/*
  English comments: Main stylesheet for the site
  - Google Fonts are included in each HTML <head>. Change font families here if you want different fonts.
  - Light/dark theme variables are defined below. Change colors here.
  - Logo located in /images/logo.svg; fallback cover in /images/fallback-cover.svg
*/
:root {
  --font-sans: 'Inter', system-ui, -apple-system, 'Segoe UI', Roboto, 'Helvetica Neue', Arial;
  --font-serif: 'Libre Baskerville', Georgia, 'Times New Roman', serif;
  --bg: #ffffff;
  --text: #0b0b0b;
  --muted: #6b6b6b;
  --accent: #6b5cFF;
  --card-bg: #fbfbfb;
  --focus: #2b6df6;
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.08);
  --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.1);
  --shadow-lg: 0 8px 24px rgba(0, 0, 0, 0.12);
  --transition-fast: 150ms ease-out;
  --transition-base: 250ms ease-out;
}

/* Prevent flash during maintenance check */
html.checking-maintenance body {
  opacity: 0 !important;
  pointer-events: none;
}

.dark {
  --bg: #0b0b10;
  --text: #e6e6e6;
  --muted: #9aa0a6;
  --accent: #8b7dff;
  --card-bg: #0f1013;
  --focus: #7aa2ff;
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.3);
  --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.4);
  --shadow-lg: 0 8px 24px rgba(0, 0, 0, 0.5);
}

/* Respect reduced motion preferences */
@media (prefers-reduced-motion: reduce) {

  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}

* {
  box-sizing: border-box
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: var(--font-sans);
  background: var(--bg);
  color: var(--text);
  line-height: 1.45;
  transition: background var(--transition-base), color var(--transition-base);
  padding-top: 70px;
  /* Spacer for fixed header */
}

/* Headings use a serif for a subtle 'book' vibe */
h1,
h2,
h3,
h4,
h5 {
  font-family: var(--font-serif);
  margin-top: 0;
  line-height: 1.2;
}

h1 {
  font-size: 3rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  margin-bottom: 1rem;
}

h2 {
  font-size: 2.25rem;
  font-weight: 700;
  letter-spacing: -0.01em;
  margin-bottom: 0.75rem;
}

h3 {
  font-size: 1.5rem;
  font-weight: 600;
  margin-bottom: 0.5rem;
}

h4 {
  font-size: 1.25rem;
  font-weight: 600;
}

p {
  font-size: 1rem;
  line-height: 1.6;
  margin-bottom: 1rem;
}

.container {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 1.25rem;
}

/* Header with sticky behavior and animations */
.site-header {
  border-bottom: 1px solid rgba(0, 0, 0, 0.08);
  background: color-mix(in srgb, var(--bg) 85%, transparent);
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  width: 100%;
  z-index: 1000;
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  transition: all var(--transition-base);
}

.dark .site-header {
  border-bottom-color: rgba(255, 255, 255, 0.1);
}

.header-inner {
  display: flex;
  align-items: center;
  gap: 1rem;
  padding: 0.75rem 0
}

.logo-img {
  height: 36px;
  transition: transform var(--transition-fast);
}

.logo:hover .logo-img {
  transform: scale(1.05);
}

/* Mobile hamburger menu */
.menu-toggle {
  display: none;
  background: transparent;
  border: none;
  cursor: pointer;
  padding: 0;
  margin-left: auto;
  color: var(--text);
  width: 44px;
  height: 44px;
  position: relative;
  z-index: 101;
  display: none;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  gap: 5px;
}

.burger-bar {
  display: block;
  width: 22px;
  height: 2px;
  background-color: currentColor;
  border-radius: 2px;
  transition: transform var(--transition-base), opacity var(--transition-base);
}

.menu-toggle[aria-expanded="true"] .burger-bar:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}

.menu-toggle[aria-expanded="true"] .burger-bar:nth-child(2) {
  opacity: 0;
}

.menu-toggle[aria-expanded="true"] .burger-bar:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

.main-nav {
  display: flex;
  gap: 1rem;
  align-items: center;
}

.main-nav a {
  color: var(--text);
  text-decoration: none;
  padding: 0.5rem 0.75rem;
  border-radius: 6px;
  transition: all var(--transition-fast);
  position: relative;
}

.main-nav a::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 50%;
  transform: translateX(-50%) scaleX(0);
  width: 80%;
  height: 2px;
  background: var(--accent);
  transition: transform var(--transition-base);
}

