/* Reset and Base Styles */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  line-height: 1.6;
  color: #333;
  background-color: #fff;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
}

/* Header */
.header {
  border-bottom: 1px solid #e6e6e6;
  background-color: #fff;
  position: sticky;
  top: 0;
  z-index: 100;
}

.nav {
  padding: 1rem 0;
}

.nav-container {
  display: flex;
  justify-content: space-between;
  align-items: center;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
}

.logo {
  font-size: 1.5rem;
  font-weight: 700;
  color: #000;
  text-decoration: none;
  transition: color 0.3s ease;
}

.logo:hover {
  color: #666;
}

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

.nav-link {
  color: #666;
  text-decoration: none;
  font-weight: 400;
  transition: color 0.3s ease;
}

.nav-link:hover {
  color: #000;
}

/* Buttons */
.btn-primary {
  background-color: #000;
  color: #fff;
  border: none;
  padding: 0.75rem 1.5rem;
  border-radius: 50px;
  font-size: 0.875rem;
  font-weight: 500;
  cursor: pointer;
  transition: background-color 0.3s ease;
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
}

.btn-primary:hover {
  background-color: #333;
}

.btn-secondary {
  background-color: transparent;
  color: #000;
  border: 1px solid #e6e6e6;
  padding: 0.75rem 1.5rem;
  border-radius: 50px;
  font-size: 0.875rem;
  font-weight: 500;
  cursor: pointer;
  transition: all 0.3s ease;
  text-decoration: none;
}

.btn-secondary:hover {
  background-color: #f5f5f5;
  border-color: #ccc;
}

/* Hero Section */
.hero {
  padding: 4rem 0;
  text-align: center;
  background-color: #fafafa;
}

.hero-content {
  max-width: 600px;
  margin: 0 auto;
}

.hero-title {
  font-size: 3rem;
  font-weight: 700;
  margin-bottom: 1rem;
  color: #000;
  line-height: 1.2;
}

.hero-subtitle {
  font-size: 1.25rem;
  color: #666;
  margin-bottom: 2rem;
  font-weight: 400;
}

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

.social-link {
  color: #666;
  font-size: 1.5rem;
  transition: color 0.3s ease;
  text-decoration: none;
}

.social-link:hover {
  color: #000;
}

/* Articles Section */
.articles {
  padding: 4rem 0;
}

.articles-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 3rem;
}

.articles-header h2 {
  font-size: 2rem;
  font-weight: 700;
  color: #000;
}

.articles-filter {
  display: flex;
  gap: 1rem;
}

.filter-btn {
  background: none;
  border: none;
  color: #666;
  font-size: 0.875rem;
  font-weight: 500;
  cursor: pointer;
  padding: 0.5rem 1rem;
  border-radius: 20px;
  transition: all 0.3s ease;
}

.filter-btn.active,
.filter-btn:hover {
  background-color: #000;
  color: #fff;
}

.articles-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(350px, 1fr));
  gap: 2rem;
  margin-bottom: 3rem;
}

.article-card {
  border: 1px solid #e6e6e6;
  border-radius: 8px;
  padding: 1.5rem;
  background-color: #fff;
  transition: box-shadow 0.3s ease;
  cursor: pointer;
}

.article-card:hover {
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
}

.article-meta {
  display: flex;
  align-items: center;
  gap: 1rem;
  margin-bottom: 1rem;
  font-size: 0.875rem;
  color: #666;
}

.article-category {
  background-color: #f0f0f0;
  color: #666;
  padding: 0.25rem 0.75rem;
  border-radius: 12px;
  font-size: 0.75rem;
  font-weight: 500;
}

.article-title {
  font-size: 1.25rem;
  font-weight: 600;
  color: #000;
  margin-bottom: 0.5rem;
  line-height: 1.3;
}

.article-subtitle {
  color: #666;
  margin-bottom: 1rem;
  font-size: 0.95rem;
}

.article-excerpt {
  color: #666;
  margin-bottom: 1rem;
  line-height: 1.5;
}

.article-footer {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.875rem;
  color: #666;
}

.article-tags {
  display: flex;
  gap: 0.5rem;
}

.tag {
  background-color: #f5f5f5;
  color: #666;
  padding: 0.25rem 0.5rem;
  border-radius: 8px;
  font-size: 0.75rem;
}

.load-more {
  text-align: center;
  margin-top: 2rem;
}

/* Modal */
.modal {
  display: none;
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background-color: rgba(0, 0, 0, 0.5);
  z-index: 1000;
}

.modal-content {
  background-color: #fff;
  margin: 2rem auto;
  padding: 0;
  border-radius: 8px;
  width: 90%;
  max-width: 800px;
  max-height: 90vh;
  overflow-y: auto;
}

.modal-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 1.5rem;
  border-bottom: 1px solid #e6e6e6;
}

