/* GEO研究博客 - 主样式文件 */
/* 设计风格：现代科技感，蓝色系，专业可信赖 */

/* ===== CSS Variables ===== */
:root {
  --primary: #2563eb;
  --primary-dark: #1d4ed8;
  --primary-light: #3b82f6;
  --primary-bg: #eff6ff;
  --secondary: #7c3aed;
  --success: #059669;
  --warning: #dc2626;
  --text-primary: #1e293b;
  --text-secondary: #475569;
  --text-muted: #94a3b8;
  --bg-primary: #ffffff;
  --bg-secondary: #f8fafc;
  --bg-tertiary: #f1f5f9;
  --border: #e2e8f0;
  --border-dark: #cbd5e1;
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow: 0 1px 3px 0 rgba(0, 0, 0, 0.1), 0 1px 2px -1px rgba(0, 0, 0, 0.1);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -2px rgba(0, 0, 0, 0.1);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -4px rgba(0, 0, 0, 0.1);
  --radius: 8px;
  --radius-lg: 12px;
  --transition: all 0.2s ease;
  --font-sans: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', sans-serif;
  --font-mono: 'SF Mono', 'Fira Code', 'Fira Mono', 'Roboto Mono', monospace;
}

/* ===== Reset & Base ===== */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  font-size: 16px;
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-sans);
  color: var(--text-primary);
  background: var(--bg-secondary);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

a {
  color: var(--primary);
  text-decoration: none;
  transition: var(--transition);
}

a:hover {
  color: var(--primary-dark);
}

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

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

.container-narrow {
  max-width: 800px;
  margin: 0 auto;
  padding: 0 1.5rem;
}

/* ===== Header ===== */
.header {
  background: var(--bg-primary);
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  z-index: 100;
  box-shadow: var(--shadow-sm);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--text-primary);
}

.logo-icon {
  width: 32px;
  height: 32px;
  background: linear-gradient(135deg, var(--primary), var(--secondary));
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-size: 1rem;
}

.nav {
  display: flex;
  align-items: center;
  gap: 2rem;
}

.nav-link {
  color: var(--text-secondary);
  font-size: 0.9375rem;
  font-weight: 500;
  padding: 0.5rem 0;
  position: relative;
}

.nav-link:hover,
.nav-link.active {
  color: var(--primary);
}

.nav-link.active::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 0;
  right: 0;
  height: 2px;
  background: var(--primary);
  border-radius: 1px;
}

.mobile-menu-btn {
  display: none;
  background: none;
  border: none;
  padding: 0.5rem;
  cursor: pointer;
  color: var(--text-primary);
}

/* ===== Hero Section ===== */
.hero {
  background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
  color: white;
  padding: 5rem 0;
  text-align: center;
}

.hero-title {
  font-size: 2.5rem;
  font-weight: 800;
  margin-bottom: 1rem;
  line-height: 1.2;
}

.hero-subtitle {
  font-size: 1.25rem;
  opacity: 0.9;
  margin-bottom: 2rem;
  max-width: 600px;
  margin-left: auto;
  margin-right: auto;
}

.hero-actions {
  display: flex;
  gap: 1rem;
  justify-content: center;
  flex-wrap: wrap;
}

/* ===== Buttons ===== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.75rem 1.5rem;
  border-radius: var(--radius);
  font-size: 0.9375rem;
  font-weight: 600;
  cursor: pointer;
  transition: var(--transition);
  border: none;
  text-decoration: none;
}

.btn-primary {
  background: var(--primary);
  color: white;
}

.btn-primary:hover {
  background: var(--primary-dark);
  color: white;
  transform: translateY(-1px);
  box-shadow: var(--shadow-md);
}

.btn-outline {
  background: transparent;
  color: white;
  border: 2px solid rgba(255, 255, 255, 0.5);
}

.btn-outline:hover {
  background: rgba(255, 255, 255, 0.1);
  border-color: white;
  color: white;
}

.btn-secondary {
  background: var(--bg-tertiary);
  color: var(--text-primary);
}

.btn-secondary:hover {
  background: var(--border);
}

.btn-sm {
  padding: 0.5rem 1rem;
  font-size: 0.875rem;
}

/* ===== Section ===== */
.section {
  padding: 4rem 0;
}

.section-header {
  text-align: center;
  margin-bottom: 3rem;
}

.section-title {
  font-size: 1.875rem;
  font-weight: 700;
  margin-bottom: 0.5rem;
}

.section-subtitle {
  color: var(--text-secondary);
  font-size: 1.0625rem;
}

/* ===== Cards ===== */
.card {
  background: var(--bg-primary);
  border-radius: var(--radius-lg);
  border: 1px solid var(--border);
  overflow: hidden;
  transition: var(--transition);
}

