/* ==========================================================================
   KNIHOVNÍČEK - CSS Stylesheet
   Chunky, modern, clean mobile-first interface for iPhone and Web.
   Supports Light & Dark themes with simple lightswitch toggle.
   ========================================================================== */

/* --- CSS Variables / Color Themes --- */
:root[data-theme="dark"] {
  --bg-primary: #121212;
  --bg-secondary: #1e1e1e;
  --bg-card: #282828;
  --bg-hover: #333333;
  --text-main: #f5f5f7;
  --text-muted: #a1a1a6;
  --border-color: #38383a;

  --accent-color: #ff4500; /* Red-Orange */
  --accent-hover: #e03d00;
  --accent-text: #ffffff;

  --star-color: #ffb400;
  --danger-color: #ff3b30;
  --success-color: #34c759;

  --shadow-chunky: 0 4px 0 #000000;
  --shadow-modal: 0 10px 30px rgba(0, 0, 0, 0.8);
}

:root[data-theme="light"] {
  --bg-primary: #f2f2f7;
  --bg-secondary: #ffffff;
  --bg-card: #ffffff;
  --bg-hover: #e5e5ea;
  --text-main: #1c1c1e;
  --text-muted: #6c6c70;
  --border-color: #d1d1d6;

  --accent-color: #ff4500; /* Red-Orange */
  --accent-hover: #e03d00;
  --accent-text: #ffffff;

  --star-color: #ffb400;
  --danger-color: #ff3b30;
  --success-color: #34c759;

  --shadow-chunky: 0 4px 0 #b0b0b8;
  --shadow-modal: 0 10px 30px rgba(0, 0, 0, 0.2);
}

/* Base Reset */
* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
  -webkit-tap-highlight-color: transparent;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}

body {
  background-color: var(--bg-primary);
  color: var(--text-main);
  transition: background-color 0.25s ease, color 0.25s ease;
  overflow-x: hidden;
  min-height: 100vh;
  display: flex;
  justify-content: center;
}

/* Vector SVG Icon Styles */
.svg-icon {
  width: 22px;
  height: 22px;
  display: inline-block;
  vertical-align: middle;
  flex-shrink: 0;
}

.svg-hero {
  width: 48px;
  height: 48px;
  display: inline-block;
  color: var(--accent-color);
}

.logo-icon {
  width: 26px;
  height: 26px;
  color: var(--accent-color);
}

/* App Container */
.app-container {
  width: 100%;
  max-width: 500px;
  min-height: 100vh;
  background-color: var(--bg-primary);
  display: flex;
  flex-direction: column;
  position: relative;
  box-shadow: 0 0 40px rgba(0,0,0,0.3);
}

/* --- App Header --- */
.app-header {
  background-color: var(--bg-secondary);
  border-bottom: 3px solid var(--border-color);
  padding: 12px 16px;
  position: sticky;
  top: 0;
  z-index: 100;
}

.header-content {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.header-right {
  display: flex;
  align-items: center;
  gap: 8px;
}

.logo-area {
  display: flex;
  align-items: center;
  gap: 10px;
  cursor: pointer;
}

.app-title {
  font-size: 20px;
  font-weight: 800;
  color: var(--accent-color);
  letter-spacing: -0.5px;
}

.icon-btn {
  background: var(--bg-card);
  border: 2px solid var(--border-color);
  border-radius: 12px;
  font-size: 18px;
  padding: 6px 10px;
  cursor: pointer;
  transition: transform 0.1s ease, background 0.2s ease;
  box-shadow: var(--shadow-chunky);
  display: flex;
  align-items: center;
  justify-content: center;
}

.icon-btn:active {
  transform: translateY(2px);
  box-shadow: none;
}

/* --- Main Screen Manager --- */
.app-main {
  flex: 1;
  display: flex;
  flex-direction: column;
  padding: 16px;
}

.screen {
  display: none;
  flex-direction: column;
  gap: 14px;
  width: 100%;
  animation: fadeIn 0.2s ease-out;
}

.screen.active {
  display: flex;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(6px); }
  to { opacity: 1; transform: translateY(0); }
}

/* Screen Headers */
.screen-header {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 4px;
}

