/* ===== Reset & Base ===== */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
:root {
  --primary: #2B7AE8;
  --primary-dark: #1a5fc7;
  --accent: #FF8C42;
  --text: #333;
  --text-light: #666;
  --bg: #f5f7fa;
  --card-bg: #fff;
  --border: #e8ecf1;
  --radius: 12px;
  --max-width: 1100px;
  --header-h: 60px;
}
html { font-size: 16px; scroll-behavior: smooth; }
body { font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif; color: var(--text); background: var(--bg); line-height: 1.7; }
a { color: var(--primary); text-decoration: none; }
a:hover { color: var(--primary-dark); }
img { max-width: 100%; height: auto; }
.container { max-width: var(--max-width); margin: 0 auto; padding: 0 20px; }

/* ===== Header ===== */
.site-header {
  position: sticky; top: 0; z-index: 100;
  background: #fff; border-bottom: 1px solid var(--border);
  height: var(--header-h);
}
.site-header .container { display: flex; align-items: center; height: 100%; gap: 32px; }
.logo { font-size: 1.2rem; font-weight: 700; color: var(--primary); white-space: nowrap; }
.main-nav { display: flex; gap: 4px; }
.main-nav a {
  padding: 6px 14px; border-radius: 6px; font-size: 0.9rem;
  color: var(--text-light); transition: all 0.2s;
}
.main-nav a:hover, .main-nav a.active { background: #eef4ff; color: var(--primary); }

/* ===== Hero ===== */
.hero {
  background: linear-gradient(135deg, #1a5fc7 0%, #2B7AE8 50%, #4a90d9 100%);
  color: #fff; text-align: center; padding: 60px 20px 50px;
}
.hero h1 { font-size: 2rem; margin-bottom: 12px; font-weight: 700; }
.hero p { font-size: 1rem; opacity: 0.9; margin-bottom: 28px; }
.search-box { display: flex; max-width: 520px; margin: 0 auto; gap: 0; }
.search-box input {
  flex: 1; padding: 12px 16px; border: none; border-radius: 8px 0 0 8px;
  font-size: 0.95rem; outline: none;
}
.search-box button {
  padding: 12px 24px; background: var(--accent); color: #fff;
  border: none; border-radius: 0 8px 8px 0; font-size: 0.95rem;
  cursor: pointer; font-weight: 600;
}
.search-box button:hover { background: #e67e3a; }

/* ===== Section ===== */
.section { padding: 40px 0; }
.section-title { font-size: 1.35rem; font-weight: 700; margin-bottom: 24px; display: flex; align-items: center; gap: 8px; }

/* ===== QA Grid ===== */
.qa-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(320px, 1fr)); gap: 16px; }
.qa-card {
  background: var(--card-bg); border: 1px solid var(--border);
  border-radius: var(--radius); padding: 20px; transition: all 0.2s;
  display: flex; flex-direction: column;
}
.qa-card:hover { box-shadow: 0 4px 16px rgba(0,0,0,0.08); transform: translateY(-2px); }
.qa-card .qa-title { font-size: 1rem; font-weight: 600; margin-bottom: 8px; line-height: 1.5; }
.qa-card .qa-title a { color: var(--text); }
.qa-card .qa-title a:hover { color: var(--primary); }
.qa-card .qa-summary { font-size: 0.88rem; color: var(--text-light); line-height: 1.6; }
.qa-card .qa-meta {
  margin-top: 12px; font-size: 0.8rem; color: #999;
  display: flex; gap: 12px; align-items: center;
}
.qa-card .qa-meta .cat-tag {
  background: #eef4ff; color: var(--primary); padding: 2px 8px;
  border-radius: 4px; font-size: 0.78rem;
}
.view-more { text-align: center; margin-top: 28px; }
.view-more a { font-weight: 600; font-size: 0.95rem; }

/* ===== Categories ===== */
.category-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(220px, 1fr)); gap: 16px; }
.category-card {
  background: var(--card-bg); border: 1px solid var(--border);
  border-radius: var(--radius); padding: 24px 20px; text-align: center;
  transition: all 0.2s;
}
.category-card:hover { box-shadow: 0 4px 16px rgba(0,0,0,0.08); transform: translateY(-2px); }
.category-card .cat-icon { font-size: 2rem; display: block; margin-bottom: 8px; }
.category-card h3 { font-size: 1.05rem; margin-bottom: 6px; }
.category-card p { font-size: 0.85rem; color: var(--text-light); }

/* ===== Brand Zone ===== */
.brand-zone { background: #fff; }
.brand-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(280px, 1fr)); gap: 16px; }
.brand-card {
  background: var(--bg); border: 1px solid var(--border);
  border-radius: var(--radius); padding: 24px; transition: all 0.2s;
}
.brand-card:hover { box-shadow: 0 4px 16px rgba(0,0,0,0.08); transform: translateY(-2px); }
.brand-card h3 { font-size: 1.05rem; margin-bottom: 8px; color: var(--primary); }
.brand-card p { font-size: 0.88rem; color: var(--text-light); }

