:root {
  --color-primary: #2196F3;
  --color-primary-hover: #1976D2;
  --color-bg-light: #f5f5f5;
  --color-bg-white: #ffffff;
  --color-border: #e0e0e0;
  --color-text-primary: #333333;
  --color-text-secondary: #666666;
  --color-text-tertiary: #999999;
  --spacing-xs: 4px;
  --spacing-sm: 8px;
  --spacing-md: 16px;
  --spacing-lg: 24px;
  --spacing-xl: 32px;
  --spacing-xxl: 48px;
  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-full: 50%;
  --shadow-light: 0 2px 8px rgba(0, 0, 0, 0.05);
  --shadow-medium: 0 4px 16px rgba(0, 0, 0, 0.1);
  --shadow-strong: 0 8px 24px rgba(0, 0, 0, 0.15);
}

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

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', sans-serif;
  background-color: var(--color-bg-light);
  color: var(--color-text-primary);
  line-height: 1.6;
  min-height: 100vh;
}

h1 {
  font-size: 32px;
  font-weight: 600;
  line-height: 1.2;
  color: var(--color-text-primary);
}

h2 {
  font-size: 24px;
  font-weight: 600;
  line-height: 1.3;
  color: var(--color-text-primary);
  margin-bottom: 20px;
}

h3 {
  font-size: 18px;
  font-weight: 600;
  line-height: 1.4;
  color: var(--color-text-primary);
  margin-bottom: 12px;
}

p {
  font-size: 16px;
  font-weight: 400;
  line-height: 1.6;
  color: var(--color-text-primary);
}

.text-small {
  font-size: 14px;
  font-weight: 400;
  line-height: 1.5;
  color: var(--color-text-secondary);
}

.text-tertiary {
  font-size: 12px;
  font-weight: 400;
  line-height: 1.4;
  color: var(--color-text-tertiary);
}

a {
  color: var(--color-primary);
  text-decoration: none;
  transition: color 0.2s ease;
}

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

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--spacing-lg);
}

.card {
  background: var(--color-bg-white);
  border-radius: var(--radius-md);
  padding: var(--spacing-lg);
  box-shadow: var(--shadow-light);
  transition: box-shadow 0.2s ease;
}

.card:hover {
  box-shadow: var(--shadow-medium);
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 8px 20px;
  background: var(--color-primary);
  color: white;
  border: none;
  border-radius: var(--radius-sm);
  font-size: 14px;
  font-weight: 500;
  cursor: pointer;
  transition: background 0.2s ease;
}

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

.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  background: var(--color-bg-white);
  border-bottom: 1px solid var(--color-border);
  z-index: 1000;
  height: 64px;
}

.navbar-content {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--spacing-lg);
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.navbar-logo {
  font-size: 20px;
  font-weight: 600;
  color: var(--color-text-primary);
  text-decoration: none;
}

.nav-links {
  display: flex;
  gap: var(--spacing-lg);
}

.nav-link {
  color: var(--color-text-secondary);
  text-decoration: none;
  font-size: 16px;
  font-weight: 500;
  padding: 8px 0;
  position: relative;
  transition: color 0.2s ease;
}

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

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

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

.navbar-toggle {
  display: none;
  background: none;
  border: none;
  font-size: 24px;
  cursor: pointer;
  color: var(--color-text-primary);
}

.nav-menu-mobile {
  display: none;
  position: absolute;
  top: 64px;
  left: 0;
  right: 0;
  background: var(--color-bg-white);
  border-bottom: 1px solid var(--color-border);
  padding: var(--spacing-md);
}

.nav-menu-mobile.show {
  display: block;
}

.nav-menu-mobile .nav-link {
  display: block;
  padding: var(--spacing-md) 0;
}

.home-container {
  min-height: 100vh;
  padding-top: 64px;
  padding-bottom: var(--spacing-xxl);
}

.profile-section {
  text-align: center;
  padding-top: var(--spacing-xxl);
  padding-bottom: var(--spacing-xl);
}

.profile-avatar {
  width: 120px;
  height: 120px;
  border-radius: var(--radius-full);
  object-fit: cover;
  border: 4px solid var(--color-bg-white);
  box-shadow: var(--shadow-light);
  margin-bottom: var(--spacing-lg);
}

.profile-name {
  font-size: 32px;
  font-weight: 600;
  color: var(--color-text-primary);
  margin-bottom: var(--spacing-sm);
}

.profile-bio {
  font-size: 18px;
  color: var(--color-text-secondary);
  margin-bottom: var(--spacing-md);
}

.profile-contact {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-lg);
  font-size: 14px;
  color: var(--color-text-secondary);
}

.profile-contact a {
  display: flex;
  align-items: center;
  gap: var(--spacing-xs);
}

.categories-section {
  max-width: 800px;
  margin: 0 auto;
  padding: 0 var(--spacing-lg);
}

