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

:root {
  --primary-color: #0071BC;
  --background: #ffffff;
  --text-primary: #333333;
  --text-secondary: #666666;
  --border-color: #e0e0e0;
  --shadow: 0 2px 4px rgba(0,0,0,0.1);
  --spacing-sm: 8px;
  --spacing-md: 16px;
  --spacing-lg: 24px;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, sans-serif;
  background: var(--background);
  color: var(--text-primary);
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
}

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

.header {
  background: var(--background);
  border-bottom: 1px solid var(--border-color);
  padding: var(--spacing-md) 0;
  position: sticky;
  top: 0;
  z-index: 100;
  box-shadow: var(--shadow);
}

.header h1 {
  font-size: 1.25rem;
  font-weight: 600;
}

.search-container {
  margin-top: var(--spacing-sm);
}

.search-input {
  width: 100%;
  padding: var(--spacing-sm);
  border: 1px solid var(--border-color);
  border-radius: 4px;
  font-size: 1rem;
}

.filter-bar {
  display: flex;
  gap: var(--spacing-sm);
  flex-wrap: wrap;
  margin-top: var(--spacing-sm);
}

.filter-select {
  padding: var(--spacing-sm);
  border: 1px solid var(--border-color);
  border-radius: 4px;
  font-size: 0.875rem;
  background: var(--background);
  flex: 1;
  min-width: 120px;
}

.category {
  margin-bottom: var(--spacing-lg);
}

.category-header {
  font-size: 1.125rem;
  font-weight: 600;
  margin-bottom: var(--spacing-md);
  padding-bottom: var(--spacing-sm);
  border-bottom: 2px solid var(--primary-color);
}

.subcategory {
  margin-bottom: var(--spacing-md);
}

.subcategory-header {
  font-size: 1rem;
  font-weight: 500;
  margin-bottom: var(--spacing-sm);
  padding-left: var(--spacing-md);
}

.books-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(150px, 1fr));
  gap: var(--spacing-md);
  padding-left: var(--spacing-md);
}

.book-card {
  background: var(--background);
  border: 1px solid var(--border-color);
  border-radius: 8px;
  overflow: hidden;
  cursor: pointer;
  transition: transform 0.2s, box-shadow 0.2s;
  text-decoration: none;
  color: var(--text-primary);
}

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

.book-cover {
  width: 100%;
  aspect-ratio: 3/4;
  object-fit: cover;
  background: #f5f5f5;
}

.book-info {
  padding: var(--spacing-sm);
}

.book-title {
  font-size: 0.875rem;
  font-weight: 500;
  margin-bottom: var(--spacing-sm);
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.book-meta {
  font-size: 0.75rem;
  color: var(--text-secondary);
}

.no-results {
  text-align: center;
  padding: var(--spacing-lg);
  color: var(--text-secondary);
}

.loading {
  text-align: center;
  padding: var(--spacing-lg);
  color: var(--text-secondary);
}

.reader-container {
  max-width: 100%;
  margin: 0;
  padding: 0;
  background: #1a1a1a;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

.reader-header {
  background: #2a2a2a;
  color: white;
  padding: var(--spacing-sm);
  display: flex;
  justify-content: space-between;
  align-items: center;
  position: sticky;
  top: 0;
  z-index: 100;
}

.back-button {
  background: none;
  border: none;
  color: white;
  font-size: 0.875rem;
  cursor: pointer;
  padding: var(--spacing-sm);
}

.page-counter {
  font-size: 0.875rem;
}

.reader-content {
  flex: 1;
  display: flex;
  justify-content: center;
  align-items: center;
  overflow: hidden;
  position: relative;
  touch-action: pan-y;
}

.page-image {
  max-width: 100%;
  max-height: 100vh;
  object-fit: contain;
  user-select: none;
}

.page-loading {
  color: #888;
  font-size: 0.875rem;
}

.page-error {
  color: #ff4444;
  font-size: 0.875rem;
  padding: var(--spacing-md);
}

.navigation-controls {
  position: absolute;
  bottom: var(--spacing-md);
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  gap: var(--spacing-md);
  background: rgba(0,0,0,0.7);
  padding: var(--spacing-sm);
  border-radius: 20px;
}

.nav-button {
  background: white;
  border: none;
  padding: var(--spacing-sm) var(--spacing-md);
  border-radius: 4px;
  cursor: pointer;
  font-size: 0.875rem;
  font-weight: 500;
}

.nav-button:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

@media (max-width: 600px) {
  .container {
    padding: var(--spacing-sm);
  }
  
  .books-grid {
    grid-template-columns: repeat(auto-fill, minmax(100px, 1fr));
    gap: var(--spacing-sm);
  }
  
  .book-cover {
    aspect-ratio: 3/4;
  }
  
  .filter-bar {
    flex-direction: column;
  }
  
  .filter-select {
    width: 100%;
  }
  
  .navigation-controls {
    bottom: var(--spacing-sm);
  }
  
  .nav-button {
    padding: var(--spacing-sm) var(--spacing-lg);
  }
}