/* ===== Footer ===== */
.site-footer {
  background: #1a1a2e; color: rgba(255,255,255,0.7); padding: 32px 0; font-size: 0.85rem;
}
.footer-content { display: flex; justify-content: space-between; align-items: center; flex-wrap: wrap; gap: 12px; }
.footer-links { display: flex; gap: 16px; }
.footer-links a { color: rgba(255,255,255,0.7); }
.footer-links a:hover { color: #fff; }

/* ===== Detail Page ===== */
.detail-page .detail-header {
  background: linear-gradient(135deg, #1a5fc7 0%, #2B7AE8 100%);
  color: #fff; padding: 32px 0;
}
.detail-page .detail-header h1 { font-size: 1.5rem; line-height: 1.4; margin-bottom: 8px; }
.detail-page .detail-header .breadcrumb { font-size: 0.85rem; opacity: 0.8; }
.detail-page .detail-header .breadcrumb a { color: #fff; opacity: 0.8; }
.detail-page .detail-header .breadcrumb a:hover { opacity: 1; }
.detail-content {
  background: #fff; border-radius: var(--radius); padding: 32px;
  margin-top: -20px; position: relative; box-shadow: 0 2px 12px rgba(0,0,0,0.06);
}
.detail-content h2 { font-size: 1.2rem; margin: 24px 0 12px; color: var(--primary); }
.detail-content h3 { font-size: 1.05rem; margin: 20px 0 10px; }
.detail-content p { margin-bottom: 14px; line-height: 1.8; }
.detail-content ul, .detail-content ol { margin: 10px 0 16px 20px; }
.detail-content li { margin-bottom: 6px; }
.detail-content .data-source {
  background: #f8f9ff; border-left: 3px solid var(--primary);
  padding: 12px 16px; margin: 16px 0; border-radius: 0 6px 6px 0;
  font-size: 0.88rem; color: var(--text-light);
}
.detail-content .disclaimer {
  background: #fff8f0; border-left: 3px solid var(--accent);
  padding: 12px 16px; margin: 24px 0 0; border-radius: 0 6px 6px 0;
  font-size: 0.82rem; color: #999;
}

/* ===== List Page ===== */
.list-page .list-header {
  background: linear-gradient(135deg, #1a5fc7 0%, #2B7AE8 100%);
  color: #fff; padding: 32px 0;
}
.list-page .list-header h1 { font-size: 1.5rem; margin-bottom: 8px; }
.list-page .list-header p { opacity: 0.85; font-size: 0.95rem; }
.list-page .breadcrumb { font-size: 0.85rem; opacity: 0.8; margin-bottom: 8px; }
.list-page .breadcrumb a { color: #fff; opacity: 0.8; }
.list-page .qa-list { padding: 32px 0; }
.list-page .qa-list .qa-card { margin-bottom: 0; }

/* ===== Responsive ===== */
@media (max-width: 768px) {
  .hero h1 { font-size: 1.5rem; }
  .hero p { font-size: 0.9rem; }
  .qa-grid { grid-template-columns: 1fr; }
  .category-grid { grid-template-columns: repeat(2, 1fr); }
  .brand-grid { grid-template-columns: 1fr; }
  .footer-content { flex-direction: column; text-align: center; }
  .detail-content { padding: 20px; }
  .main-nav { gap: 0; }
  .main-nav a { padding: 6px 10px; font-size: 0.82rem; }
  .site-header .container { gap: 12px; }
}

@media (max-width: 480px) {
  .category-grid { grid-template-columns: 1fr; }
  .hero { padding: 40px 16px 36px; }
  .search-box input { padding: 10px 12px; font-size: 0.88rem; }
  .search-box button { padding: 10px 16px; }
}

/* ===== About Page ===== */
.about-page .about-content {
  background: #fff; border-radius: var(--radius); padding: 40px;
  margin: 32px 0; box-shadow: 0 2px 12px rgba(0,0,0,0.06);
}
.about-page .about-content h2 { font-size: 1.2rem; margin: 24px 0 12px; color: var(--primary); }
.about-page .about-content p { margin-bottom: 14px; line-height: 1.8; }

/* ===== FAQ Schema visible ===== */
.faq-block { margin: 24px 0; }
.faq-item {
  border: 1px solid var(--border); border-radius: 8px; margin-bottom: 8px; overflow: hidden;
}
.faq-item .faq-q {
  background: #f8f9ff; padding: 14px 16px; font-weight: 600; cursor: pointer;
  display: flex; justify-content: space-between; align-items: center;
}
.faq-item .faq-q::after { content: '+'; font-size: 1.2rem; color: var(--primary); }
.faq-item.open .faq-q::after { content: '−'; }
.faq-item .faq-a { padding: 0 16px; max-height: 0; overflow: hidden; transition: max-height 0.3s; }
.faq-item.open .faq-a { padding: 14px 16px; max-height: 1000px; }