:root {
  /* Light Theme Variables */
  --bg-primary: #ffffff;
  --bg-secondary: #f8f9fa;
  --bg-accent: #e9ecef;
  --text-primary: #212529;
  --text-secondary: #6c757d;
  --text-muted: #adb5bd;
  --border-color: #dee2e6;
  --shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
  --shadow-hover: 0 4px 20px rgba(0, 0, 0, 0.15);
  --accent-primary: #007bff;
  --accent-success: #28a745;
  --accent-danger: #dc3545;
  --accent-warning: #ffc107;
}

[data-theme="dark"] {
  /* Dark Theme Variables */
  --bg-primary: #1a1a1a;
  --bg-secondary: #2d2d2d;
  --bg-accent: #3a3a3a;
  --text-primary: #ffffff;
  --text-secondary: #b0b0b0;
  --text-muted: #6c757d;
  --border-color: #404040;
  --shadow: 0 2px 10px rgba(0, 0, 0, 0.3);
  --shadow-hover: 0 4px 20px rgba(0, 0, 0, 0.4);
  --accent-primary: #0d6efd;
  --accent-success: #198754;
  --accent-danger: #dc3545;
  --accent-warning: #fd7e14;
}

/* Global Styles */
* {
  box-sizing: border-box;
}

body {
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  margin: 0;
  padding: 0;
  background-color: var(--bg-secondary);
  color: var(--text-primary);
  transition: background-color 0.3s ease, color 0.3s ease;
  line-height: 1.6;
}

/* Theme Toggle */
.theme-toggle-container {
  position: fixed;
  top: 20px;
  right: 20px;
  z-index: 1000;
}

.theme-toggle-btn {
  background: var(--bg-primary);
  border: 2px solid var(--border-color);
  border-radius: 50px;
  width: 60px;
  height: 32px;
  cursor: pointer;
  position: relative;
  transition: all 0.3s ease;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 4px;
  box-shadow: var(--shadow);
}

.theme-toggle-btn:hover {
  box-shadow: var(--shadow-hover);
  transform: translateY(-1px);
}

.theme-toggle-btn i {
  font-size: 12px;
  transition: opacity 0.3s ease;
  z-index: 2;
}

[data-theme="light"] .theme-toggle-btn .fa-sun {
  opacity: 1;
  color: var(--accent-warning);
}

[data-theme="light"] .theme-toggle-btn .fa-moon {
  opacity: 0.3;
  color: var(--text-muted);
}

[data-theme="dark"] .theme-toggle-btn .fa-sun {
  opacity: 0.3;
  color: var(--text-muted);
}

[data-theme="dark"] .theme-toggle-btn .fa-moon {
  opacity: 1;
  color: var(--accent-primary);
}

/* Main Layout */
.container {
  max-width: 1400px;
  margin: 0 auto;
  padding: 20px;
  padding-top: 80px;
}

/* Header */
.app-header {
  text-align: center;
  margin-bottom: 40px;
}

.app-title {
  font-size: 3rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 10px;
  background: linear-gradient(135deg, var(--accent-primary), var(--accent-success));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.app-subtitle {
  font-size: 1.2rem;
  color: var(--text-secondary);
  margin: 0;
}

/* Filter Panel */
.filter-panel {
  background: var(--bg-primary);
  border-radius: 12px;
  padding: 30px;
  margin-bottom: 30px;
  box-shadow: var(--shadow);
  border: 1px solid var(--border-color);
}

.filter-header {
  margin-bottom: 25px;
}

.filter-header h3 {
  color: var(--text-primary);
  font-size: 1.5rem;
  margin-bottom: 5px;
  display: flex;
  align-items: center;
  gap: 10px;
}

.filter-help {
  color: var(--text-secondary);
  font-style: italic;
}

/* Filter Expression Input */
.filter-expression-container {
  margin-bottom: 20px;
}