.categories-title {
  font-size: 24px;
  font-weight: 600;
  color: var(--color-text-primary);
  margin-bottom: var(--spacing-lg);
  text-align: center;
}

.categories-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--spacing-lg);
}

.category-card {
  background: var(--color-bg-white);
  border-radius: var(--radius-md);
  padding: var(--spacing-xl);
  text-align: center;
  border: 1px solid var(--color-border);
  cursor: pointer;
  transition: all 0.2s ease;
}

.category-card:hover {
  box-shadow: var(--shadow-medium);
  border-color: var(--color-primary);
  transform: translateY(-2px);
}

.category-icon {
  font-size: 32px;
  margin-bottom: var(--spacing-sm);
}

.category-name {
  font-size: 18px;
  font-weight: 600;
  color: var(--color-text-primary);
  margin-bottom: var(--spacing-xs);
}

.category-count {
  font-size: 14px;
  color: var(--color-text-tertiary);
}

.category-container {
  min-height: 100vh;
  padding-top: 64px;
  padding-bottom: var(--spacing-xxl);
}

.page-header {
  text-align: center;
  padding: var(--spacing-xl) var(--spacing-lg) var(--spacing-lg);
}

.page-title {
  font-size: 32px;
  font-weight: 600;
  color: var(--color-text-primary);
  margin-bottom: var(--spacing-sm);
}

.page-subtitle {
  font-size: 14px;
  color: var(--color-text-tertiary);
}

.search-container {
  max-width: 600px;
  margin: 0 auto var(--spacing-lg);
  position: relative;
}

.search-input {
  width: 100%;
  padding: 12px 40px 12px 16px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  font-size: 16px;
  color: var(--color-text-primary);
  background: var(--color-bg-white);
  transition: border-color 0.2s ease, box-shadow 0.2s ease;
}

.search-input::placeholder {
  color: var(--color-text-tertiary);
}

.search-input:focus {
  outline: none;
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px rgba(33, 150, 243, 0.1);
}

.search-icon {
  position: absolute;
  right: 12px;
  top: 50%;
  transform: translateY(-50%);
  color: var(--color-text-tertiary);
  pointer-events: none;
}

.search-clear {
  position: absolute;
  right: 12px;
  top: 50%;
  transform: translateY(-50%);
  background: none;
  border: none;
  color: var(--color-text-tertiary);
  cursor: pointer;
  font-size: 18px;
  display: none;
}

.search-clear.show {
  display: block;
}

.search-clear:hover {
  color: var(--color-text-secondary);
}

.content-section {
  max-width: 800px;
  margin: 0 auto;
  padding: 0 var(--spacing-lg);
}

.content-list {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-md);
}

.note-card {
  background: var(--color-bg-white);
  border-radius: var(--radius-md);
  padding: var(--spacing-lg);
  border: 1px solid var(--color-border);
  transition: all 0.2s ease;
  cursor: pointer;
}

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

.note-tags {
  display: flex;
  gap: var(--spacing-xs);
  margin-bottom: var(--spacing-sm);
  flex-wrap: wrap;
}

.note-tag {
  padding: 4px 12px;
  background: var(--color-bg-light);
  color: var(--color-text-secondary);
  font-size: 12px;
  border-radius: var(--radius-sm);
}

.note-title {
  font-size: 18px;
  font-weight: 600;
  color: var(--color-text-primary);
  margin-bottom: var(--spacing-sm);
  transition: color 0.2s ease;
}

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

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

.note-date {
  font-size: 14px;
  color: var(--color-text-tertiary);
}

.note-link {
  display: inline-flex;
  align-items: center;
  gap: var(--spacing-xs);
  color: var(--color-primary);
  font-size: 14px;
  font-weight: 500;
  text-decoration: none;
  transition: all 0.2s ease;
}

.note-link:hover {
  color: var(--color-primary-hover);
}

.note-link-arrow {
  transition: transform 0.2s ease;
}

.note-card:hover .note-link-arrow {
  transform: translateX(4px);
}

.project-card {
  background: var(--color-bg-white);
  border-radius: var(--radius-md);
  padding: var(--spacing-lg);
  border: 1px solid var(--color-border);
  transition: all 0.2s ease;
}

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

.project-header {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  margin-bottom: var(--spacing-md);
}

.project-title {
  font-size: 20px;
  font-weight: 600;
  color: var(--color-text-primary);
  margin-bottom: var(--spacing-xs);
}

.project-description {
  font-size: 14px;
  color: var(--color-text-secondary);
  line-height: 1.6;
  margin-bottom: var(--spacing-md);
}

.project-tech-stack {
  display: flex;
  flex-wrap: wrap;
  gap: var(--spacing-xs);
  margin-bottom: var(--spacing-md);
}

.tech-tag {
  padding: 4px 12px;
  background: var(--color-bg-light);
  color: var(--color-text-secondary);
  font-size: 12px;
  border-radius: var(--radius-sm);
}

