/* ================================================
   To Be Read - Literary Design System
   ================================================ */

/* CSS Custom Properties */
:root {
  /* Colors - Minimal palette, book covers provide color */
  --color-primary: #2c2c2c;
  --color-primary-hover: #000000;
  --color-danger: #8b0000;
  --color-danger-hover: #660000;
  --color-success: #2d5016;

  --color-bg: #ffffff;
  --color-surface: #fafafa;
  --color-text: #1a1a1a;
  --color-text-muted: #666666;
  --color-border: #e0e0e0;
  --color-border-focus: #2c2c2c;

  /* Spacing - Generous for editorial feel */
  --space-xs: 0.375rem;
  --space-sm: 0.625rem;
  --space-md: 1.125rem;
  --space-lg: 1.875rem;
  --space-xl: 2.5rem;
  --space-2xl: 3.75rem;
  --space-3xl: 5rem;

  /* Typography - Serif for literary aesthetic */
  --font-serif: 'Iowan Old Style', 'Palatino Linotype', 'URW Palladio L', P052, serif;
  --font-sans: 'Helvetica Neue', Helvetica, Arial, sans-serif;
  --font-size-sm: 0.8125rem;
  --font-size-base: 0.9375rem;
  --font-size-lg: 1.0625rem;
  --font-size-xl: 1.375rem;
  --font-size-2xl: 1.875rem;
  --font-size-3xl: 2.5rem;
  --font-size-4xl: 3.25rem;

  /* Line heights for readability */
  --line-tight: 1.2;
  --line-normal: 1.5;
  --line-relaxed: 1.7;

  /* Borders - Subtle */
  --radius-sm: 2px;
  --radius-md: 3px;
  --radius-lg: 4px;

  /* Shadows - Minimal, paper-like */
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.06);
  --shadow-md: 0 2px 8px rgba(0, 0, 0, 0.08);
  --shadow-lg: 0 4px 16px rgba(0, 0, 0, 0.1);
  --shadow-book: 2px 4px 12px rgba(0, 0, 0, 0.15);

  /* Transitions */
  --transition-fast: 180ms cubic-bezier(0.4, 0, 0.2, 1);
  --transition-base: 250ms cubic-bezier(0.4, 0, 0.2, 1);
}

/* ================================================
   Reset & Base Styles
   ================================================ */
*,
*::before,
*::after {
  box-sizing: border-box;
}

* {
  margin: 0;
  padding: 0;
}

html {
  font-size: 16px;
  -webkit-text-size-adjust: 100%;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: var(--font-serif);
  font-size: var(--font-size-base);
  line-height: var(--line-relaxed);
  color: var(--color-text);
  background-color: var(--color-bg);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

img {
  max-width: 100%;
  height: auto;
  display: block;
}

a {
  color: var(--color-text);
  text-decoration: underline;
  text-decoration-thickness: 1px;
  text-underline-offset: 2px;
  transition: color var(--transition-fast);
}

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

a:focus-visible {
  outline: 2px solid var(--color-border-focus);
  outline-offset: 3px;
}

ul {
  list-style: none;
}

/* Headings use serif with italics */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-serif);
  font-weight: 400;
  font-style: italic;
  line-height: var(--line-tight);
  letter-spacing: -0.01em;
}

/* ================================================
   Accessibility
   ================================================ */
.skip-link {
  position: absolute;
  top: -100%;
  left: var(--space-md);
  padding: var(--space-sm) var(--space-md);
  background: var(--color-primary);
  color: white;
  border-radius: var(--radius-md);
  z-index: 100;
  transition: top var(--transition-fast);
}

.skip-link:focus {
  top: var(--space-md);
}

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

/* Focus styles for keyboard navigation */
:focus-visible {
  outline: 2px solid var(--color-border-focus);
  outline-offset: 2px;
}

/* Reduced motion */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}

/* Ensure hidden attribute works with flex elements */
[hidden] {
  display: none !important;
}

/* ================================================
   Layout
   ================================================ */
.container {
  width: 100%;
  max-width: 48rem;
  margin: 0 auto;
  padding: 0 var(--space-md);
}