.modal-header h3 {
  margin: 0;
  font-size: 1.5rem;
  font-weight: 600;
}

.close-btn {
  background: none;
  border: none;
  font-size: 1.5rem;
  cursor: pointer;
  color: #666;
}

.close-btn:hover {
  color: #000;
}

.modal-body {
  padding: 1.5rem;
}

/* Form Styles */
.form-group {
  margin-bottom: 1.5rem;
}

.form-group label {
  display: block;
  margin-bottom: 0.5rem;
  font-weight: 500;
  color: #333;
}

.form-group input,
.form-group select {
  width: 100%;
  padding: 0.75rem;
  border: 1px solid #e6e6e6;
  border-radius: 4px;
  font-size: 1rem;
  transition: border-color 0.3s ease;
}

.form-group input:focus,
.form-group select:focus {
  outline: none;
  border-color: #000;
}

.editor-toolbar {
  display: flex;
  gap: 0.5rem;
  margin-bottom: 0.5rem;
  padding: 0.5rem;
  background-color: #f5f5f5;
  border-radius: 4px;
}

.editor-toolbar button {
  background: none;
  border: none;
  color: #666;
  cursor: pointer;
  padding: 0.25rem 0.5rem;
  border-radius: 2px;
  transition: all 0.3s ease;
}

.editor-toolbar button:hover {
  background-color: #e6e6e6;
  color: #000;
}

.editor {
  min-height: 300px;
  padding: 1rem;
  border: 1px solid #e6e6e6;
  border-radius: 4px;
  outline: none;
  font-size: 1rem;
  line-height: 1.6;
  resize: vertical;
}

.editor:focus {
  border-color: #000;
}

.editor[contenteditable]:empty::before {
  content: attr(placeholder);
  color: #999;
  font-style: italic;
}

.form-actions {
  display: flex;
  gap: 1rem;
  justify-content: flex-end;
  margin-top: 2rem;
}

/* Footer */
.footer {
  background-color: #fafafa;
  padding: 2rem 0;
  border-top: 1px solid #e6e6e6;
}

.footer-content {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.footer-left {
  color: #666;
  font-size: 0.875rem;
}

.footer-right {
  display: flex;
  gap: 1rem;
}

.footer-right .social-link {
  color: #666;
  font-size: 1.25rem;
  transition: color 0.3s ease;
}

.footer-right .social-link:hover {
  color: #000;
}

/* Book Summaries Page Styles */
.books-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 2rem;
  margin-top: 1rem;
}

.book-card {
  background: white;
  border-radius: 8px;
  padding: 2rem;
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.book-card:hover {
  transform: translateY(-2px);
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.15);
}

.book-meta {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 1rem;
}

.book-category {
  background: #f0f0f0;
  color: #666;
  padding: 0.25rem 0.75rem;
  border-radius: 20px;
  font-size: 0.875rem;
  font-weight: 500;
}

.book-date {
  color: #999;
  font-size: 0.875rem;
}

.book-title {
  font-size: 1.5rem;
  font-weight: 700;
  margin-bottom: 0.5rem;
  color: #2c3e50;
}

.book-author {
  color: #666;
  font-size: 1rem;
  margin-bottom: 1.5rem;
  font-style: italic;
}

.book-summary {
  line-height: 1.6;
}

.book-summary h3 {
  font-size: 1.125rem;
  font-weight: 600;
  margin-top: 1.5rem;
  margin-bottom: 0.75rem;
  color: #2c3e50;
}

.book-summary ul {
  margin: 0.75rem 0;
  padding-left: 1.5rem;
}

.book-summary li {
  margin-bottom: 0.5rem;
  line-height: 1.5;
}

.book-summary li strong {
  color: #2c3e50;
}

.reading-list {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 1.5rem;
  margin-top: 1.5rem;
}

.reading-item {
  background: white;
  border-radius: 8px;
  padding: 1.5rem;
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
  border-left: 4px solid #3498db;
}

.reading-item h3 {
  font-size: 1.125rem;
  font-weight: 600;
  margin-bottom: 0.5rem;
  color: #2c3e50;
}

.reading-author {
  color: #666;
  font-size: 0.875rem;
  margin-bottom: 1rem;
  font-style: italic;
}

.reading-progress {
  background: #3498db;
  color: white;
  padding: 0.25rem 0.75rem;
  border-radius: 20px;
  font-size: 0.75rem;
  font-weight: 500;
}

.section-header {
  text-align: center;
  margin-bottom: 2rem;
}

.section-header h2 {
  font-size: 2rem;
  font-weight: 700;
  margin-bottom: 0.5rem;
  color: #2c3e50;
}

.section-header p {
  font-size: 1.125rem;
  color: #666;
}

/* Patents Page Styles */
.patent-stats {
  display: flex;
  justify-content: center;
  gap: 2rem;
  margin-top: 2rem;
  flex-wrap: wrap;
}

