(--accent-silver);
  padding: 11px 30px;
  border-radius: 30px;
  font-weight: 600;
  font-size: 0.95rem;
  transition: var(--transition);
}

.btn-outline:hover {
  border-color: var(--accent-gold);
  color: var(--accent-gold);
  transform: translateY(-2px);
}

.hero-stats {
  display: flex;
  gap: 48px;
}

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

.stat-num {
  display: block;
  font-size: 2rem;
  font-weight: 800;
  color: var(--accent-gold);
}

.stat-label {
  font-size: 0.85rem;
  color: var(--text-muted);
}

/* === 通用 Section === */
.section {
  padding: 80px 0;
}

.section-dark {
  background: var(--bg-section);
}

.section-head {
  text-align: center;
  margin-bottom: 48px;
}

.section-head h2 {
  font-size: 2rem;
  font-weight: 700;
  margin-bottom: 8px;
  color: var(--text-primary);
}

.section-head h3 {
  font-size: 1rem;
  font-weight: 400;
  color: var(--text-muted);
}

/* === 视频卡片网格 === */
.video-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

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

.video-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-hover);
  border-color: rgba(230,57,70,0.3);
}

.video-thumb {
  position: relative;
  aspect-ratio: 16/9;
  overflow: hidden;
  cursor: pointer;
}

.video-thumb img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.4s ease;
}

.video-card:hover .video-thumb img {
  transform: scale(1.05);
}

.play-btn {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%) scale(0.8);
  width: 56px;
  height: 56px;
  background: rgba(230,57,70,0.85);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.4rem;
  color: #fff;
  opacity: 0;
  transition: var(--transition);
}

.video-card:hover .play-btn {
  opacity: 1;
  transform: translate(-50%, -50%) scale(1);
}

.video-duration {
  position: absolute;
  bottom: 8px;
  right: 8px;
  background: rgba(0,0,0,0.75);
  color: #fff;
  padding: 2px 8px;
  border-radius: 4px;
  font-size: 0.78rem;
  font-weight: 600;
}

.video-tag {
  position: absolute;
  top: 8px;
  left: 8px;
  background: var(--accent-red);
  color: #fff;
  padding: 2px 10px;
  border-radius: 4px;
  font-size: 0.75rem;
  font-weight: 600;
}

.video-info {
  padding: 16px;
}

.video-info h4 {
  font-size: 0.95rem;
  font-weight: 600;
  margin-bottom: 8px;
  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: 0.8rem;
  color: var(--text-muted);
}

/* === 模块卡片网格 === */
.module-grid-4 {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}

.module-grid-3 {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}

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

.mod-card:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-hover);
  border-color: rgba(230,57,70,0.25);
}

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

.mod-card h4 {
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: 8px;
  color: var(--text-primary);
}

.mod-card p {
  font-size: 0.88rem;
  color: var(--text-secondary);
  line-height: 1.6;
}

/* === 专家团队 === */
.expert-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
}

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

.expert-card:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-hover);
}

.expert-card img {
  width: 100px;
  height: 100px;
  border-radius: 50%;
  object-fit: cover;
  margin: 0 auto 16px;
  border: 3px solid var(--accent-red);
}

.expert-card h4 {
  font-size: 1.1rem;
  font-weight: 700;
  margin-bottom: 4px;
}

.expert-card .role {
  font-size: 0.82rem;
  color: var(--accent-gold);
  margin-bottom: 10px;
}

.expert-card p {
  font-size: 0.85rem;
  color: var(--text-secondary);
  margin-bottom: 14px;
  line-height: 1.6;
}

.btn-sm {
  display: inline-block;
  padding: 6px 18px;
  border: 1px solid var(--accent-red);
  color: var(--accent-red);
  border-radius: 20px;
  font-size: 0.82rem;
  transition: var(--transition);
}

.btn-sm:hover {
  background: var(--accent-red);
  color: #fff;
}

/* === 荣誉资质 === */
.honor-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}

.honor-item {
  text-align: center;
  padding: 28px 16px;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius);
  transition: var(--transition);
}

.honor-item:hover {
  border-color: var(--accent-gold);
}

.honor-icon {
  font-size: 2.4rem;
  margin-bottom: 12px;
}

.honor-item h4 {
  font-size: 1rem;
  margin-bottom: 6px;
  color: var(--accent-gold);
}

.honor-item p {
  font-size: 0.85rem;
  color: var(--text-secondary);
}

/* === AI赋能图片 === */
.ai-img-wrap {
  margin-top: 36px;
  border-radius: var(--radius);
  overflow: hidden;
  border: 1px solid var(--border-color);
}

.ai-img-wrap img {
  width: 100%;
  display: block;
}

/* === 合作品牌 === */
.partner-grid {
  display: grid;
  grid-template-columns: repeat(6, 1fr);
  gap: 16px;
}

.partner-item {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius);
  padding: 20px;
  text-align: center;
  font-weight: 600;
  color: var(--accent-silver);
  font-size: 0.95rem;
  transition: var(--transition);
}

.partner-item:hover {
  border-color: var(--accent-gold);
  color: var(--accent-gold);
}

/* === 媒体报道 === */
.media-list {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.media-item {
  display: flex;
  align-items: center;
  gap: 20px;
  padding: 16px 20px;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  transition: var(--transition);
}

.media-item:hover { border-color: var(--accent-red); }

.media-item .source {
  background: var(--accent-red);
  color: #fff;
  padding: 3px 12px;
  border-radius: 4px;
  font-size: 0.8rem;
  font-weight: 600;
  white-space: nowrap;
}