.card:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
}

.card-body {
  padding: 1.5rem;
}

.card-title {
  font-size: 1.25rem;
  font-weight: 600;
  margin-bottom: 0.5rem;
  line-height: 1.4;
}

.card-title a {
  color: var(--text-primary);
}

.card-title a:hover {
  color: var(--primary);
}

.card-meta {
  display: flex;
  align-items: center;
  gap: 1rem;
  color: var(--text-muted);
  font-size: 0.875rem;
  margin-bottom: 0.75rem;
}

.card-excerpt {
  color: var(--text-secondary);
  font-size: 0.9375rem;
  line-height: 1.6;
  margin-bottom: 1rem;
}

.card-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: 1rem;
  border-top: 1px solid var(--border);
}

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

/* ===== Category Badge ===== */
.category-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.25rem;
  padding: 0.25rem 0.75rem;
  border-radius: 9999px;
  font-size: 0.75rem;
  font-weight: 600;
}

.category-badge.geo { background: #eff6ff; color: #2563eb; }
.category-badge.ai { background: #f5f3ff; color: #7c3aed; }
.category-badge.case { background: #ecfdf5; color: #059669; }
.category-badge.trends { background: #fef2f2; color: #dc2626; }

/* ===== Tags ===== */
.tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.tag {
  display: inline-block;
  padding: 0.25rem 0.625rem;
  background: var(--bg-tertiary);
  color: var(--text-secondary);
  border-radius: 4px;
  font-size: 0.75rem;
  font-weight: 500;
}

/* ===== Filter Bar ===== */
.filter-bar {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  margin-bottom: 2rem;
  flex-wrap: wrap;
}

.filter-btn {
  padding: 0.5rem 1rem;
  border-radius: var(--radius);
  font-size: 0.875rem;
  font-weight: 500;
  cursor: pointer;
  transition: var(--transition);
  border: 1px solid var(--border);
  background: var(--bg-primary);
  color: var(--text-secondary);
}

.filter-btn:hover {
  border-color: var(--primary);
  color: var(--primary);
}

.filter-btn.active {
  background: var(--primary);
  border-color: var(--primary);
  color: white;
}

/* ===== Article Content ===== */
.article {
  background: var(--bg-primary);
  border-radius: var(--radius-lg);
  border: 1px solid var(--border);
  padding: 2.5rem;
  margin-bottom: 2rem;
}

.article-header {
  margin-bottom: 2rem;
  padding-bottom: 2rem;
  border-bottom: 1px solid var(--border);
}

.article-title {
  font-size: 2rem;
  font-weight: 800;
  line-height: 1.3;
  margin-bottom: 1rem;
}

.article-meta {
  display: flex;
  align-items: center;
  gap: 1.5rem;
  color: var(--text-muted);
  font-size: 0.9375rem;
}

.article-content {
  font-size: 1.0625rem;
  line-height: 1.8;
  color: var(--text-primary);
}

.article-content h2 {
  font-size: 1.5rem;
  font-weight: 700;
  margin: 2rem 0 1rem;
  padding-bottom: 0.5rem;
  border-bottom: 2px solid var(--primary-bg);
}

.article-content h3 {
  font-size: 1.25rem;
  font-weight: 600;
  margin: 1.5rem 0 0.75rem;
}

.article-content p {
  margin-bottom: 1.25rem;
}

.article-content ul,
.article-content ol {
  margin: 1rem 0 1.25rem 1.5rem;
}

.article-content li {
  margin-bottom: 0.5rem;
}

.article-content table {
  width: 100%;
  border-collapse: collapse;
  margin: 1.5rem 0;
  font-size: 0.9375rem;
}

.article-content th,
.article-content td {
  padding: 0.75rem 1rem;
  border: 1px solid var(--border);
  text-align: left;
}

.article-content th {
  background: var(--bg-tertiary);
  font-weight: 600;
}

.article-content pre {
  background: var(--bg-tertiary);
  border-radius: var(--radius);
  padding: 1.25rem;
  overflow-x: auto;
  margin: 1.5rem 0;
}

.article-content code {
  font-family: var(--font-mono);
  font-size: 0.875rem;
}

.article-content p code {
  background: var(--bg-tertiary);
  padding: 0.125rem 0.375rem;
  border-radius: 4px;
}

/* ===== Author Box ===== */
.author-box {
  display: flex;
  align-items: center;
  gap: 1.5rem;
  padding: 1.5rem;
  background: var(--bg-tertiary);
  border-radius: var(--radius-lg);
  margin-top: 2rem;
}

.author-avatar {
  width: 64px;
  height: 64px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--primary), var(--secondary));
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-size: 1.5rem;
  font-weight: 700;
  flex-shrink: 0;
}

.author-info h4 {
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: 0.25rem;
}

.author-info p {
  color: var(--text-secondary);
  font-size: 0.875rem;
  margin-bottom: 0.5rem;
}