.main-nav a:hover {
  background: rgba(0, 0, 0, 0.04);
}

.dark .main-nav a:hover {
  background: rgba(255, 255, 255, 0.08);
}

.main-nav a[aria-current] {
  font-weight: 600;
}

.main-nav a[aria-current]::after {
  transform: translateX(-50%) scaleX(1);
}

.actions {
  margin-left: auto
}

.btn {
  background: transparent;
  border: 1px solid rgba(0, 0, 0, 0.12);
  padding: 0.75rem 1.25rem;
  min-height: 44px;
  border-radius: 8px;
  cursor: pointer;
  font-family: var(--font-sans);
  font-size: 0.95rem;
  transition: all var(--transition-fast);
  font-weight: 500;
  text-decoration: none;
  display: inline-block;
}

.btn:hover {
  background: rgba(0, 0, 0, 0.04);
  transform: translateY(-1px);
  box-shadow: var(--shadow-sm);
}

.dark .btn {
  border-color: rgba(255, 255, 255, 0.2);
}

.dark .btn:hover {
  background: rgba(255, 255, 255, 0.08);
}

.btn.primary {
  background: var(--accent);
  color: white;
  border: none;
  box-shadow: var(--shadow-sm);
}

.btn.primary:hover {
  background: color-mix(in srgb, var(--accent) 90%, black);
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
}

.btn:active {
  transform: translateY(0);
}

/* Main content with fade-in animation */
.main-content {
  padding-top: 1.5rem;
  padding-bottom: 1.5rem;
  animation: fadeIn 0.5s ease-out;
}

@keyframes fadeIn {
  from {
    opacity: 0;
    transform: translateY(10px);
  }

  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.lead {
  color: var(--muted);
  font-size: 1.1rem;
  margin-bottom: 2rem;
}

/* Grid with stagger animation */
.grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
  gap: 1.25rem;
}

/* Enhanced card design with hover effects */
.card {
  background: var(--card-bg);
  border-radius: 12px;
  overflow: hidden;
  border: 1px solid rgba(0, 0, 0, 0.06);
  transition: all var(--transition-base);
  box-shadow: var(--shadow-sm);
  animation: slideUp 0.4s ease-out backwards;
}

.dark .card {
  border-color: rgba(255, 255, 255, 0.08);
}

/* Stagger animation for cards */
.card:nth-child(1) {
  animation-delay: 0.05s;
}

.card:nth-child(2) {
  animation-delay: 0.1s;
}

.card:nth-child(3) {
  animation-delay: 0.15s;
}

.card:nth-child(4) {
  animation-delay: 0.2s;
}

.card:nth-child(5) {
  animation-delay: 0.25s;
}

.card:nth-child(6) {
  animation-delay: 0.3s;
}

@keyframes slideUp {
  from {
    opacity: 0;
    transform: translateY(20px);
  }

  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-lg);
  border-color: var(--accent);
}

.card-link {
  display: flex;
  flex-direction: column;
  color: inherit;
  text-decoration: none;
  height: 100%;
}

.card-cover {
  width: 100%;
  height: 320px;
  object-fit: cover;
  transition: transform var(--transition-base);
}

.card:hover .card-cover {
  transform: scale(1.05);
}

.card-body {
  padding: 1rem;
  flex-grow: 1;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.card-title {
  font-size: 1.05rem;
  margin: 0;
  line-height: 1.3;
  font-weight: 600;
}

.muted {
  color: var(--muted)
}

.small {
  font-size: 0.85rem;
  line-height: 1.4
}

.chip {
  background: rgba(0, 0, 0, 0.08);
  padding: 0.2rem 0.5rem;
  border-radius: 12px;
  font-size: 0.8rem;
  display: inline-block;
  transition: all var(--transition-fast);
}

.dark .chip {
  background: rgba(255, 255, 255, 0.12);
}

.card:hover .chip {
  background: var(--accent);
  color: white;
}

.actions-row {
  margin-top: 1.5rem;
  text-align: center
}

.actions-row.small {
  margin-top: 0.75rem
}

/* Filters section */
.list-section .filters-grid {
  display: grid;
  grid-template-columns: 1fr 240px;
  gap: 1rem;
  align-items: start;
  margin-bottom: 1.5rem;
}

.quick-filters {
  display: flex;
  gap: 0.5rem;
  align-items: center;
  flex-wrap: wrap;
  margin-bottom: 1rem;
  padding: 1rem;
  background: var(--card-bg);
  border-radius: 8px;
}