.main {
  flex: 1;
  padding: var(--space-lg) 0 var(--space-2xl);
}

/* ================================================
   Header & Navigation
   ================================================ */
.header {
  background: var(--color-bg);
  border-bottom: 1px solid var(--color-border);
  padding: var(--space-md) 0;
  position: sticky;
  top: 0;
  z-index: 50;
  backdrop-filter: blur(8px);
  background: rgba(255, 255, 255, 0.95);
}

.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-md);
}

.nav-brand {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  font-family: var(--font-serif);
  font-size: var(--font-size-xl);
  font-style: italic;
  font-weight: 400;
  color: var(--color-text);
  text-decoration: none;
  letter-spacing: -0.01em;
}

.nav-brand:hover {
  color: var(--color-primary-hover);
  text-decoration: none;
}

.nav-icon {
  flex-shrink: 0;
  opacity: 0.8;
}

.nav-add .btn-text {
  display: none;
}

@media (min-width: 480px) {
  .nav-add .btn-text {
    display: inline;
  }
}

/* ================================================
   Footer
   ================================================ */
.footer {
  background: var(--color-bg);
  border-top: 1px solid var(--color-border);
  padding: var(--space-xl) 0;
  text-align: center;
  color: var(--color-text-muted);
  font-size: var(--font-size-sm);
  font-family: var(--font-sans);
  margin-top: var(--space-3xl);
}

/* ================================================
   Buttons
   ================================================ */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-sm);
  padding: var(--space-sm) var(--space-lg);
  font-family: var(--font-sans);
  font-size: var(--font-size-sm);
  font-weight: 500;
  line-height: 1.5;
  letter-spacing: 0.02em;
  text-transform: uppercase;
  border: 1px solid transparent;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: all var(--transition-fast);
  text-decoration: none;
  white-space: nowrap;
  min-width: 0;
}

.btn:focus-visible {
  outline: 2px solid var(--color-border-focus);
  outline-offset: 3px;
}

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

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

.btn-primary:hover:not(:disabled) {
  background: var(--color-primary-hover);
  border-color: var(--color-primary-hover);
  text-decoration: none;
  transform: translateY(-1px);
  box-shadow: var(--shadow-sm);
}

.btn-secondary {
  background: transparent;
  color: var(--color-text);
  border: 1px solid var(--color-border);
}

.btn-secondary:hover:not(:disabled) {
  background: var(--color-surface);
  text-decoration: none;
  transform: translateY(-1px);
}

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

.btn-danger:hover:not(:disabled) {
  background: var(--color-danger-hover);
  border-color: var(--color-danger-hover);
  text-decoration: none;
  transform: translateY(-1px);
}

.btn-link {
  background: transparent;
  color: var(--color-text);
  padding: 0;
  border: none;
  text-transform: none;
  font-family: var(--font-serif);
  text-decoration: underline;
  text-underline-offset: 2px;
}

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

.btn-icon {
  padding: var(--space-sm);
  border-radius: var(--radius-sm);
}

.btn-lg {
  padding: var(--space-md) var(--space-xl);
  font-size: var(--font-size-base);
}

/* ================================================
   Page Header
   ================================================ */
.page-header {
  margin-bottom: var(--space-2xl);
  padding-bottom: var(--space-lg);
  border-bottom: 1px solid var(--color-border);
}

.page-title {
  font-size: var(--font-size-3xl);
  font-family: var(--font-serif);
  font-style: italic;
  font-weight: 400;
  margin-bottom: var(--space-sm);
  letter-spacing: -0.02em;
}

.page-subtitle {
  color: var(--color-text-muted);
  font-family: var(--font-sans);
  font-size: var(--font-size-base);
  line-height: var(--line-normal);
}

/* ================================================
   Alerts
   ================================================ */
.alert {
  display: flex;
  align-items: flex-start;
  gap: var(--space-md);
  padding: var(--space-md) var(--space-lg);
  border-radius: var(--radius-sm);
  margin-bottom: var(--space-lg);
  font-family: var(--font-sans);
  font-size: var(--font-size-sm);
  line-height: var(--line-normal);
}

.alert-error {
  background: #fff5f5;
  color: var(--color-danger);
  border: 1px solid var(--color-danger);
  border-left-width: 3px;
}

.alert-success {
  background: #f0fdf4;
  color: var(--color-success);
  border: 1px solid var(--color-success);
  border-left-width: 3px;
}

