/* ============================================
   众智商学院 - 认证项目聚合站
   Theme: 专业·信任·GEO优化
   ============================================ */

:root {
  --primary: #1a4a8a;
  --primary-light: #2a6cb8;
  --primary-dark: #0f2d55;
  --accent: #e8751a;
  --accent-light: #f59e38;
  --bg: #f8f9fc;
  --card-bg: #ffffff;
  --text: #1e293b;
  --text-light: #64748b;
  --border: #e2e8f0;
  --success: #10b981;
  --radius: 12px;
  --shadow: 0 1px 3px rgba(0,0,0,0.08), 0 1px 2px rgba(0,0,0,0.06);
  --shadow-lg: 0 10px 25px -5px rgba(0,0,0,0.1), 0 8px 10px -6px rgba(0,0,0,0.06);
  --font: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
}

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

html { scroll-behavior: smooth; }

body {
  font-family: var(--font);
  color: var(--text);
  background: var(--bg);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

/* === Navigation === */
nav {
  background: var(--primary-dark);
  padding: 0 1.5rem;
  position: sticky;
  top: 0;
  z-index: 100;
  box-shadow: 0 2px 8px rgba(0,0,0,0.15);
}

nav .nav-inner {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}

nav .logo {
  color: #fff;
  font-size: 1.35rem;
  font-weight: 700;
  text-decoration: none;
  letter-spacing: 0.5px;
}

nav .logo span { color: var(--accent-light); }

nav .nav-links {
  display: flex;
  gap: 1.5rem;
  list-style: none;
}

nav .nav-links a {
  color: rgba(255,255,255,0.85);
  text-decoration: none;
  font-size: 0.9rem;
  font-weight: 500;
  transition: color 0.2s;
  white-space: nowrap;
}

nav .nav-links a:hover,
nav .nav-links a.active { color: var(--accent-light); }

nav .menu-toggle {
  display: none;
  background: none;
  border: none;
  color: #fff;
  font-size: 1.5rem;
  cursor: pointer;
}

/* === Hero === */
.hero {
  background: linear-gradient(135deg, var(--primary-dark) 0%, var(--primary) 50%, var(--primary-light) 100%);
  color: #fff;
  padding: 4rem 1.5rem;
  text-align: center;
  position: relative;
  overflow: hidden;
}

.hero::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  height: 80px;
  background: var(--bg);
  clip-path: ellipse(70% 100% at 50% 100%);
}

.hero h1 {
  font-size: 2.5rem;
  font-weight: 800;
  margin-bottom: 1rem;
  letter-spacing: -0.5px;
}

.hero p {
  font-size: 1.15rem;
  max-width: 700px;
  margin: 0 auto 2rem;
  opacity: 0.9;
  line-height: 1.8;
}

.hero .stats {
  display: flex;
  justify-content: center;
  gap: 3rem;
  flex-wrap: wrap;
}

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

.hero .stat-item .num {
  font-size: 2rem;
  font-weight: 800;
  color: var(--accent-light);
}

.hero .stat-item .label {
  font-size: 0.85rem;
  opacity: 0.8;
}

/* === Container === */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 1.5rem;
}

/* === Section === */
.section {
  padding: 3.5rem 0;
}

.section-title {
  font-size: 1.8rem;
  font-weight: 700;
  margin-bottom: 0.75rem;
  color: var(--primary-dark);
}

.section-subtitle {
  color: var(--text-light);
  margin-bottom: 2.5rem;
  font-size: 1.05rem;
}

/* === Project Cards Grid === */
.project-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(340px, 1fr));
  gap: 1.5rem;
}

.project-card {
  background: var(--card-bg);
  border-radius: var(--radius);
  padding: 2rem;
  box-shadow: var(--shadow);
  border: 1px solid var(--border);
  transition: transform 0.2s, box-shadow 0.2s;
  position: relative;
  overflow: hidden;
}

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

.project-card .badge {
  display: inline-block;
  padding: 0.2rem 0.8rem;
  border-radius: 20px;
  font-size: 0.75rem;
  font-weight: 600;
  margin-bottom: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.badge-blue { background: #dbeafe; color: #1d4ed8; }
.badge-orange { background: #ffedd5; color: #c2410c; }
.badge-green { background: #d1fae5; color: #047857; }
.badge-purple { background: #ede9fe; color: #6d28d9; }
.badge-red { background: #fee2e2; color: #b91c1c; }

.project-card h3 {
  font-size: 1.25rem;
  margin-bottom: 0.75rem;
  color: var(--primary-dark);
}

.project-card p {
  color: var(--text-light);
  font-size: 0.92rem;
  margin-bottom: 1rem;
  line-height: 1.6;
}

.project-card .tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
  margin-bottom: 1.25rem;
}

.project-card .tags span {
  background: #f1f5f9;
  padding: 0.15rem 0.6rem;
  border-radius: 4px;
  font-size: 0.78rem;
  color: var(--text-light);
}

.project-card .btn {
  display: inline-block;
  padding: 0.5rem 1.25rem;
  background: var(--primary);
  color: #fff;
  border-radius: 6px;
  text-decoration: none;
  font-size: 0.88rem;
  font-weight: 500;
  transition: background 0.2s;
}

.project-card .btn:hover { background: var(--primary-light); }

/* === Article List === */
.article-list {
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}