.filter-expression-input {
  width: 100%;
  background: var(--bg-primary);
  border: 2px solid var(--border-color);
  border-radius: 8px;
  padding: 15px;
  font-family: 'Courier New', monospace;
  font-size: 1rem;
  color: var(--text-primary);
  resize: vertical;
  min-height: 80px;
  transition: border-color 0.3s ease, box-shadow 0.3s ease;
}

.filter-expression-input:focus {
  outline: none;
  border-color: var(--accent-primary);
  box-shadow: 0 0 0 3px rgba(13, 110, 253, 0.25);
}

.filter-expression-input::placeholder {
  color: var(--text-muted);
  font-style: italic;
}

.filter-expression-help {
  margin-top: 8px;
  padding: 8px 12px;
  background: var(--bg-accent);
  border-radius: 6px;
  border-left: 4px solid var(--accent-primary);
}

.filter-expression-help small {
  color: var(--text-secondary);
  line-height: 1.4;
}

.filter-expression-help code {
  background: var(--bg-primary);
  padding: 2px 6px;
  border-radius: 4px;
  font-family: 'Courier New', monospace;
  color: var(--accent-primary);
  font-weight: 600;
}

.filter-token {
  background: var(--accent-primary);
  color: white;
  padding: 6px 12px;
  border-radius: 20px;
  font-size: 0.9rem;
  display: inline-flex;
  align-items: center;
  gap: 6px;
  cursor: pointer;
  transition: all 0.2s ease;
}

.filter-token:hover {
  background: var(--accent-danger);
  transform: translateY(-1px);
}

.filter-token .remove-token {
  cursor: pointer;
  font-weight: bold;
}

.operator-token {
  background: var(--accent-success);
  color: white;
  padding: 6px 12px;
  border-radius: 20px;
  font-size: 0.9rem;
  font-weight: bold;
}

/* Filter Controls */
.filter-controls {
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.add-filter-section {
  display: flex;
  gap: 10px;
  align-items: center;
  flex-wrap: wrap;
}

.genre-dropdown {
  flex: 1;
  min-width: 250px;
  padding: 10px 15px;
  border: 2px solid var(--border-color);
  border-radius: 8px;
  background: var(--bg-primary);
  color: var(--text-primary);
  font-size: 1rem;
  transition: border-color 0.3s ease;
}

.genre-dropdown:focus {
  outline: none;
  border-color: var(--accent-primary);
  box-shadow: 0 0 0 3px rgba(13, 110, 253, 0.25);
}

.logic-operators {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
}

.logic-btn {
  background: var(--bg-accent);
  border: 2px solid var(--border-color);
  color: var(--text-primary);
  padding: 8px 16px;
  border-radius: 6px;
  cursor: pointer;
  font-weight: 600;
  transition: all 0.3s ease;
}

.logic-btn:hover {
  background: var(--accent-primary);
  color: white;
  border-color: var(--accent-primary);
  transform: translateY(-1px);
}

.filter-actions {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
}

/* Additional Filters */
.additional-filters {
  margin-top: 25px;
  padding-top: 25px;
  border-top: 1px solid var(--border-color);
}

.rating-filter {
  display: flex;
  align-items: center;
  gap: 15px;
}

.rating-filter label {
  color: var(--text-primary);
  font-weight: 500;
  min-width: 140px;
}

.rating-filter input {
  width: 120px;
  padding: 8px 12px;
  border: 2px solid var(--border-color);
  border-radius: 6px;
  background: var(--bg-primary);
  color: var(--text-primary);
}

.rating-filter input:focus {
  outline: none;
  border-color: var(--accent-primary);
  box-shadow: 0 0 0 3px rgba(13, 110, 253, 0.25);
}

/* Results Panel */
.results-panel {
  background: var(--bg-primary);
  border-radius: 12px;
  padding: 30px;
  margin-bottom: 30px;
  box-shadow: var(--shadow);
  border: 1px solid var(--border-color);
}

