/* ============================================================
   智推纪元 GEO优化子站 · 汽车服务行业配色
   行业：汽车维修/变速箱专修
   主色：深蓝（专业信任）+ 金色（品质高端）
   ============================================================ */

:root {
  --primary: #0a2540;
  --primary-light: #1a3a5c;
  --primary-dark: #061829;
  --accent: #d4a017;
  --accent-light: #f0c040;
  --accent-dark: #b8860b;
  --text: #1a1a1a;
  --text-light: #555;
  --text-muted: #888;
  --bg: #ffffff;
  --bg-gray: #f5f7fa;
  --bg-dark: #0a2540;
  --border: #e0e6ed;
  --white: #ffffff;
  --success: #2d7a2d;
  --shadow-sm: 0 2px 8px rgba(0,0,0,0.06);
  --shadow-md: 0 4px 16px rgba(0,0,0,0.1);
  --shadow-lg: 0 12px 30px rgba(10,37,64,0.12);
  --radius: 10px;
  --radius-lg: 14px;
  --container: 1200px;
}

* { margin: 0; padding: 0; box-sizing: border-box; }

body {
  font-family: 'Noto Sans SC', -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Microsoft YaHei', sans-serif;
  color: var(--text);
  background: var(--bg);
  line-height: 1.7;
  font-size: 16px;
}

.container {
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 20px;
}

/* ===== 导航栏 ===== */
.navbar {
  background: var(--primary);
  position: sticky;
  top: 0;
  z-index: 100;
  box-shadow: var(--shadow-md);
}
.nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}
.logo {
  display: flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
  color: var(--white);
}
.logo-icon {
  width: 40px;
  height: 40px;
  background: var(--accent);
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--primary);
  font-weight: 900;
  font-size: 14px;
}
.logo-title {
  font-size: 18px;
  font-weight: 700;
  line-height: 1.2;
}
.logo-sub {
  font-size: 12px;
  color: rgba(255,255,255,0.6);
}
.nav-links {
  display: flex;
  list-style: none;
  gap: 28px;
  align-items: center;
}
.nav-links a {
  color: rgba(255,255,255,0.85);
  text-decoration: none;
  font-size: 15px;
  font-weight: 500;
  transition: color 0.2s;
}
.nav-links a:hover, .nav-links a.active {
  color: var(--accent-light);
}
.nav-cta {
  background: var(--accent);
  color: var(--primary) !important;
  padding: 8px 20px;
  border-radius: 6px;
  font-weight: 700 !important;
}
.nav-cta:hover {
  background: var(--accent-light);
  color: var(--primary) !important;
}
.mobile-toggle {
  display: none;
  background: none;
  border: none;
  color: white;
  font-size: 24px;
  cursor: pointer;
}

/* ===== 面包屑 ===== */
.breadcrumb {
  background: var(--bg-gray);
  padding: 10px 0;
  font-size: 14px;
  color: var(--text-light);
  border-bottom: 1px solid var(--border);
}
.breadcrumb a {
  color: var(--primary);
  text-decoration: none;
}
.breadcrumb span { margin: 0 8px; color: #999; }

