/* ==========================================================================
   NerdySelf - Clean & Simple Book List App Styling
   ========================================================================== */

:root {
  --font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  
  /* Color Palette */
  --color-primary: #4f46e5;
  --color-primary-hover: #4338ca;
  --color-primary-subtle: #eef2ff;
  
  --color-bg: #f8fafc;
  --color-surface: #ffffff;
  --color-border: #e2e8f0;
  --color-border-hover: #cbd5e1;
  
  --color-text-main: #0f172a;
  --color-text-muted: #64748b;
  --color-text-light: #94a3b8;
  
  --color-read-text: #065f46;
  --color-read-bg: #d1fae5;
  --color-read-border: #a7f3d0;
  
  --color-unread-text: #92400e;
  --color-unread-bg: #fef3c7;
  --color-unread-border: #fde68a;
  
  --color-danger: #dc2626;
  --color-danger-hover: #b91c1c;
  --color-danger-subtle: #fef2f2;
  
  /* Shadows */
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.07), 0 2px 4px -2px rgba(0, 0, 0, 0.05);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.08), 0 4px 6px -4px rgba(0, 0, 0, 0.04);
  
  /* Radius */
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
  --radius-full: 9999px;
  
  /* Transitions */
  --transition-fast: 150ms ease;
  --transition-normal: 220ms ease;
}

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

body {
  font-family: var(--font-family);
  background-color: var(--color-bg);
  color: var(--color-text-main);
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
  min-height: 100vh;
  padding: 16px;
}

/* Responsive Container */
.app-container {
  width: 100%;
  max-width: 680px;
  margin: 0 auto;
  padding-bottom: 40px;
}

/* ==========================================================================
   Header & Stats Bar
   ========================================================================== */
.app-header {
  margin-bottom: 24px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 16px;
}

.brand-icon {
  width: 44px;
  height: 44px;
  border-radius: var(--radius-md);
  background: var(--color-primary);
  color: #ffffff;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: var(--shadow-sm);
  flex-shrink: 0;
}

.brand-title {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--color-text-main);
  letter-spacing: -0.02em;
}

.brand-subtitle {
  font-size: 0.875rem;
  color: var(--color-text-muted);
}

/* Stats Card (Total Books prominently shown) */
.stats-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 14px 18px;
  display: flex;
  align-items: center;
  justify-content: space-around;
  box-shadow: var(--shadow-sm);
}

.stat-item {
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  flex: 1;
}

.stat-number {
  font-size: 1.5rem;
  font-weight: 700;
  line-height: 1.2;
}

.stat-label {
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  font-weight: 600;
  color: var(--color-text-muted);
  margin-top: 2px;
}

.stat-item.total .stat-number {
  color: var(--color-primary);
}

.stat-item.read .stat-number {
  color: var(--color-read-text);
}

.stat-item.unread .stat-number {
  color: var(--color-unread-text);
}

.stat-divider {
  width: 1px;
  height: 32px;
  background-color: var(--color-border);
}

/* ==========================================================================
   Cards & Form Styles
   ========================================================================== */
.card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 20px;
  box-shadow: var(--shadow-sm);
  margin-bottom: 20px;
}

.card-title {
  font-size: 1.1rem;
  font-weight: 600;
  display: flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 16px;
  color: var(--color-text-main);
}

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

.form-group {
  margin-bottom: 16px;
}

label, .field-label-text {
  display: block;
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--color-text-main);
  margin-bottom: 6px;
}

.required {
  color: var(--color-danger);
}

input[type="text"],
input[type="search"] {
  width: 100%;
  padding: 12px 14px;
  font-size: 0.95rem;
  font-family: inherit;
  color: var(--color-text-main);
  background-color: #ffffff;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  outline: none;
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

input[type="text"]:focus,
input[type="search"]:focus {
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px rgba(79, 70, 229, 0.15);
}

input::placeholder {
  color: var(--color-text-light);
}

/* Toggle Switch Control */
.toggle-control {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  cursor: pointer;
  user-select: none;
  font-weight: normal;
  margin-bottom: 0;
  padding: 4px 0;
}

.toggle-control input[type="checkbox"] {
  position: absolute;
  opacity: 0;
  width: 0;
  height: 0;
}

.toggle-track {
  width: 44px;
  height: 24px;
  background-color: #cbd5e1;
  border-radius: var(--radius-full);
  position: relative;
  transition: background-color var(--transition-fast);
  flex-shrink: 0;
}

.toggle-track::before {
  content: "";
  position: absolute;
  top: 2px;
  left: 2px;
  width: 20px;
  height: 20px;
  background-color: #ffffff;
  border-radius: 50%;
  box-shadow: var(--shadow-sm);
  transition: transform var(--transition-fast);
}

.toggle-control input:checked + .toggle-track {
  background-color: #10b981;
}

.toggle-control input:checked + .toggle-track::before {
  transform: translateX(20px);
}

.toggle-control input:focus-visible + .toggle-track {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

.toggle-text {
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--color-text-main);
}

/* ==========================================================================
   Star Rating Picker
   ========================================================================== */
.star-rating-control {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-wrap: wrap;
  padding: 4px 0;
}