/* ================================================
   Book List
   ================================================ */
.book-list {
  display: flex;
  flex-direction: column;
  gap: var(--space-xl);
}

.book-card {
  background: var(--color-bg);
  border-bottom: 1px solid var(--color-border);
  padding-bottom: var(--space-xl);
  transition: transform var(--transition-base);
}

.book-card:hover {
  transform: translateX(4px);
}

.book-content {
  display: grid;
  grid-template-columns: 90px 1fr auto;
  gap: var(--space-lg);
  align-items: start;
}

.book-cover-wrap {
  width: 90px;
  flex-shrink: 0;
}

.book-cover {
  width: 100%;
  aspect-ratio: 2/3;
  object-fit: cover;
  border-radius: var(--radius-sm);
  background: var(--color-surface);
  box-shadow: var(--shadow-book);
  transition: transform var(--transition-base);
}

.book-card:hover .book-cover {
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(0, 0, 0, 0.18);
}

.book-cover-placeholder {
  width: 100%;
  aspect-ratio: 2/3;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  color: var(--color-text-muted);
}

.book-cover-placeholder.large {
  aspect-ratio: 2/3;
  max-width: 240px;
}

.book-info {
  min-width: 0;
}

.book-title {
  font-family: var(--font-serif);
  font-size: var(--font-size-xl);
  font-style: italic;
  font-weight: 400;
  margin-bottom: var(--space-xs);
  line-height: var(--line-tight);
  letter-spacing: -0.01em;
}

.book-title a {
  color: inherit;
  text-decoration: none;
}

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

.book-author {
  color: var(--color-text-muted);
  font-family: var(--font-sans);
  font-size: var(--font-size-sm);
  margin-bottom: var(--space-md);
  line-height: var(--line-normal);
}

.book-meta {
  display: flex;
  align-items: center;
  gap: var(--space-xs);
  color: var(--color-text-muted);
  font-family: var(--font-sans);
  font-size: var(--font-size-sm);
  margin-bottom: var(--space-sm);
  line-height: var(--line-normal);
}

.book-meta strong {
  color: var(--color-text);
  font-weight: 500;
}

.book-reason {
  font-family: var(--font-serif);
  font-size: var(--font-size-base);
  color: var(--color-text);
  margin-bottom: var(--space-md);
  line-height: var(--line-relaxed);
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
  font-style: italic;
}

.book-date {
  display: flex;
  align-items: center;
  gap: var(--space-xs);
  font-family: var(--font-sans);
  font-size: var(--font-size-sm);
  color: var(--color-text-muted);
  line-height: var(--line-normal);
}

.book-actions {
  flex-shrink: 0;
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
}

/* ================================================
   Empty State
   ================================================ */
.empty-state {
  text-align: center;
  padding: var(--space-3xl) var(--space-lg);
  margin: var(--space-2xl) 0;
}

.empty-icon {
  color: var(--color-text-muted);
  margin-bottom: var(--space-xl);
  opacity: 0.4;
}

.empty-state h2 {
  font-family: var(--font-serif);
  font-size: var(--font-size-2xl);
  font-style: italic;
  font-weight: 400;
  margin-bottom: var(--space-md);
  letter-spacing: -0.01em;
}

.empty-state p {
  color: var(--color-text-muted);
  font-family: var(--font-sans);
  font-size: var(--font-size-base);
  margin-bottom: var(--space-xl);
  line-height: var(--line-relaxed);
}

/* ================================================
   Search Section
   ================================================ */
.search-section {
  margin-bottom: var(--space-2xl);
}

.section-title {
  font-family: var(--font-serif);
  font-size: var(--font-size-xl);
  font-style: italic;
  font-weight: 400;
  margin-bottom: var(--space-lg);
  letter-spacing: -0.01em;
}

.search-box {
  margin-bottom: var(--space-lg);
}

.search-input-wrap {
  position: relative;
  display: flex;
  align-items: center;
}

.search-icon {
  position: absolute;
  left: var(--space-md);
  color: var(--color-text-muted);
  pointer-events: none;
}

.search-input {
  width: 100%;
  padding: var(--space-md) var(--space-md) var(--space-md) calc(var(--space-md) * 2 + 24px);
  font-family: var(--font-sans);
  font-size: var(--font-size-base);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  background: var(--color-bg);
  color: var(--color-text);
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
  line-height: var(--line-normal);
}