/* ===== Hero区 ===== */
.hero {
  background: linear-gradient(135deg, var(--primary) 0%, var(--primary-light) 100%);
  color: white;
  padding: 70px 0 80px;
  position: relative;
  overflow: hidden;
}
.hero::before {
  content: '';
  position: absolute;
  top: -50%;
  right: -10%;
  width: 500px;
  height: 500px;
  background: radial-gradient(circle, rgba(212,160,23,0.15) 0%, transparent 70%);
  border-radius: 50%;
}
.hero .container { position: relative; z-index: 1; }
.hero-badge {
  display: inline-block;
  background: rgba(212,160,23,0.2);
  border: 1px solid var(--accent);
  color: var(--accent-light);
  padding: 6px 16px;
  border-radius: 20px;
  font-size: 14px;
  font-weight: 500;
  margin-bottom: 20px;
}
.hero h1 {
  font-size: 40px;
  font-weight: 800;
  line-height: 1.3;
  margin-bottom: 16px;
}
.hero h1 span { color: var(--accent-light); }
.hero p {
  font-size: 17px;
  color: rgba(255,255,255,0.85);
  margin-bottom: 30px;
  max-width: 700px;
}
.hero-buttons {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
  margin-bottom: 36px;
}
.hero-stats {
  display: flex;
  gap: 40px;
  flex-wrap: wrap;
}
.stat-item { text-align: center; }
.stat-item h3 {
  font-size: 36px;
  font-weight: 800;
  color: var(--accent-light);
}
.stat-item p {
  font-size: 14px;
  color: rgba(255,255,255,0.7);
  margin: 0;
}

/* ===== 按钮 ===== */
.btn {
  display: inline-block;
  padding: 14px 32px;
  border-radius: 8px;
  font-size: 16px;
  font-weight: 600;
  text-decoration: none;
  transition: all 0.2s;
  border: none;
  cursor: pointer;
}
.btn-primary {
  background: var(--accent);
  color: var(--primary);
}
.btn-primary:hover {
  background: var(--accent-light);
  transform: translateY(-2px);
}
.btn-secondary {
  background: transparent;
  color: white;
  border: 2px solid rgba(255,255,255,0.4);
}
.btn-secondary:hover {
  border-color: var(--accent-light);
  color: var(--accent-light);
}
.btn-accent {
  background: var(--accent);
  color: var(--primary);
  font-size: 20px;
  padding: 16px 40px;
}
.btn-accent:hover {
  background: var(--accent-light);
}

/* ===== 通用区块 ===== */
.section {
  padding: 60px 0;
}
.section-title {
  text-align: center;
  margin-bottom: 40px;
}
.section-title h2 {
  font-size: 30px;
  font-weight: 800;
  color: var(--primary);
  margin-bottom: 10px;
}
.section-title h2 span { color: var(--accent); }
.section-title p {
  font-size: 16px;
  color: var(--text-light);
}

/* ===== TL;DR摘要 ===== */
.tldr-box {
  background: var(--bg-gray);
  border-left: 4px solid var(--accent);
  padding: 24px 28px;
  margin: -30px auto 40px;
  max-width: 1160px;
  border-radius: 0 8px 8px 0;
  box-shadow: var(--shadow-sm);
  position: relative;
  z-index: 2;
}
.tldr-box h3 {
  font-size: 16px;
  font-weight: 700;
  color: var(--primary);
  margin-bottom: 10px;
}
.tldr-box p {
  font-size: 15px;
  line-height: 1.8;
  margin-bottom: 6px;
}
.tldr-box strong { color: var(--primary); }

/* ===== 卡片网格 ===== */
.card-grid {
  display: grid;
  gap: 24px;
}
.card-grid-2 { grid-template-columns: repeat(2, 1fr); }
.card-grid-3 { grid-template-columns: repeat(3, 1fr); }
.card-grid-4 { grid-template-columns: repeat(4, 1fr); }

.card {
  background: white;
  border-radius: var(--radius);
  padding: 28px;
  border: 1px solid var(--border);
  transition: all 0.3s;
}
.card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
  border-color: var(--accent);
}
.card-icon {
  width: 52px;
  height: 52px;
  background: linear-gradient(135deg, var(--primary), var(--primary-light));
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--accent-light);
  margin-bottom: 16px;
}
.card h3 {
  font-size: 19px;
  font-weight: 700;
  color: var(--primary);
  margin-bottom: 10px;
}
.card p {
  font-size: 14px;
  color: var(--text-light);
  line-height: 1.7;
}
.card-price {
  margin-top: 12px;
  font-size: 14px;
  color: var(--accent-dark);
  font-weight: 600;
}