.quick-filters label {
  font-weight: 600;
  margin-right: 0.5rem;
}

.quick-filter-btn {
  padding: 0.5rem 1rem;
  min-height: 40px;
  font-size: 0.9rem;
}

.quick-filter-btn.active {
  background: var(--accent);
  color: white;
  border-color: var(--accent);
}

.search-group input {
  width: 100%;
  padding: 0.6rem 0.8rem;
  border-radius: 8px;
  border: 1px solid rgba(0, 0, 0, 0.12);
  font-family: var(--font-sans);
  font-size: 1rem;
  transition: all var(--transition-fast);
}

.search-group input:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px color-mix(in srgb, var(--accent) 15%, transparent);
}

.selects select,
.dates input,
.sort-row select {
  width: 100%;
  padding: 0.5rem;
  border-radius: 8px;
  border: 1px solid rgba(0, 0, 0, 0.12);
  background: var(--card-bg);
  font-family: var(--font-sans);
  transition: all var(--transition-fast);
}

.selects select:focus,
.dates input:focus,
.sort-row select:focus {
  border-color: var(--accent);
  outline: none;
}

.selects {
  display: grid;
  gap: 0.5rem
}

.dates {
  display: flex;
  flex-direction: column;
  gap: 0.5rem
}

.date-row {
  display: flex;
  gap: 0.5rem;
  align-items: center
}

.results-header {
  margin: 1rem 0 0.5rem
}

/* Book detail page */
.book-detail {
  display: grid;
  grid-template-columns: 320px 1fr;
  gap: 2rem;
  align-items: start;
}

.book-cover {
  width: 100%;
  height: auto;
  max-height: 520px;
  object-fit: cover;
  border-radius: 12px;
  box-shadow: var(--shadow-md);
}

.meta {
  padding: 0.5rem 0
}

.buy-buttons {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-top: 1rem;
}

.buy-buttons a {
  padding: 0.6rem 1rem;
  border-radius: 8px;
  background: var(--accent);
  color: white;
  text-decoration: none;
  transition: all var(--transition-fast);
  font-weight: 500;
}

.buy-buttons a:hover {
  background: color-mix(in srgb, var(--accent) 90%, black);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

/* Related books section */
.related-section {
  margin-top: 3rem;
  padding-top: 2rem;
  border-top: 1px solid rgba(0, 0, 0, 0.08);
}

.dark .related-section {
  border-top-color: rgba(255, 255, 255, 0.1);
}

/* FAQ details */
.faq-list details {
  margin: 0.75rem 0;
  padding: 1rem;
  background: var(--card-bg);
  border-radius: 8px;
  border: 1px solid rgba(0, 0, 0, 0.06);
  transition: all var(--transition-fast);
}

.faq-list details:hover {
  box-shadow: var(--shadow-sm);
}

.faq-list summary {
  cursor: pointer;
  font-weight: 600;
  padding: 0.25rem 0;
  transition: color var(--transition-fast);
}

.faq-list summary:hover {
  color: var(--accent);
}

.faq-list details[open] summary {
  margin-bottom: 0.75rem;
  color: var(--accent);
}

/* Empty states */
.empty-state {
  text-align: center;
  padding: 3rem 1rem;
  color: var(--muted);
}

.empty-state-icon {
  font-size: 4rem;
  margin-bottom: 1rem;
  opacity: 0.5;
}

.empty-state h3 {
  color: var(--text);
  margin-bottom: 0.5rem;
}

.site-footer {
  border-top: 1px solid rgba(0, 0, 0, 0.06);
  padding: 2rem 0;
  margin-top: 3rem;
  color: var(--muted);
}

.dark .site-footer {
  border-top-color: rgba(255, 255, 255, 0.1);
}

/* Focus styles */
:focus:not(:focus-visible) {
  outline: none
}

:focus-visible {
  outline: 3px solid var(--focus);
  outline-offset: 3px;
  border-radius: 6px;
}

.main-nav a:focus-visible {
  box-shadow: 0 0 0 3px color-mix(in srgb, var(--focus) 22%, transparent);
  border-radius: 4px;
}

/* Pagination */
.pagination {
  display: flex;
  gap: 0.5rem;
  grid-template-columns: 1fr 240px;
  gap: 1rem;
  align-items: start;
  margin-bottom: 1.5rem;
}