.search-input:focus {
  outline: none;
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px rgba(44, 44, 44, 0.08);
}

.search-spinner {
  position: absolute;
  right: var(--space-md);
  color: var(--color-primary);
  animation: spin 1s linear infinite;
}

@keyframes spin {
  from { transform: rotate(0deg); }
  to { transform: rotate(360deg); }
}

.form-hint {
  font-family: var(--font-sans);
  font-size: var(--font-size-sm);
  color: var(--color-text-muted);
  margin-top: var(--space-sm);
  line-height: var(--line-normal);
}

/* Search Results */
.search-results {
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  max-height: 400px;
  overflow-y: auto;
  box-shadow: var(--shadow-md);
}

.search-result {
  display: flex;
  gap: var(--space-md);
  padding: var(--space-md);
  border-bottom: 1px solid var(--color-border);
  cursor: pointer;
  transition: background var(--transition-fast);
}

.search-result:last-child {
  border-bottom: none;
}

.search-result:hover,
.search-result:focus {
  background: var(--color-surface);
}

.search-result:focus {
  outline: 2px solid var(--color-border-focus);
  outline-offset: -2px;
}

.search-result-cover {
  width: 50px;
  flex-shrink: 0;
}

.search-result-cover img {
  width: 100%;
  aspect-ratio: 2/3;
  object-fit: cover;
  border-radius: var(--radius-sm);
  box-shadow: var(--shadow-sm);
}

.search-result-info {
  min-width: 0;
  flex: 1;
}

.search-result-title {
  font-family: var(--font-serif);
  font-style: italic;
  font-weight: 400;
  font-size: var(--font-size-base);
  margin-bottom: var(--space-xs);
  line-height: var(--line-tight);
}

.search-result-author {
  font-family: var(--font-sans);
  font-size: var(--font-size-sm);
  color: var(--color-text-muted);
  line-height: var(--line-normal);
}

.search-result-year {
  font-family: var(--font-sans);
  font-size: var(--font-size-sm);
  color: var(--color-text-muted);
  line-height: var(--line-normal);
}

.search-no-results {
  padding: var(--space-xl);
  text-align: center;
  color: var(--color-text-muted);
  font-family: var(--font-sans);
  font-size: var(--font-size-sm);
}

.search-result-price {
  font-family: var(--font-sans);
  font-size: var(--font-size-sm);
  font-weight: 600;
  color: var(--color-success);
  margin-top: var(--space-xs);
}

/* ================================================
   Divider
   ================================================ */
.divider {
  display: flex;
  align-items: center;
  gap: var(--space-lg);
  margin: var(--space-2xl) 0;
  color: var(--color-text-muted);
  font-family: var(--font-sans);
  font-size: var(--font-size-sm);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.divider::before,
.divider::after {
  content: '';
  flex: 1;
  height: 1px;
  background: var(--color-border);
}

/* ================================================
   Forms
   ================================================ */
.form-section {
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  padding: var(--space-xl);
}

.book-form {
  display: flex;
  flex-direction: column;
  gap: var(--space-lg);
}

.form-group {
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
}

.form-label {
  font-family: var(--font-sans);
  font-weight: 500;
  font-size: var(--font-size-sm);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--color-text);
}

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

.form-input,
.form-textarea {
  padding: var(--space-md);
  font-family: var(--font-serif);
  font-size: var(--font-size-base);
  line-height: var(--line-relaxed);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  background: var(--color-bg);
  color: var(--color-text);
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

.form-input:focus,
.form-textarea:focus {
  outline: none;
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px rgba(44, 44, 44, 0.08);
}

.form-input::placeholder,
.form-textarea::placeholder {
  color: var(--color-text-muted);
  font-style: italic;
}

.form-textarea {
  resize: vertical;
  min-height: 120px;
}

.form-actions {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-md);
  justify-content: flex-end;
  padding-top: var(--space-lg);
  border-top: 1px solid var(--color-border);
  margin-top: var(--space-md);
}

@media (max-width: 480px) {
  .form-actions {
    flex-direction: column-reverse;
  }
  