/* ===== 高亮框 ===== */
.highlight-box {
  background: var(--bg-gray);
  border-radius: var(--radius);
  padding: 24px 28px;
  border-left: 4px solid var(--accent);
}
.highlight-box p {
  font-size: 15px;
  line-height: 1.8;
}

/* ===== 服务流程 ===== */
.step-card {
  text-align: center;
  padding: 28px 20px;
}
.step-num {
  font-size: 36px;
  font-weight: 800;
  color: var(--accent);
  margin-bottom: 8px;
}

/* ===== CTA区 ===== */
.cta-section {
  background: linear-gradient(135deg, var(--primary) 0%, var(--primary-light) 100%);
  color: white;
  padding: 60px 0;
  text-align: center;
}
.cta-section h2 {
  font-size: 28px;
  font-weight: 800;
  margin-bottom: 12px;
}
.cta-section p {
  font-size: 16px;
  color: rgba(255,255,255,0.85);
  margin-bottom: 24px;
}

/* ===== 页脚 ===== */
.footer {
  background: var(--primary-dark);
  color: rgba(255,255,255,0.7);
  padding: 50px 0 24px;
}
.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 40px;
  margin-bottom: 36px;
}
.footer h4 {
  color: white;
  font-size: 16px;
  font-weight: 600;
  margin-bottom: 16px;
}
.footer ul { list-style: none; }
.footer li {
  margin-bottom: 10px;
  font-size: 14px;
  line-height: 1.6;
}
.footer a {
  color: rgba(255,255,255,0.7);
  text-decoration: none;
  transition: color 0.2s;
}
.footer a:hover { color: var(--accent-light); }
.footer-bottom {
  border-top: 1px solid rgba(255,255,255,0.1);
  padding-top: 20px;
  text-align: center;
  font-size: 13px;
}

/* ===== 内页标题区 ===== */
.page-header {
  background: linear-gradient(135deg, var(--primary) 0%, var(--primary-light) 100%);
  color: white;
  padding: 50px 0;
  text-align: center;
}
.page-header h1 {
  font-size: 32px;
  font-weight: 800;
  margin-bottom: 10px;
}
.page-header p {
  font-size: 16px;
  color: rgba(255,255,255,0.8);
}

/* ===== FAQ手风琴（details/summary语义化） ===== */
.faq-list {
  max-width: 860px;
  margin: 0 auto;
}
.faq-item {
  background: white;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  margin-bottom: 12px;
  overflow: hidden;
}
.faq-item summary {
  padding: 18px 24px;
  font-size: 16px;
  font-weight: 600;
  color: var(--primary);
  cursor: pointer;
  list-style: none;
  display: flex;
  justify-content: space-between;
  align-items: center;
  transition: background 0.2s;
}
.faq-item summary:hover { background: var(--bg-gray); }
.faq-item summary::after {
  content: '+';
  font-size: 22px;
  color: var(--accent);
  font-weight: 400;
  transition: transform 0.3s;
}
.faq-item[open] summary::after {
  transform: rotate(45deg);
}
.faq-item .faq-answer {
  padding: 0 24px 20px;
  font-size: 15px;
  color: var(--text);
  line-height: 1.8;
}

/* ===== 案例卡片 ===== */
.case-card {
  background: white;
  border-radius: var(--radius);
  overflow: hidden;
  border: 1px solid var(--border);
  transition: all 0.3s;
}
.case-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
}
.case-tag {
  background: var(--primary);
  color: var(--accent-light);
  padding: 6px 16px;
  font-size: 13px;
  font-weight: 600;
}
.case-body { padding: 20px; }
.case-body h3 {
  font-size: 17px;
  font-weight: 700;
  color: var(--primary);
  margin-bottom: 8px;
}
.case-meta {
  font-size: 13px;
  color: var(--text-light);
  margin-bottom: 8px;
  line-height: 1.6;
}
.case-result {
  font-size: 14px;
  color: var(--success);
  font-weight: 600;
  margin-top: 10px;
  padding-top: 10px;
  border-top: 1px solid var(--border);
}