.search-group input {
  width: 100%;
  padding: 0.6rem 0.8rem;
  border-radius: 8px;
  border: 1px solid rgba(0, 0, 0, 0.12);
  font-family: var(--font-sans);
  font-size: 1rem;
  transition: all var(--transition-fast);
}

.search-group input:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px color-mix(in srgb, var(--accent) 15%, transparent);
}

.selects select,
.dates input,
.sort-row select {
  width: 100%;
  padding: 0.5rem;
  border-radius: 8px;
  border: 1px solid rgba(0, 0, 0, 0.12);
  background: var(--card-bg);
  font-family: var(--font-sans);
  transition: all var(--transition-fast);
}

.selects select:focus,
.dates input:focus,
.sort-row select:focus {
  border-color: var(--accent);
  outline: none;
}

.selects {
  display: grid;
  gap: 0.5rem
}

.dates {
  display: flex;
  flex-direction: column;
  gap: 0.5rem
}

.date-row {
  display: flex;
  gap: 0.5rem;
  align-items: center
}

.results-header {
  margin: 1rem 0 0.5rem
}

/* Book detail page */
.book-detail {
  display: grid;
  grid-template-columns: 320px 1fr;
  gap: 2rem;
  align-items: start;
}

.book-cover {
  width: 100%;
  height: auto;
  max-height: 520px;
  object-fit: cover;
  border-radius: 12px;
  box-shadow: var(--shadow-md);
}

.meta {
  padding: 0.5rem 0
}

.buy-buttons {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-top: 1rem;
}

.buy-buttons a {
  padding: 0.6rem 1rem;
  border-radius: 8px;
  background: var(--accent);
  color: white;
  text-decoration: none;
  transition: all var(--transition-fast);
  font-weight: 500;
}

.buy-buttons a:hover {
  background: color-mix(in srgb, var(--accent) 90%, black);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

/* Related books section */
.related-section {
  margin-top: 3rem;
  padding-top: 2rem;
  border-top: 1px solid rgba(0, 0, 0, 0.08);
}

.dark .related-section {
  border-top-color: rgba(255, 255, 255, 0.1);
}

/* FAQ details */
.faq-list details {
  margin: 0.75rem 0;
  padding: 1rem;
  background: var(--card-bg);
  border-radius: 8px;
  border: 1px solid rgba(0, 0, 0, 0.06);
  transition: all var(--transition-fast);
}

.faq-list details:hover {
  box-shadow: var(--shadow-sm);
}

.faq-list summary {
  cursor: pointer;
  font-weight: 600;
  padding: 0.25rem 0;
  transition: color var(--transition-fast);
}

.faq-list summary:hover {
  color: var(--accent);
}

.faq-list details[open] summary {
  margin-bottom: 0.75rem;
  color: var(--accent);
}

/* Empty states */
.empty-state {
  text-align: center;
  padding: 3rem 1rem;
  color: var(--muted);
}

.empty-state-icon {
  font-size: 4rem;
  margin-bottom: 1rem;
  opacity: 0.5;
}

.empty-state h3 {
  color: var(--text);
  margin-bottom: 0.5rem;
}

.site-footer {
  border-top: 1px solid rgba(0, 0, 0, 0.06);
  padding: 2rem 0;
  margin-top: 3rem;
  color: var(--muted);
}

.dark .site-footer {
  border-top-color: rgba(255, 255, 255, 0.1);
}

/* Focus styles */
:focus:not(:focus-visible) {
  outline: none
}

:focus-visible {
  outline: 3px solid var(--focus);
  outline-offset: 3px;
  border-radius: 6px;
}

.main-nav a:focus-visible {
  box-shadow: 0 0 0 3px color-mix(in srgb, var(--focus) 22%, transparent);
  border-radius: 4px;
}

/* Pagination */
.pagination {
  display: flex;
  gap: 0.5rem;
  justify-content: center;
  margin-top: 2rem;
  flex-wrap: wrap;
}

.error {
  color: #d32f2f;
  background: rgba(211, 47, 47, 0.1);
  padding: 1rem;
  border-radius: 8px;
  border-left: 4px solid #d32f2f;
}

/* Improve contrast slightly for muted text */
.muted {
  color: color-mix(in srgb, var(--text) 60%, transparent)
}