  .form-actions .btn {
    width: 100%;
  }
}

/* Selected Book Preview */
.selected-book {
  display: flex;
  gap: var(--space-md);
  padding: var(--space-lg);
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  margin-bottom: var(--space-lg);
}

.selected-book-cover {
  width: 60px;
  flex-shrink: 0;
}

.selected-book-cover img {
  width: 100%;
  aspect-ratio: 2/3;
  object-fit: cover;
  border-radius: var(--radius-sm);
  box-shadow: var(--shadow-sm);
}

.selected-book-info {
  min-width: 0;
}

.selected-book-label {
  font-family: var(--font-sans);
  font-size: var(--font-size-sm);
  color: var(--color-text-muted);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: var(--space-xs);
}

.selected-book-title {
  font-family: var(--font-serif);
  font-style: italic;
  font-weight: 400;
  font-size: var(--font-size-base);
  margin-bottom: var(--space-xs);
  line-height: var(--line-tight);
}

.selected-book-author {
  font-family: var(--font-sans);
  font-size: var(--font-size-sm);
  color: var(--color-text-muted);
  margin-bottom: var(--space-sm);
  line-height: var(--line-normal);
}

/* ================================================
   Book Detail Page
   ================================================ */
.book-detail {
  max-width: 100%;
}

.back-link {
  display: inline-flex;
  align-items: center;
  gap: var(--space-sm);
  margin-bottom: var(--space-xl);
  color: var(--color-text-muted);
  font-family: var(--font-sans);
  font-size: var(--font-size-sm);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  text-decoration: none;
}

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

.book-detail-content {
  display: flex;
  flex-direction: column;
  gap: var(--space-2xl);
}

@media (min-width: 640px) {
  .book-detail-content {
    flex-direction: row;
    gap: var(--space-3xl);
  }
}

.book-detail-cover {
  flex-shrink: 0;
  width: 180px;
  margin: 0 auto;
}

@media (min-width: 640px) {
  .book-detail-cover {
    width: 240px;
    margin: 0;
  }
}

.book-cover-large {
  width: 100%;
  aspect-ratio: 2/3;
  object-fit: cover;
  border-radius: var(--radius-sm);
  box-shadow: var(--shadow-book);
}

.book-detail-info {
  flex: 1;
  min-width: 0;
}

.book-detail-title {
  font-family: var(--font-serif);
  font-size: var(--font-size-3xl);
  font-style: italic;
  font-weight: 400;
  margin-bottom: var(--space-sm);
  line-height: var(--line-tight);
  letter-spacing: -0.02em;
}

.book-detail-author {
  font-family: var(--font-sans);
  font-size: var(--font-size-lg);
  color: var(--color-text-muted);
  margin-bottom: var(--space-2xl);
  line-height: var(--line-normal);
}

.book-detail-section {
  margin-bottom: var(--space-xl);
}

.book-detail-section h2 {
  font-family: var(--font-sans);
  font-size: var(--font-size-sm);
  font-weight: 500;
  font-style: normal;
  color: var(--color-text-muted);
  text-transform: uppercase;
  letter-spacing: 0.1em;
  margin-bottom: var(--space-md);
}

.book-detail-section p {
  font-family: var(--font-serif);
  font-size: var(--font-size-base);
  line-height: var(--line-relaxed);
  color: var(--color-text);
}

.book-detail-recommender {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  font-family: var(--font-sans);
}

.book-detail-actions {
  margin-top: var(--space-2xl);
  padding-top: var(--space-xl);
  border-top: 1px solid var(--color-border);
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-md);
}

.btn-amazon {
  background: #ff9900;
  color: #111;
  border-color: #ff9900;
}

.btn-amazon:hover:not(:disabled) {
  background: #e88b00;
  border-color: #e88b00;
  text-decoration: none;
}

/* ================================================
   Modal
   ================================================ */
.modal {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: transparent;
  padding: var(--space-md);
  border: none;
  max-width: none;
  max-height: none;
}

@media (min-width: 480px) {
  .modal {
    padding: var(--space-lg);
  }
}

.modal[open] {
  display: flex;
  align-items: center;
  justify-content: center;
  animation: fadeIn var(--transition-base);
}

.modal::backdrop {
  background: rgba(0, 0, 0, 0.6);
  backdrop-filter: blur(2px);
}