.project-link {
  display: inline-flex;
  align-items: center;
  gap: var(--spacing-xs);
  padding: 8px 20px;
  background: var(--color-primary);
  color: white;
  border-radius: var(--radius-sm);
  text-decoration: none;
  font-size: 14px;
  font-weight: 500;
  transition: background 0.2s ease;
}

.project-link:hover {
  background: var(--color-primary-hover);
}

.project-link-arrow {
  transition: transform 0.2s ease;
}

.project-card:hover .project-link-arrow {
  transform: translateX(4px);
}

.mindmaps-section {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--spacing-lg);
}

.mindmaps-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: var(--spacing-lg);
}

.mindmap-card {
  background: var(--color-bg-white);
  border-radius: var(--radius-md);
  overflow: hidden;
  border: 1px solid var(--color-border);
  cursor: pointer;
  transition: all 0.2s ease;
}

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

.mindmap-thumbnail {
  width: 100%;
  height: 200px;
  object-fit: cover;
  display: block;
  background: var(--color-bg-light);
}

.mindmap-info {
  padding: var(--spacing-md);
}

.mindmap-title {
  font-size: 16px;
  font-weight: 600;
  color: var(--color-text-primary);
  margin-bottom: var(--spacing-xs);
  line-height: 1.4;
}

.mindmap-date {
  font-size: 12px;
  color: var(--color-text-tertiary);
}

.modal {
  display: none;
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: rgba(0, 0, 0, 0.8);
  z-index: 2000;
  align-items: center;
  justify-content: center;
  padding: var(--spacing-lg);
}

.modal.show {
  display: flex;
}

.modal-content {
  max-width: 90%;
  max-height: 90%;
  position: relative;
}

.modal-image {
  max-width: 100%;
  max-height: 90vh;
  object-fit: contain;
  border-radius: var(--radius-md);
}

.modal-close {
  position: absolute;
  top: -40px;
  right: 0;
  background: none;
  border: none;
  color: white;
  font-size: 32px;
  cursor: pointer;
  transition: opacity 0.2s ease;
}

.modal-close:hover {
  opacity: 0.7;
}

.empty-state {
  text-align: center;
  padding: var(--spacing-xxl) var(--spacing-lg);
}

.empty-state-icon {
  font-size: 48px;
  margin-bottom: var(--spacing-md);
}

.empty-state-text {
  font-size: 16px;
  color: var(--color-text-secondary);
}

.pagination {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: var(--spacing-sm);
  margin-top: var(--spacing-lg);
}

.pagination-btn {
  padding: 8px 16px;
  background: var(--color-bg-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  color: var(--color-text-primary);
  cursor: pointer;
  transition: all 0.2s ease;
}

.pagination-btn:hover:not(:disabled) {
  background: var(--color-primary);
  color: white;
  border-color: var(--color-primary);
}

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

.pagination-info {
  font-size: 14px;
  color: var(--color-text-secondary);
}

@media (max-width: 768px) {
  .nav-links {
    display: none;
  }

  .navbar-toggle {
    display: block;
  }

  .categories-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .mindmaps-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .project-header {
    flex-direction: column;
    gap: var(--spacing-sm);
  }

  .project-title {
    font-size: 18px;
  }

  .project-link {
    width: 100%;
    justify-content: center;
  }
}

@media (max-width: 480px) {
  .categories-grid {
    grid-template-columns: 1fr;
  }

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

  .mindmap-thumbnail {
    height: 180px;
  }

  .profile-name {
    font-size: 24px;
  }

  .profile-bio {
    font-size: 16px;
  }

  .profile-contact {
    flex-direction: column;
    gap: var(--spacing-sm);
  }
}

@keyframes fadeIn {
  from {
    opacity: 0;
  }
  to {
    opacity: 1;
  }
}

.fade-in {
  animation: fadeIn 0.3s ease-out;
}

.loading-state {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: var(--spacing-xxl);
  gap: var(--spacing-md);
}

.loading-spinner {
  width: 40px;
  height: 40px;
  border: 4px solid var(--color-border);
  border-top-color: var(--color-primary);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
}

@keyframes spin {
  to {
    transform: rotate(360deg);
  }
}

.loading-text {
  font-size: 14px;
  color: var(--color-text-secondary);
}

.note-description {
  font-size: 16px;
  color: var(--color-text-secondary);
  line-height: 1.8;
  margin-bottom: var(--spacing-md);
}

.mindmap-detail {
  background: var(--color-bg-white);
  border-radius: var(--radius-md);
  padding: var(--spacing-lg);
  border: 1px solid var(--color-border);
}

.mindmap-image-container {
  margin: var(--spacing-lg) 0;
  text-align: center;
}

.mindmap-full-image {
  max-width: 100%;
  height: auto;
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-light);
}