.media-item .title {
  flex: 1;
  font-size: 0.95rem;
  color: var(--text-primary);
}

.media-item .date {
  font-size: 0.82rem;
  color: var(--text-muted);
  white-space: nowrap;
}

/* === How-To步骤 === */
.howto-steps {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}

.step-card {
  text-align: center;
  padding: 28px 16px;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius);
  position: relative;
  transition: var(--transition);
}

.step-card:hover {
  border-color: var(--accent-red);
}

.step-num {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--accent-red), var(--accent-red-dark));
  color: #fff;
  font-size: 1.2rem;
  font-weight: 800;
  margin-bottom: 14px;
}

.step-card h4 {
  font-size: 1rem;
  margin-bottom: 8px;
}

.step-card p {
  font-size: 0.85rem;
  color: var(--text-secondary);
}

/* === FAQ === */
.faq-list {
  max-width: 800px;
  margin: 0 auto;
}

.faq-item {
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  margin-bottom: 10px;
  overflow: hidden;
  background: var(--bg-card);
}

.faq-q {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 16px 20px;
  cursor: pointer;
  font-weight: 600;
  font-size: 0.95rem;
  transition: var(--transition);
}

.faq-q:hover { color: var(--accent-red); }

.faq-q .arrow {
  font-size: 0.7rem;
  transition: transform 0.3s ease;
}

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

.faq-a {
  padding: 0 20px;
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.35s ease, padding 0.35s ease;
  font-size: 0.9rem;
  color: var(--text-secondary);
  line-height: 1.7;
}

.faq-item.open .faq-a {
  padding: 0 20px 16px;
  max-height: 300px;
}

/* === 用户评价 === */
.review-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}

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

.review-card:hover {
  border-color: var(--accent-gold);
}

.review-header {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 10px;
}

.review-avatar {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--accent-red), var(--accent-red-dark));
  color: #fff;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 0.95rem;
}

.review-name { font-weight: 600; font-size: 0.92rem; }
.review-date { font-size: 0.78rem; color: var(--text-muted); }

.review-stars {
  color: var(--accent-gold);
  font-size: 0.9rem;
  margin-bottom: 8px;
}

.review-text {
  font-size: 0.88rem;
  color: var(--text-secondary);
  line-height: 1.65;
}

/* === 分享栏 === */
.share-bar {
  display: flex;
  justify-content: center;
  gap: 16px;
  flex-wrap: wrap;
}

.share-btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 10px 24px;
  border-radius: 24px;
  font-size: 0.9rem;
  font-weight: 500;
  color: #fff;
  transition: var(--transition);
}

.share-btn.wechat { background: #07c160; }
.share-btn.weibo { background: #e6162d; }
.share-btn.douyin { background: #161823; border: 1px solid #333; }
.share-btn.bilibili { background: #00a1d6; }

.share-btn:hover { transform: translateY(-2px); opacity: 0.9; color: #fff; }

/* === 页脚 === */
.site-footer {
  background: var(--bg-section);
  border-top: 1px solid var(--border-color);
  padding: 60px 0 0;
}

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

.footer-brand img { height: 36px; width: auto; margin-bottom: 14px; }

.footer-brand p {
  font-size: 0.88rem;
  color: var(--text-secondary);
  line-height: 1.7;
}

.footer-col h4 {
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: 14px;
  color: var(--text-primary);
}

.footer-col a {
  display: block;
  font-size: 0.88rem;
  color: var(--text-secondary);
  margin-bottom: 8px;
}

.footer-col a:hover { color: var(--accent-red); }

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

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

.qr-item img {
  border-radius: var(--radius-sm);
  margin-bottom: 4px;
}

.qr-item span {
  font-size: 0.78rem;
  color: var(--text-muted);
}

.footer-bottom {
  border-top: 1px solid var(--border-color);
  padding: 20px 0;
  text-align: center;
}

.footer-bottom p {
  font-size: 0.82rem;
  color: var(--text-muted);
}

/* === 响应式 === */
@media (max-width: 1024px) {
  .module-grid-4, .expert-grid, .honor-grid, .howto-steps {
    grid-template-columns: repeat(2, 1fr);
  }
  .video-grid { grid-template-columns: repeat(2, 1fr); }
  .partner-grid { grid-template-columns: repeat(3, 1fr); }
  .footer-grid { grid-template-columns: 1fr 1fr; }
}

@media (max-width: 768px) {
  .main-nav { display: none; }
  .header-search { display: none; }
  .mobile-toggle { display: block; }

  .main-nav.open {
    display: flex;
    flex-direction: column;
    position: absolute;
    top: 68px;
    left: 0;
    right: 0;
    background: var(--bg-primary);
    border-bottom: 1px solid var(--border-color);
    padding: 16px;
    gap: 4px;
  }

  .hero-banner { min-height: 80vh; }
  .hero-content { padding: 40px 24px; }
  .hero-content h1 { font-size: 2rem; }
  .hero-content h2 { font-size: 1rem; }
  .hero-stats { gap: 24px; }
  .stat-num { font-size: 1.5rem; }

  .section { padding: 50px 0; }
  .section-head h2 { font-size: 1.5rem; }

  .video-grid, .module-grid-4, .module-grid-3, .expert-grid, .honor-grid, .howto-steps, .review-grid {
    grid-template-columns: 1fr;
  }

  .partner-grid { grid-template-columns: repeat(2, 1fr); }
  .footer-grid { grid-template-columns: 1fr; gap: 24px; }
  .hero-btns { flex-direction: column; }
}

@media (max-width: 480px) {
  .hero-content h1 { font-size: 1.6rem; }
  .hero-stats { flex-direction: column; gap: 12px; }
}