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

.modal-content {
  background: var(--color-bg);
  padding: var(--space-lg);
  border-radius: var(--radius-sm);
  border: 1px solid var(--color-border);
  max-width: 420px;
  width: 100%;
  box-shadow: var(--shadow-lg);
  max-height: calc(100vh - 2rem);
  overflow-y: auto;
}

@media (min-width: 480px) {
  .modal-content {
    padding: var(--space-2xl);
  }
}

.modal-content h2 {
  font-family: var(--font-serif);
  font-size: var(--font-size-xl);
  font-style: italic;
  font-weight: 400;
  margin-bottom: var(--space-md);
  letter-spacing: -0.01em;
}

.modal-content p {
  color: var(--color-text-muted);
  font-family: var(--font-sans);
  font-size: var(--font-size-base);
  line-height: var(--line-relaxed);
  margin-bottom: var(--space-xl);
}

.modal-actions {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-md);
  justify-content: flex-end;
}

@media (max-width: 480px) {
  .modal-actions {
    flex-direction: column-reverse;
  }
  
  .modal-actions .btn {
    width: 100%;
  }
}

/* ================================================
   Error Page
   ================================================ */
.error-page {
  text-align: center;
  padding: var(--space-3xl) var(--space-lg);
}

.error-icon {
  color: var(--color-text-muted);
  margin-bottom: var(--space-xl);
  opacity: 0.4;
}

.error-page h1 {
  font-family: var(--font-serif);
  font-size: var(--font-size-3xl);
  font-style: italic;
  font-weight: 400;
  margin-bottom: var(--space-md);
  letter-spacing: -0.02em;
}

.error-page p {
  color: var(--color-text-muted);
  font-family: var(--font-sans);
  font-size: var(--font-size-base);
  line-height: var(--line-relaxed);
  margin-bottom: var(--space-xl);
}

/* ================================================
   Responsive Adjustments
   ================================================ */
@media (min-width: 640px) {
  .page-title {
    font-size: var(--font-size-4xl);
  }

  .book-content {
    grid-template-columns: 120px 1fr auto;
    gap: var(--space-xl);
  }

  .book-cover-wrap {
    width: 120px;
  }

  .form-actions {
    flex-direction: row;
  }

  .form-section {
    padding: var(--space-2xl);
  }
}

/* ================================================
   Auth Pages
   ================================================ */
.auth-body {
  background: var(--color-bg);
}

.auth-main {
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: var(--space-xl);
  min-height: 100vh;
}

.auth-container {
  width: 100%;
  max-width: 420px;
}

.auth-brand {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-sm);
  font-family: var(--font-serif);
  font-size: var(--font-size-2xl);
  font-style: italic;
  font-weight: 400;
  color: var(--color-text);
  margin-bottom: var(--space-2xl);
  text-decoration: none;
  letter-spacing: -0.01em;
}

.auth-brand:hover {
  color: var(--color-primary-hover);
}

.auth-card {
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  padding: var(--space-2xl);
}

.auth-title {
  font-family: var(--font-serif);
  font-size: var(--font-size-2xl);
  font-style: italic;
  font-weight: 400;
  text-align: center;
  margin-bottom: var(--space-sm);
  letter-spacing: -0.01em;
}

.auth-subtitle {
  text-align: center;
  color: var(--color-text-muted);
  font-family: var(--font-sans);
  font-size: var(--font-size-base);
  line-height: var(--line-normal);
  margin-bottom: var(--space-2xl);
}

.auth-form {
  display: flex;
  flex-direction: column;
  gap: var(--space-lg);
}

.auth-links {
  text-align: center;
  margin-top: var(--space-lg);
  font-family: var(--font-sans);
}

.auth-links a {
  font-size: var(--font-size-sm);
}

.auth-divider {
  display: flex;
  align-items: center;
  gap: var(--space-lg);
  margin: var(--space-xl) 0;
  color: var(--color-text-muted);
  font-family: var(--font-sans);
  font-size: var(--font-size-sm);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.auth-divider::before,
.auth-divider::after {
  content: '';
  flex: 1;
  height: 1px;
  background: var(--color-border);
}