/* Mobile responsive */
@media (max-width:800px) {
  h1 {
    font-size: 2rem
  }

  h2 {
    font-size: 1.5rem
  }

  .header-inner {
    position: relative;
  }

  .menu-toggle {
    display: flex
  }

  .main-nav {
    position: fixed;
    top: 64px;
    left: 0;
    right: 0;
    background: var(--bg);
    flex-direction: column;
    padding: 1rem;
    box-shadow: var(--shadow-lg);
    transform: translateY(-100%);
    opacity: 0;
    pointer-events: none;
    transition: all var(--transition-base);
    gap: 0;
    z-index: 999;
  }

  .main-nav.active {
    transform: translateY(0);
    opacity: 1;
    pointer-events: all;
  }

  .main-nav a {
    width: 100%;
    padding: 0.75rem 1rem;
    border-radius: 6px;
  }

  .main-nav a::after {
    display: none
  }

  .actions {
    position: fixed;
    top: 64px;
    left: 0;
    right: 0;
    background: var(--bg);
    padding: 0 1rem 1rem;
    margin: 0;
    box-shadow: var(--shadow-lg);
    transform: translateY(-100%);
    opacity: 0;
    pointer-events: none;
    transition: all var(--transition-base);
    z-index: 998;
  }

  .main-nav.active~.menu-toggle~.actions {
    transform: translateY(200px);
    opacity: 1;
    pointer-events: all;
  }

  .actions .btn {
    width: 100%;
    font-size: 1.5rem;
    padding: 0.5rem;
  }

  .book-detail {
    grid-template-columns: 1fr;
    gap: 1.5rem
  }

  .card-cover {
    height: 220px
  }

  .list-section .filters-grid {
    grid-template-columns: 1fr
  }

  .grid {
    grid-template-columns: repeat(auto-fill, minmax(160px, 1fr));
    gap: 1rem
  }
}

/* Dark mode tweaks */
.dark {
  --card-bg: #0f1114;
  --muted: #9aa0a6
}

/* Statistics */
.stats-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 1.5rem;
  margin-bottom: 3rem;
  margin-top: 2rem;
}

.stat-card {
  background: var(--card-bg);
  padding: 1.5rem;
  border-radius: 12px;
  border: 1px solid rgba(0, 0, 0, 0.06);
  text-align: center;
  transition: transform var(--transition-fast), box-shadow var(--transition-fast);
  animation: slideUp 0.4s ease-out;
}

.stat-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
}

.stat-value {
  display: block;
  font-size: 1.75rem;
  font-weight: 800;
  color: var(--accent);
  margin-bottom: 0.25rem;
}

.stat-label {
  font-size: 0.9rem;
  color: var(--muted);
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.dark .stat-card {
  border-color: rgba(255, 255, 255, 0.1);
}

.back-button-container {
  margin-bottom: 2rem;
}

/* Contact Page Refined */
.contact-section {
  max-width: 600px;
  margin: 3rem auto;
  padding: 2.5rem;
  background: var(--card-bg);
  border-radius: 16px;
  border: 1px solid rgba(0, 0, 0, 0.06);
  box-shadow: var(--shadow-md);
  animation: slideUp 0.5s ease-out;
}

.dark .contact-section {
  border-color: rgba(255, 255, 255, 0.1);
}

.contact-section h1 {
  text-align: center;
  margin-bottom: 0.5rem;
}

.contact-section p {
  text-align: center;
  color: var(--muted);
  margin-bottom: 2rem;
}

#contact-form {
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}

#contact-form label {
  font-weight: 600;
  font-size: 0.95rem;
  margin-bottom: -0.75rem;
  color: var(--text);
}

#contact-form input,
#contact-form textarea {
  width: 100%;
  padding: 0.8rem 1rem;
  border-radius: 10px;
  border: 1px solid rgba(0, 0, 0, 0.12);
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-sans);
  font-size: 1rem;
  transition: all var(--transition-fast);
}

#contact-form input:focus,
#contact-form textarea:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 4px color-mix(in srgb, var(--accent) 15%, transparent);
}

.dark #contact-form input,
.dark #contact-form textarea {
  border-color: rgba(255, 255, 255, 0.12);
}

.form-actions {
  margin-top: 1rem;
}

#contact-form .btn.primary {
  width: 100%;
  padding: 1rem;
  font-size: 1.1rem;
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 0.5rem;
}

#form-message {
  text-align: center;
  margin-top: 1rem;
  font-weight: 500;
  min-height: 1.5rem;
}

#form-message.success {
  color: #10b981;
}

#form-message.error {
  color: #ef4444;
}