.results-header {
  margin-bottom: 25px;
}

.results-stats {
  display: flex;
  gap: 30px;
  flex-wrap: wrap;
}

.stat-item {
  background: var(--bg-accent);
  padding: 12px 20px;
  border-radius: 8px;
  font-weight: 600;
  color: var(--text-primary);
  border: 1px solid var(--border-color);
}

/* Table Styles */
.table-container {
  overflow-x: auto;
  border-radius: 8px;
  border: 1px solid var(--border-color);
}

.books-table {
  width: 100%;
  border-collapse: collapse;
  background: var(--bg-primary);
}

.books-table th {
  background: var(--bg-accent);
  color: var(--text-primary);
  padding: 15px 12px;
  text-align: left;
  font-weight: 600;
  border-bottom: 2px solid var(--border-color);
  position: sticky;
  top: 0;
}

.books-table th i {
  margin-right: 8px;
  color: var(--accent-primary);
}

.books-table td {
  padding: 12px;
  border-bottom: 1px solid var(--border-color);
  color: var(--text-primary);
}

.books-table tr:hover {
  background: var(--bg-accent);
}

.books-table a {
  color: var(--accent-primary);
  text-decoration: none;
  font-weight: 500;
  transition: color 0.3s ease;
}

.books-table a:hover {
  color: var(--accent-success);
  text-decoration: underline;
}

/* Genre Tags */
.genre-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 4px;
}

.genre-tag {
  background: var(--accent-primary);
  color: white;
  padding: 2px 8px;
  border-radius: 12px;
  font-size: 0.8rem;
  font-weight: 500;
}

/* Rating Badge */
.rating-badge {
  background: var(--accent-success);
  color: white;
  padding: 4px 8px;
  border-radius: 6px;
  font-weight: 600;
  font-size: 0.9rem;
}

/* Pagination */
.pagination-nav {
  margin-top: 30px;
}

.pagination {
  display: flex;
  justify-content: center;
  gap: 5px;
  flex-wrap: wrap;
}

.pagination .page-item .page-link {
  background: var(--bg-primary);
  border: 2px solid var(--border-color);
  color: var(--text-primary);
  padding: 10px 15px;
  border-radius: 8px;
  text-decoration: none;
  transition: all 0.3s ease;
  font-weight: 500;
}

.pagination .page-item .page-link:hover {
  background: var(--accent-primary);
  color: white;
  border-color: var(--accent-primary);
  transform: translateY(-1px);
}

.pagination .page-item.active .page-link {
  background: var(--accent-primary);
  color: white;
  border-color: var(--accent-primary);
}

/* Button Styles */
.btn {
  padding: 10px 20px;
  border: none;
  border-radius: 6px;
  cursor: pointer;
  font-weight: 500;
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  transition: all 0.3s ease;
  font-size: 0.95rem;
}

.btn:hover {
  transform: translateY(-1px);
  box-shadow: var(--shadow-hover);
}

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

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

.btn-outline-secondary {
  background: transparent;
  color: var(--text-secondary);
  border: 2px solid var(--border-color);
}

.btn-outline-secondary:hover {
  background: var(--accent-danger);
  color: white;
  border-color: var(--accent-danger);
}

/* Responsive Design */
@media (max-width: 768px) {
  .container {
    padding: 15px;
    padding-top: 70px;
  }
  
  .app-title {
    font-size: 2rem;
  }
  
  .filter-panel,
  .results-panel {
    padding: 20px;
  }
  
  .add-filter-section {
    flex-direction: column;
    align-items: stretch;
  }
  
  .genre-dropdown {
    min-width: auto;
  }
  
  .results-stats {
    flex-direction: column;
    gap: 15px;
  }
  
  .books-table {
    font-size: 0.9rem;
  }
  
  .books-table th,
  .books-table td {
    padding: 8px 6px;
  }
}