.author-contact {
  display: flex;
  gap: 1rem;
  font-size: 0.8125rem;
  color: var(--text-muted);
}

/* ===== Skills Grid ===== */
.skills-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 1.5rem;
}

.skill-card {
  background: var(--bg-primary);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 1.5rem;
  text-align: center;
  transition: var(--transition);
}

.skill-card:hover {
  border-color: var(--primary);
  box-shadow: var(--shadow-md);
}

.skill-icon {
  width: 56px;
  height: 56px;
  margin: 0 auto 1rem;
  background: var(--primary-bg);
  border-radius: var(--radius-lg);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
}

.skill-title {
  font-size: 1.0625rem;
  font-weight: 600;
  margin-bottom: 0.5rem;
}

.skill-desc {
  color: var(--text-secondary);
  font-size: 0.875rem;
}

/* ===== Cases Grid ===== */
.cases-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 1.5rem;
}

.case-card {
  background: var(--bg-primary);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 2rem;
  transition: var(--transition);
}

.case-card:hover {
  border-color: var(--primary);
  box-shadow: var(--shadow-md);
}

.case-header {
  display: flex;
  align-items: center;
  gap: 1rem;
  margin-bottom: 1rem;
}

.case-icon {
  width: 48px;
  height: 48px;
  background: var(--primary-bg);
  border-radius: var(--radius);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.25rem;
}

.case-title {
  font-size: 1.125rem;
  font-weight: 600;
}

.case-desc {
  color: var(--text-secondary);
  font-size: 0.9375rem;
  margin-bottom: 1rem;
  line-height: 1.6;
}

.case-results {
  display: flex;
  gap: 1.5rem;
  padding-top: 1rem;
  border-top: 1px solid var(--border);
}

.case-result {
  text-align: center;
}

.case-result-value {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--primary);
}

.case-result-label {
  font-size: 0.75rem;
  color: var(--text-muted);
}

/* ===== Resources Grid ===== */
.resources-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 1.5rem;
}

.resource-card {
  background: var(--bg-primary);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 1.5rem;
  transition: var(--transition);
}

.resource-card:hover {
  border-color: var(--primary);
  box-shadow: var(--shadow-md);
}

.resource-type {
  display: inline-block;
  padding: 0.25rem 0.5rem;
  background: var(--primary-bg);
  color: var(--primary);
  border-radius: 4px;
  font-size: 0.75rem;
  font-weight: 600;
  margin-bottom: 0.75rem;
}

.resource-title {
  font-size: 1.0625rem;
  font-weight: 600;
  margin-bottom: 0.5rem;
}

.resource-desc {
  color: var(--text-secondary);
  font-size: 0.875rem;
  line-height: 1.5;
  margin-bottom: 1rem;
}

.resource-link {
  font-size: 0.875rem;
  font-weight: 500;
}

/* ===== About Page ===== */
.about-hero {
  text-align: center;
  padding: 4rem 0 3rem;
}

.about-avatar {
  width: 120px;
  height: 120px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--primary), var(--secondary));
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-size: 3rem;
  font-weight: 700;
  margin: 0 auto 1.5rem;
}

.about-name {
  font-size: 1.875rem;
  font-weight: 700;
  margin-bottom: 0.5rem;
}

.about-title {
  color: var(--text-secondary);
  font-size: 1.125rem;
  margin-bottom: 1rem;
}

.about-bio {
  max-width: 600px;
  margin: 0 auto;
  color: var(--text-secondary);
  line-height: 1.8;
}

.about-section {
  background: var(--bg-primary);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 2rem;
  margin-bottom: 1.5rem;
}

.about-section-title {
  font-size: 1.25rem;
  font-weight: 600;
  margin-bottom: 1rem;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.contact-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 1rem;
}

.contact-item {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  padding: 1rem;
  background: var(--bg-tertiary);
  border-radius: var(--radius);
}

.contact-icon {
  width: 40px;
  height: 40px;
  background: var(--primary-bg);
  border-radius: var(--radius);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--primary);
  font-size: 1.125rem;
}

.contact-label {
  font-size: 0.75rem;
  color: var(--text-muted);
}

.contact-value {
  font-weight: 500;
  font-size: 0.9375rem;
}

/* ===== Footer ===== */
.footer {
  background: var(--bg-primary);
  border-top: 1px solid var(--border);
  padding: 3rem 0 2rem;
  margin-top: 4rem;
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 2rem;
  margin-bottom: 2rem;
}

.footer-brand {
  max-width: 300px;
}

.footer-brand-name {
  font-size: 1.125rem;
  font-weight: 700;
  margin-bottom: 0.5rem;
}

.footer-brand-desc {
  color: var(--text-secondary);
  font-size: 0.875rem;
  line-height: 1.6;
}