.stars-picker {
  display: inline-flex;
  align-items: center;
  gap: 2px;
}

.star-btn {
  background: none;
  border: none;
  font-size: 1.6rem;
  line-height: 1;
  color: #cbd5e1;
  cursor: pointer;
  padding: 2px 4px;
  border-radius: var(--radius-sm);
  transition: color var(--transition-fast), transform var(--transition-fast);
  touch-action: manipulation;
}

.star-btn:hover,
.star-btn.active,
.star-btn.hover-active {
  color: #f59e0b;
}

.star-btn:hover {
  transform: scale(1.15);
}

.star-btn:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

.rating-value-label {
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--color-text-muted);
  min-width: 80px;
}

.rating-clear-btn {
  background: #f1f5f9;
  border: none;
  border-radius: 50%;
  width: 24px;
  height: 24px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-size: 1.1rem;
  line-height: 1;
  color: var(--color-text-muted);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.rating-clear-btn:hover {
  background: #e2e8f0;
  color: var(--color-danger);
}

/* ==========================================================================
   Buttons
   ========================================================================== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 18px;
  font-size: 0.95rem;
  font-weight: 600;
  font-family: inherit;
  border-radius: var(--radius-md);
  border: 1px solid transparent;
  cursor: pointer;
  transition: all var(--transition-fast);
  text-decoration: none;
  min-height: 44px; /* Touch-friendly tap target */
}

.btn-primary {
  width: 100%;
  background-color: var(--color-primary);
  color: #ffffff;
}

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

.btn-primary:active {
  transform: scale(0.99);
}

.btn-secondary {
  background-color: var(--color-bg);
  border-color: var(--color-border);
  color: var(--color-text-main);
}

.btn-secondary:hover {
  background-color: #e2e8f0;
}

.btn-danger {
  background-color: var(--color-danger);
  color: #ffffff;
}

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

/* ==========================================================================
   Search & Filter Section
   ========================================================================== */
.search-section {
  margin-bottom: 20px;
}

.search-bar {
  position: relative;
  display: flex;
  align-items: center;
  margin-bottom: 12px;
}

.search-icon {
  position: absolute;
  left: 14px;
  color: var(--color-text-light);
  pointer-events: none;
}

.search-bar input[type="search"] {
  padding-left: 42px;
  padding-right: 40px;
  border-radius: var(--radius-md);
  background-color: var(--color-surface);
}

.clear-search-btn {
  position: absolute;
  right: 10px;
  background: none;
  border: none;
  font-size: 1.3rem;
  color: var(--color-text-muted);
  cursor: pointer;
  padding: 4px 8px;
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  line-height: 1;
}

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

/* Filter Tabs */
.filter-tabs {
  display: flex;
  gap: 8px;
  background-color: #f1f5f9;
  padding: 4px;
  border-radius: var(--radius-md);
}

.filter-tab {
  flex: 1;
  background: none;
  border: none;
  padding: 8px 12px;
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--color-text-muted);
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: all var(--transition-fast);
  min-height: 36px;
}

.filter-tab:hover {
  color: var(--color-text-main);
}

.filter-tab.active {
  background-color: var(--color-surface);
  color: var(--color-primary);
  box-shadow: var(--shadow-sm);
}

/* ==========================================================================
   Book List & Cards
   ========================================================================== */
.book-list {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.book-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 16px;
  box-shadow: var(--shadow-sm);
  transition: transform var(--transition-fast), box-shadow var(--transition-fast), border-color var(--transition-fast);
  display: flex;
  flex-direction: column;
  gap: 12px;
  position: relative;
}

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

.book-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 12px;
}

.book-info {
  flex: 1;
  min-width: 0; /* Ensures word wrap works properly */
}

.book-title {
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--color-text-main);
  word-break: break-word;
  line-height: 1.35;
  margin-bottom: 4px;
}

.book-author {
  font-size: 0.9rem;
  color: var(--color-text-muted);
  display: flex;
  align-items: center;
  gap: 4px;
  word-break: break-word;
}

/* Book Card Rating Display */
.book-rating-display {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  margin-top: 6px;
  background: #f8fafc;
  padding: 3px 8px;
  border-radius: var(--radius-sm);
  border: 1px solid #f1f5f9;
  width: fit-content;
}

.stars-display {
  display: inline-flex;
  gap: 2px;
  line-height: 1;
}

.star-icon {
  font-size: 0.95rem;
  line-height: 1;
}

.star-icon.filled {
  color: #f59e0b;
}

.star-icon.empty {
  color: #e2e8f0;
}

.rating-score-text {
  font-size: 0.775rem;
  font-weight: 600;
  color: var(--color-text-muted);
}

.book-rating-display.unrated .rating-score-text {
  color: var(--color-text-light);
  font-style: italic;
  font-weight: normal;
}

/* Status Badge */
.status-badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 10px;
  border-radius: var(--radius-full);
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.02em;
  white-space: nowrap;
  flex-shrink: 0;
}

.status-badge::before {
  content: "";
  display: inline-block;
  width: 6px;
  height: 6px;
  border-radius: 50%;
}