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

.stat-number {
  display: block;
  font-size: 1.5rem;
  font-weight: 700;
  color: #3498db;
  margin-bottom: 0.25rem;
}

.stat-label {
  font-size: 0.875rem;
  color: #666;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.innovation-categories {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 2rem;
  margin: 2rem 0 3rem 0;
}

.category-card {
  background: white;
  border-radius: 8px;
  padding: 2rem;
  text-align: center;
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
  transition: transform 0.2s ease;
}

.category-card:hover {
  transform: translateY(-2px);
}

.category-icon {
  font-size: 2.5rem;
  color: #3498db;
  margin-bottom: 1rem;
}

.category-card h3 {
  font-size: 1.25rem;
  font-weight: 600;
  margin-bottom: 1rem;
  color: #2c3e50;
}

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

.patent-card {
  background: white;
  border-radius: 8px;
  padding: 2rem;
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
  transition: transform 0.2s ease, box-shadow 0.2s ease;
  border-left: 4px solid #3498db;
}

.patent-card:hover {
  transform: translateY(-2px);
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.15);
}

.patent-card.application {
  border-left-color: #f39c12;
}

.patent-meta {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 1rem;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.patent-number {
  background: #3498db;
  color: white;
  padding: 0.25rem 0.75rem;
  border-radius: 20px;
  font-size: 0.875rem;
  font-weight: 500;
  font-family: 'Courier New', monospace;
}

.patent-card.application .patent-number {
  background: #f39c12;
}

.patent-date {
  color: #666;
  font-size: 0.875rem;
  font-weight: 500;
}

.patent-title {
  font-size: 1.25rem;
  font-weight: 600;
  margin-bottom: 1rem;
  color: #2c3e50;
  line-height: 1.4;
}

.patent-details {
  display: flex;
  gap: 1rem;
  margin-bottom: 1rem;
  flex-wrap: wrap;
}

.patent-type {
  background: #e8f5e8;
  color: #27ae60;
  padding: 0.25rem 0.75rem;
  border-radius: 20px;
  font-size: 0.75rem;
  font-weight: 500;
}

.patent-card.application .patent-type {
  background: #fef9e7;
  color: #f39c12;
}

.patent-assignee {
  color: #666;
  font-size: 0.875rem;
  font-weight: 500;
}

.patent-description {
  color: #555;
  line-height: 1.6;
  margin-bottom: 1.5rem;
}

.patent-tech {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.tech-tag {
  background: #f0f0f0;
  color: #666;
  padding: 0.25rem 0.75rem;
  border-radius: 15px;
  font-size: 0.75rem;
  font-weight: 500;
}

.applications-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(400px, 1fr));
  gap: 1.5rem;
  margin-top: 1.5rem;
}

.impact-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 2rem;
  margin-top: 2rem;
}

.impact-item {
  background: white;
  border-radius: 8px;
  padding: 2rem;
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
}

.impact-item h3 {
  font-size: 1.25rem;
  font-weight: 600;
  margin-bottom: 1rem;
  color: #2c3e50;
}

.impact-item p {
  color: #666;
  line-height: 1.6;
}

@media (max-width: 768px) {
  .nav-container {
    flex-direction: column;
    gap: 1rem;
    padding: 1rem 20px;
  }

  .nav-right {
    gap: 1rem;
  }

  .hero-title {
    font-size: 2rem;
  }

  .hero-subtitle {
    font-size: 1.125rem;
  }

  .articles-header {
    flex-direction: column;
    gap: 1rem;
    align-items: flex-start;
  }

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

  .footer-content {
    flex-direction: column;
    gap: 1rem;
    text-align: center;
  }

  .modal-content {
    margin: 1rem auto;
    width: 95%;
  }

  .book-card {
    padding: 1.5rem;
  }
  
  .book-meta {
    flex-direction: column;
    align-items: flex-start;
    gap: 0.5rem;
  }
  
  .book-title {
    font-size: 1.25rem;
  }
  
  .reading-list {
    grid-template-columns: 1fr;
  }

  .patent-stats {
    gap: 1rem;
  }
  
  .stat-number {
    font-size: 1.25rem;
  }
  
  .patent-card {
    padding: 1.5rem;
  }
  
  .patent-meta {
    flex-direction: column;
    align-items: flex-start;
  }
  
  .patent-title {
    font-size: 1.125rem;
  }
  
  .applications-grid {
    grid-template-columns: 1fr;
  }
  
  .innovation-categories {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 480px) {
  .container {
    padding: 0 15px;
  }

  .hero {
    padding: 2rem 0;
  }

  .articles {
    padding: 2rem 0;
  }

  .modal-content {
    margin: 0.5rem auto;
    width: 98%;
  }
}