.footer-col-title {
  font-size: 0.875rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: 1rem;
}

.footer-links {
  list-style: none;
}

.footer-links li {
  margin-bottom: 0.5rem;
}

.footer-links a {
  color: var(--text-secondary);
  font-size: 0.875rem;
}

.footer-links a:hover {
  color: var(--primary);
}

.footer-bottom {
  padding-top: 1.5rem;
  border-top: 1px solid var(--border);
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 1rem;
}

.footer-copyright {
  color: var(--text-muted);
  font-size: 0.8125rem;
}

.footer-icp {
  color: var(--text-muted);
  font-size: 0.8125rem;
}

.footer-icp a {
  color: var(--text-muted);
}

.footer-icp a:hover {
  color: var(--primary);
}

/* ===== Pagination ===== */
.pagination {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 0.5rem;
  margin-top: 2rem;
}

.pagination-btn {
  padding: 0.5rem 0.75rem;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--bg-primary);
  color: var(--text-secondary);
  font-size: 0.875rem;
  cursor: pointer;
  transition: var(--transition);
}

.pagination-btn:hover {
  border-color: var(--primary);
  color: var(--primary);
}

.pagination-btn.active {
  background: var(--primary);
  border-color: var(--primary);
  color: white;
}

.pagination-btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

/* ===== Related Posts ===== */
.related-posts {
  margin-top: 3rem;
  padding-top: 2rem;
  border-top: 1px solid var(--border);
}

.related-posts-title {
  font-size: 1.25rem;
  font-weight: 600;
  margin-bottom: 1.5rem;
}

.related-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 1rem;
}

.related-card {
  padding: 1rem;
  background: var(--bg-tertiary);
  border-radius: var(--radius);
  transition: var(--transition);
}

.related-card:hover {
  background: var(--primary-bg);
}

.related-card-title {
  font-size: 0.9375rem;
  font-weight: 500;
  line-height: 1.4;
}

.related-card-title a {
  color: var(--text-primary);
}

.related-card-title a:hover {
  color: var(--primary);
}

/* ===== Responsive ===== */
@media (max-width: 1024px) {
  .footer-grid {
    grid-template-columns: 1fr 1fr;
  }
}

@media (max-width: 768px) {
  .hero {
    padding: 3rem 0;
  }

  .hero-title {
    font-size: 1.875rem;
  }

  .hero-subtitle {
    font-size: 1rem;
  }

  .section {
    padding: 2.5rem 0;
  }

  .section-title {
    font-size: 1.5rem;
  }

  .post-grid {
    grid-template-columns: 1fr;
  }

  .article {
    padding: 1.5rem;
  }

  .article-title {
    font-size: 1.5rem;
  }

  .article-meta {
    flex-wrap: wrap;
    gap: 0.75rem;
  }

  .author-box {
    flex-direction: column;
    text-align: center;
  }

  .footer-grid {
    grid-template-columns: 1fr;
  }

  .footer-bottom {
    flex-direction: column;
    text-align: center;
  }

  .nav {
    display: none;
    position: absolute;
    top: 64px;
    left: 0;
    right: 0;
    background: var(--bg-primary);
    border-bottom: 1px solid var(--border);
    flex-direction: column;
    padding: 1rem;
    gap: 0;
  }

  .nav.open {
    display: flex;
  }

  .nav-link {
    padding: 0.75rem 0;
    border-bottom: 1px solid var(--border);
  }

  .nav-link:last-child {
    border-bottom: none;
  }

  .mobile-menu-btn {
    display: block;
  }

  .filter-bar {
    overflow-x: auto;
    flex-wrap: nowrap;
    padding-bottom: 0.5rem;
  }

  .filter-btn {
    white-space: nowrap;
  }

  .cases-grid {
    grid-template-columns: 1fr;
  }

  .case-results {
    flex-wrap: wrap;
  }
}

@media (max-width: 480px) {
  .container {
    padding: 0 1rem;
  }

  .hero-title {
    font-size: 1.5rem;
  }

  .hero-actions {
    flex-direction: column;
    align-items: center;
  }

  .btn {
    width: 100%;
    max-width: 280px;
  }

  .skills-grid {
    grid-template-columns: 1fr;
  }

  .contact-grid {
    grid-template-columns: 1fr;
  }
}

/* ===== Utilities ===== */
.text-center { text-align: center; }
.text-muted { color: var(--text-muted); }
.mb-0 { margin-bottom: 0; }
.mb-1 { margin-bottom: 0.5rem; }
.mb-2 { margin-bottom: 1rem; }
.mb-3 { margin-bottom: 1.5rem; }
.mb-4 { margin-bottom: 2rem; }
.mt-2 { margin-top: 1rem; }
.mt-3 { margin-top: 1.5rem; }
.mt-4 { margin-top: 2rem; }