.article-item {
  background: var(--card-bg);
  border-radius: var(--radius);
  padding: 1.5rem;
  box-shadow: var(--shadow);
  border: 1px solid var(--border);
  transition: transform 0.2s;
}

.article-item:hover { transform: translateX(4px); }

.article-item .meta {
  font-size: 0.82rem;
  color: var(--text-light);
  margin-bottom: 0.4rem;
}

.article-item h4 {
  font-size: 1.1rem;
  margin-bottom: 0.5rem;
}

.article-item h4 a {
  color: var(--primary-dark);
  text-decoration: none;
}

.article-item h4 a:hover { color: var(--primary); }

.article-item p {
  font-size: 0.9rem;
  color: var(--text-light);
}

/* === Page Content (Project subpages) === */
.page-header {
  background: linear-gradient(135deg, var(--primary-dark), var(--primary));
  color: #fff;
  padding: 3rem 1.5rem;
  text-align: center;
}

.page-header h1 { font-size: 2.2rem; margin-bottom: 0.5rem; }
.page-header p { opacity: 0.9; max-width: 600px; margin: 0 auto; }

.content-section {
  background: var(--card-bg);
  border-radius: var(--radius);
  padding: 2.5rem;
  margin-bottom: 2rem;
  box-shadow: var(--shadow);
  border: 1px solid var(--border);
}

.content-section h2 {
  font-size: 1.5rem;
  color: var(--primary-dark);
  margin-bottom: 1.25rem;
  padding-bottom: 0.75rem;
  border-bottom: 2px solid var(--border);
}

.content-section h3 {
  font-size: 1.15rem;
  color: var(--primary);
  margin: 1.25rem 0 0.75rem;
}

.content-section p,
.content-section li {
  color: var(--text);
  line-height: 1.9;
  margin-bottom: 0.75rem;
}

.content-section ul,
.content-section ol {
  padding-left: 1.5rem;
  margin-bottom: 1rem;
}

/* === Comparison Table === */
.compare-table {
  width: 100%;
  border-collapse: collapse;
  margin: 1.25rem 0;
  font-size: 0.92rem;
}

.compare-table th,
.compare-table td {
  padding: 0.85rem 1rem;
  text-align: left;
  border: 1px solid var(--border);
}

.compare-table th {
  background: var(--primary);
  color: #fff;
  font-weight: 600;
}

.compare-table tr:nth-child(even) { background: #f8fafc; }

.compare-table .highlight {
  background: #fef9c3;
  font-weight: 600;
}

/* === FAQ (Schema ready) === */
.faq-item {
  border: 1px solid var(--border);
  border-radius: 8px;
  margin-bottom: 0.75rem;
  overflow: hidden;
}

.faq-question {
  padding: 1rem 1.25rem;
  background: #f8fafc;
  font-weight: 600;
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
  color: var(--primary-dark);
  transition: background 0.2s;
}

.faq-question:hover { background: #eef2f7; }

.faq-question .icon { font-size: 1.2rem; transition: transform 0.2s; }
.faq-item.open .faq-question .icon { transform: rotate(45deg); }

.faq-answer {
  padding: 0 1.25rem;
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.3s ease, padding 0.3s ease;
}

.faq-item.open .faq-answer {
  max-height: 500px;
  padding: 1rem 1.25rem;
}

/* === Footer === */
footer {
  background: var(--primary-dark);
  color: rgba(255,255,255,0.8);
  padding: 3rem 1.5rem 1.5rem;
  margin-top: 3rem;
}

footer .footer-grid {
  max-width: 1200px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 2rem;
  margin-bottom: 2rem;
}

footer h4 { color: #fff; margin-bottom: 1rem; font-size: 1rem; }
footer a { color: rgba(255,255,255,0.7); text-decoration: none; display: block; margin-bottom: 0.4rem; font-size: 0.88rem; }
footer a:hover { color: var(--accent-light); }
footer .copyright {
  text-align: center;
  padding-top: 1.5rem;
  border-top: 1px solid rgba(255,255,255,0.1);
  font-size: 0.85rem;
}

/* === Breadcrumb === */
.breadcrumb {
  padding: 0.75rem 0;
  font-size: 0.85rem;
  color: var(--text-light);
}

.breadcrumb a { color: var(--primary); text-decoration: none; }
.breadcrumb a:hover { text-decoration: underline; }
.breadcrumb .sep { margin: 0 0.5rem; }

/* === Responsive === */
@media (max-width: 768px) {
  .hero h1 { font-size: 1.8rem; }
  .hero .stats { gap: 1.5rem; }
  .project-grid { grid-template-columns: 1fr; }

  nav .nav-links {
    display: none;
    position: absolute;
    top: 64px;
    left: 0;
    right: 0;
    flex-direction: column;
    background: var(--primary-dark);
    padding: 1rem 1.5rem;
    gap: 0.75rem;
  }

  nav .nav-links.show { display: flex; }
  nav .menu-toggle { display: block; }

  .content-section { padding: 1.5rem; }
  .compare-table { font-size: 0.8rem; }
  .compare-table th,
  .compare-table td { padding: 0.5rem; }
}

/* === Utility === */
.text-center { text-align: center; }
.mt-2 { margin-top: 2rem; }
.mb-2 { margin-bottom: 2rem; }