.btn-full {
  width: 100%;
}

/* ================================================
   User Menu
   ================================================ */
.nav-actions {
  display: flex;
  align-items: center;
  gap: var(--space-md);
}

.user-menu {
  position: relative;
  display: none;
}

.user-menu-toggle {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  border: none;
  background: transparent;
  color: var(--color-text);
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: background var(--transition-fast);
}

.user-menu-toggle:hover {
  background: var(--color-surface);
}

.user-menu-dropdown {
  position: absolute;
  top: calc(100% + var(--space-sm));
  right: 0;
  min-width: 220px;
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  box-shadow: var(--shadow-lg);
  z-index: 100;
}

.user-menu-email {
  padding: var(--space-md);
  font-family: var(--font-sans);
  font-size: var(--font-size-sm);
  color: var(--color-text-muted);
  word-break: break-all;
  line-height: var(--line-normal);
}

.user-menu-divider {
  border: none;
  border-top: 1px solid var(--color-border);
  margin: 0;
}

.user-menu-item {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  width: 100%;
  padding: var(--space-md);
  font-family: var(--font-sans);
  font-size: var(--font-size-sm);
  color: var(--color-text);
  background: transparent;
  border: none;
  cursor: pointer;
  transition: background var(--transition-fast);
  text-align: left;
}

.user-menu-item:hover {
  background: var(--color-surface);
}

/* ================================================
   Loading States
   ================================================ */
.loading-state {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: var(--space-3xl);
  color: var(--color-text-muted);
}

.spinner-large {
  width: 48px;
  height: 48px;
  border: 2px solid var(--color-border);
  border-top-color: var(--color-primary);
  border-radius: 50%;
  animation: spin 1s linear infinite;
  margin-bottom: var(--space-xl);
}

.spinner {
  animation: spin 1s linear infinite;
}

.loading-state p {
  font-family: var(--font-sans);
  font-size: var(--font-size-sm);
  line-height: var(--line-normal);
}

/* ================================================
   Tab Navigation
   ================================================ */
.tabs {
  display: flex;
  gap: var(--space-xs);
  margin-bottom: var(--space-xl);
  border-bottom: 1px solid var(--color-border);
  padding-bottom: var(--space-xs);
}

.tab {
  display: inline-flex;
  align-items: center;
  gap: var(--space-sm);
  padding: var(--space-sm) var(--space-md);
  font-family: var(--font-sans);
  font-size: var(--font-size-sm);
  font-weight: 500;
  color: var(--color-text-muted);
  background: transparent;
  border: none;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: all var(--transition-fast);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.tab:hover {
  color: var(--color-text);
  background: var(--color-surface);
}

.tab.active {
  color: var(--color-text);
  background: var(--color-surface);
}

.tab-count {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 20px;
  height: 20px;
  padding: 0 var(--space-xs);
  font-size: 0.6875rem;
  font-weight: 600;
  background: var(--color-border);
  color: var(--color-text-muted);
  border-radius: 10px;
}

.tab.active .tab-count {
  background: var(--color-primary);
  color: white;
}

/* ================================================
   Status Banner (Book Detail)
   ================================================ */
.status-banner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-md);
  padding: var(--space-md) var(--space-lg);
  margin-bottom: var(--space-xl);
  border-radius: var(--radius-sm);
  background: var(--color-surface);
  border: 1px solid var(--color-border);
}

.status-banner.status-tbr {
  background: #fafafa;
  border-color: var(--color-border);
}

.status-banner.status-reading {
  background: #fffbeb;
  border-color: #fcd34d;
}

.status-banner.status-read {
  background: #f0fdf4;
  border-color: #86efac;
}

.status-label {
  font-family: var(--font-sans);
  font-size: var(--font-size-sm);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--color-text);
}

/* ================================================
   Rating Components
   ================================================ */
.rating-input {
  display: grid;
  grid-template-columns: repeat(10, 1fr);
  gap: var(--space-xs);
}

@media (max-width: 480px) {
  .rating-input {
    grid-template-columns: repeat(5, 1fr);
    gap: 6px;
  }
}

.rating-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 100%;
  aspect-ratio: 1;
  font-family: var(--font-sans);
  font-size: var(--font-size-sm);
  font-weight: 500;
  color: var(--color-text-muted);
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: all var(--transition-fast);
  flex-shrink: 0;
}