.status-badge.read {
  background-color: var(--color-read-bg);
  color: var(--color-read-text);
  border: 1px solid var(--color-read-border);
}

.status-badge.read::before {
  background-color: #10b981;
}

.status-badge.unread {
  background-color: var(--color-unread-bg);
  color: var(--color-unread-text);
  border: 1px solid var(--color-unread-border);
}

.status-badge.unread::before {
  background-color: #f59e0b;
}

/* Book Card Actions */
.book-actions {
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-top: 1px solid #f1f5f9;
  padding-top: 12px;
  gap: 8px;
  flex-wrap: wrap;
}

.btn-toggle-read {
  background: none;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  padding: 6px 12px;
  font-size: 0.8rem;
  font-weight: 500;
  color: var(--color-text-main);
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: 6px;
  transition: all var(--transition-fast);
  min-height: 36px;
}

.btn-toggle-read:hover {
  background-color: var(--color-bg);
  border-color: var(--color-border-hover);
}

.action-buttons-group {
  display: flex;
  align-items: center;
  gap: 6px;
  margin-left: auto;
}

.btn-icon-action {
  background: none;
  border: 1px solid transparent;
  border-radius: var(--radius-sm);
  padding: 6px 10px;
  font-size: 0.825rem;
  font-weight: 500;
  color: var(--color-text-muted);
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: 4px;
  transition: all var(--transition-fast);
  min-height: 36px;
}

.btn-icon-action:hover {
  background-color: var(--color-bg);
  color: var(--color-text-main);
  border-color: var(--color-border);
}

.btn-icon-action.delete-action:hover {
  background-color: var(--color-danger-subtle);
  color: var(--color-danger);
  border-color: #fecaca;
}

/* ==========================================================================
   Friendly Empty State
   ========================================================================== */
.empty-state {
  text-align: center;
  padding: 48px 20px;
  background: var(--color-surface);
  border: 2px dashed var(--color-border);
  border-radius: var(--radius-lg);
  margin: 10px 0;
}

.empty-icon {
  width: 72px;
  height: 72px;
  background-color: var(--color-primary-subtle);
  color: var(--color-primary);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 16px;
}

.empty-title {
  font-size: 1.15rem;
  font-weight: 600;
  color: var(--color-text-main);
  margin-bottom: 6px;
}

.empty-description {
  font-size: 0.9rem;
  color: var(--color-text-muted);
  max-width: 320px;
  margin: 0 auto 16px;
}

/* ==========================================================================
   Modals
   ========================================================================== */
.modal-backdrop {
  position: fixed;
  inset: 0;
  background-color: rgba(15, 23, 42, 0.55);
  backdrop-filter: blur(3px);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 16px;
  z-index: 1000;
  opacity: 0;
  pointer-events: none;
  transition: opacity var(--transition-normal);
}

.modal-backdrop.active {
  opacity: 1;
  pointer-events: auto;
}

.modal-card {
  background: var(--color-surface);
  border-radius: var(--radius-lg);
  width: 100%;
  max-width: 440px;
  padding: 24px;
  box-shadow: var(--shadow-lg);
  transform: translateY(10px) scale(0.97);
  transition: transform var(--transition-normal);
}

.modal-backdrop.active .modal-card {
  transform: translateY(0) scale(1);
}

.modal-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 20px;
}

.modal-title {
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--color-text-main);
}

.modal-close-btn {
  background: none;
  border: none;
  font-size: 1.5rem;
  line-height: 1;
  color: var(--color-text-muted);
  cursor: pointer;
  padding: 4px;
  border-radius: var(--radius-sm);
}

.modal-close-btn:hover {
  color: var(--color-text-main);
}

.modal-actions {
  display: flex;
  gap: 10px;
  justify-content: flex-end;
  margin-top: 24px;
}

.modal-actions .btn {
  flex: 1;
}

/* Delete Specific Modal */
.delete-card {
  text-align: center;
}

.delete-icon {
  width: 52px;
  height: 52px;
  background-color: var(--color-danger-subtle);
  color: var(--color-danger);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 16px;
}

.delete-message {
  font-size: 0.95rem;
  color: var(--color-text-muted);
  margin-bottom: 16px;
  line-height: 1.45;
  word-break: break-word;
}

/* ==========================================================================
   Footer
   ========================================================================== */
.app-footer {
  text-align: center;
  margin-top: 36px;
  font-size: 0.8rem;
  color: var(--color-text-light);
}

/* ==========================================================================
   Mobile Responsive Tweaks
   ========================================================================== */
@media (max-width: 480px) {
  body {
    padding: 12px 10px;
  }

  .card {
    padding: 16px;
  }

  .brand-title {
    font-size: 1.35rem;
  }

  .stat-number {
    font-size: 1.3rem;
  }

  .book-actions {
    flex-direction: column;
    align-items: stretch;
  }

  .action-buttons-group {
    margin-left: 0;
    justify-content: space-between;
  }

  .btn-icon-action {
    flex: 1;
    justify-content: center;
  }

  .modal-card {
    padding: 20px;
  }
}