/* ===== 联系信息 ===== */
.contact-info-item {
  display: flex;
  gap: 16px;
  margin-bottom: 24px;
  align-items: flex-start;
}
.contact-info-icon {
  width: 48px;
  height: 48px;
  background: var(--bg-gray);
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--accent);
  flex-shrink: 0;
}
.contact-info-item h4 {
  font-size: 16px;
  font-weight: 700;
  color: var(--primary);
  margin-bottom: 4px;
}
.contact-info-item p {
  font-size: 15px;
  color: var(--text);
}

/* ===== 资质证书 ===== */
.cert-badge {
  background: var(--bg-gray);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 16px 20px;
  font-size: 13px;
  color: var(--text);
}
.cert-badge strong {
  color: var(--primary);
  display: block;
  margin-bottom: 4px;
  font-size: 14px;
}

/* ===== 时间线（发展历程） ===== */
.timeline {
  position: relative;
  padding-left: 40px;
}
.timeline::before {
  content: '';
  position: absolute;
  left: 12px;
  top: 0;
  bottom: 0;
  width: 2px;
  background: var(--border);
}
.timeline-item {
  position: relative;
  margin-bottom: 28px;
}
.timeline-item::before {
  content: '';
  position: absolute;
  left: -34px;
  top: 6px;
  width: 12px;
  height: 12px;
  background: var(--accent);
  border-radius: 50%;
  border: 2px solid white;
  box-shadow: 0 0 0 2px var(--accent);
}
.timeline-year {
  font-size: 18px;
  font-weight: 700;
  color: var(--primary);
  margin-bottom: 4px;
}
.timeline-desc {
  font-size: 15px;
  color: var(--text-light);
  line-height: 1.7;
}

/* ===== 响应式 ===== */
@media (max-width: 900px) {
  .nav-links { display: none; }
  .mobile-toggle { display: block; }
  .nav-links.open {
    display: flex;
    flex-direction: column;
    position: absolute;
    top: 64px;
    left: 0;
    right: 0;
    background: var(--primary);
    padding: 20px;
    gap: 16px;
  }
  .hero h1 { font-size: 28px; }
  .hero-stats { gap: 24px; }
  .card-grid-3, .card-grid-4 { grid-template-columns: 1fr; }
  .card-grid-2 { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr 1fr; }
  .section-title h2 { font-size: 24px; }
}
@media (max-width: 500px) {
  .footer-grid { grid-template-columns: 1fr; }
  .hero-stats { gap: 16px; }
  .stat-item h3 { font-size: 28px; }
}

/* ===== FAQ全展开式（搜索引擎友好） ===== */
.faq-full-list { max-width: 900px; margin: 0 auto; }
.faq-full-item { background: white; border: 1px solid var(--border); border-radius: var(--radius); padding: 24px 28px; margin-bottom: 16px; }
.faq-full-item h3 { font-size: 17px; font-weight: 700; color: var(--primary); margin-bottom: 12px; line-height: 1.5; }
.faq-full-item h3::before { content: "Q："; color: var(--accent); font-weight: 800; }
.faq-full-item .faq-answer { font-size: 15px; color: var(--text); line-height: 1.9; }
.faq-full-item .faq-answer p { margin-bottom: 8px; }
.faq-full-item .faq-answer ul, .faq-full-item .faq-answer ol { margin: 8px 0; padding-left: 24px; line-height: 1.9; }
.faq-full-item .faq-answer strong { color: var(--primary); }
.faq-category-title { font-size: 22px; font-weight: 800; color: var(--primary); margin: 40px 0 20px; padding-left: 12px; border-left: 4px solid var(--accent); }
.faq-category-title:first-child { margin-top: 0; }

/* Native disclosure remains operable when JavaScript is unavailable. */
.faq-question { list-style: none; }
.faq-question::-webkit-details-marker { display: none; }