@media (max-width: 480px) {
  .rating-btn {
    font-size: 0.75rem;
  }
}

.rating-btn:hover {
  border-color: var(--color-primary);
  color: var(--color-text);
}

.rating-btn.active {
  background: var(--color-primary);
  border-color: var(--color-primary);
  color: white;
}

.rating-badge {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: var(--space-xs) var(--space-sm);
  font-family: var(--font-sans);
  font-size: var(--font-size-sm);
  font-weight: 600;
  color: var(--color-success);
  background: #f0fdf4;
  border: 1px solid #86efac;
  border-radius: var(--radius-sm);
}

.rating-badge.large {
  padding: var(--space-sm) var(--space-md);
  font-size: var(--font-size-lg);
}

.rating-display {
  margin-bottom: var(--space-md);
}

.book-rating {
  margin-bottom: var(--space-sm);
}

/* ================================================
   Reading Sessions Timeline
   ================================================ */
.sessions-list {
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
}

.session-card {
  display: flex;
  align-items: center;
  padding: var(--space-md);
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
}

.session-dates {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  font-family: var(--font-sans);
  font-size: var(--font-size-sm);
  color: var(--color-text);
}

.session-arrow {
  display: flex;
  align-items: center;
  color: var(--color-text-muted);
}

.session-end.in-progress {
  color: #d97706;
  font-weight: 500;
  font-style: italic;
}

.no-sessions {
  color: var(--color-text-muted);
  font-family: var(--font-sans);
  font-size: var(--font-size-sm);
  font-style: italic;
}

/* ================================================
   Notes Section
   ================================================ */
.notes-list {
  display: flex;
  flex-direction: column;
  gap: var(--space-md);
  margin-bottom: var(--space-lg);
}

.note-card {
  padding: var(--space-md);
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
}

.note-content {
  font-family: var(--font-serif);
  font-size: var(--font-size-base);
  line-height: var(--line-relaxed);
  color: var(--color-text);
  margin-bottom: var(--space-sm);
  white-space: pre-wrap;
}

.note-meta {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-md);
}

.note-date {
  font-family: var(--font-sans);
  font-size: var(--font-size-sm);
  color: var(--color-text-muted);
}

.note-actions {
  display: flex;
  gap: var(--space-sm);
}

.add-note-form {
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
  align-items: flex-end;
}

.add-note-form .form-textarea {
  width: 100%;
}

.edit-note-form {
  margin-top: var(--space-sm);
}

.edit-note-form .form-textarea {
  width: 100%;
  margin-bottom: var(--space-sm);
}

/* ================================================
   Review Section
   ================================================ */
.review-section {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  padding: var(--space-lg);
}

.review-text {
  font-family: var(--font-serif);
  font-size: var(--font-size-base);
  line-height: var(--line-relaxed);
  color: var(--color-text);
  margin-bottom: var(--space-md);
  white-space: pre-wrap;
}

.review-form {
  display: flex;
  flex-direction: column;
  gap: var(--space-lg);
}

/* ================================================
   Button Variants
   ================================================ */
.btn-success {
  background: var(--color-success);
  color: white;
  border-color: var(--color-success);
}

.btn-success:hover:not(:disabled) {
  background: #1e3a0f;
  border-color: #1e3a0f;
  text-decoration: none;
  transform: translateY(-1px);
}

.btn-sm {
  padding: var(--space-xs) var(--space-md);
  font-size: 0.75rem;
}

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

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

/* ================================================
   Form Inline Actions
   ================================================ */
.form-actions-inline {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-sm);
  justify-content: flex-end;
}

@media (max-width: 480px) {
  .form-actions-inline {
    flex-direction: column-reverse;
  }
  
  .form-actions-inline .btn {
    width: 100%;
  }
}

/* ================================================
   Modal Enhancements
   ================================================ */
.modal-subtitle {
  font-family: var(--font-serif);
  font-style: italic;
  font-size: var(--font-size-lg);
  color: var(--color-text);
  margin-bottom: var(--space-lg);
}

.modal-form {
  display: flex;
  flex-direction: column;
  gap: var(--space-lg);
}

.modal-form .form-group {
  margin-bottom: 0;
}

.modal-form .modal-actions {
  margin-top: var(--space-md);
}