.screen-header h2 {
  font-size: 20px;
  font-weight: 800;
}

/* --- Chunky Buttons & Rectangular Stack --- */
.chunky-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 12px;
  border: 2px solid var(--border-color);
  border-radius: 14px;
  padding: 12px 18px;
  font-size: 15px;
  font-weight: 700;
  cursor: pointer;
  transition: all 0.15s ease;
  box-shadow: var(--shadow-chunky);
  text-decoration: none;
  user-select: none;
}

.chunky-btn:active {
  transform: translateY(3px);
  box-shadow: 0 1px 0 var(--border-color);
}

.primary-btn {
  background-color: var(--accent-color);
  color: var(--accent-text);
  border-color: #c43500;
}

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

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

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

.outline-btn {
  background-color: transparent;
  color: var(--text-main);
  border-color: var(--border-color);
}

.back-btn {
  padding: 8px 14px;
  font-size: 14px;
  background-color: var(--bg-card);
  color: var(--accent-color);
  border-color: var(--accent-color);
  border-width: 2px;
}

.small-btn {
  padding: 8px 12px;
  font-size: 13px;
  border-radius: 12px;
}

.mini-btn {
  padding: 6px 10px;
  font-size: 12px;
  border-radius: 10px;
}

.large-btn {
  width: 100%;
  padding: 16px;
  justify-content: flex-start;
  border-radius: 14px;
}

.rect-btn {
  width: 100%;
  padding: 16px 18px;
  border-radius: 14px;
  justify-content: flex-start;
}

.btn-icon {
  font-size: 24px;
  flex-shrink: 0;
  display: flex;
  align-items: center;
  justify-content: center;
}

.btn-icon .svg-icon {
  width: 26px;
  height: 26px;
}

.btn-text {
  display: flex;
  flex-direction: column;
  text-align: left;
}

.btn-text strong {
  font-size: 16px;
  line-height: 1.2;
}

.btn-text small {
  font-size: 12px;
  font-weight: normal;
  opacity: 0.8;
  margin-top: 2px;
}

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

/* --- SCREEN 1: MAIN MENU & INTRO BANNER --- */
.intro-banner-card {
  background: linear-gradient(135deg, var(--bg-secondary) 0%, var(--bg-card) 100%);
  border: 2px solid var(--accent-color);
  border-radius: 16px;
  padding: 18px 20px;
  text-align: center;
  box-shadow: var(--shadow-chunky);
}

.quote-content {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.quote-text {
  font-size: 15px;
  font-weight: 700;
  font-style: italic;
  color: var(--text-main);
  line-height: 1.45;
}

.quote-author {
  font-size: 13px;
  font-weight: 800;
  color: var(--accent-color);
  text-align: right;
}

.user-auth-bar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  background-color: var(--bg-secondary);
  border: 2px solid var(--border-color);
  border-radius: 14px;
  padding: 8px 14px;
}

.user-status-text {
  font-size: 13px;
  font-weight: 700;
  color: var(--text-muted);
}

.user-logged-in-name {
  font-size: 13px;
  font-weight: 800;
  color: var(--accent-color);
}

.menu-buttons-stack {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

/* --- SCREEN 2: SCANNER & MANUAL INPUT --- */
.scanner-card {
  background-color: var(--bg-secondary);
  border: 2px solid var(--border-color);
  border-radius: 20px;
  padding: 16px;
  box-shadow: var(--shadow-chunky);
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.camera-wrapper {
  position: relative;
  width: 100%;
  aspect-ratio: 4/3;
  background-color: #000000;
  border-radius: 14px;
  overflow: hidden;
  border: 2px solid var(--border-color);
}

#reader {
  width: 100%;
  height: 100%;
}

#reader video {
  object-fit: cover !important;
  width: 100% !important;
  height: 100% !important;
}

.camera-status {
  position: absolute;
  bottom: 8px;
  left: 8px;
  right: 8px;
  background: rgba(0, 0, 0, 0.7);
  color: #ffffff;
  font-size: 12px;
  padding: 6px 12px;
  border-radius: 8px;
  text-align: center;
}

.scanner-actions {
  display: flex;
  justify-content: center;
}

.divider {
  display: flex;
  align-items: center;
  text-align: center;
  color: var(--text-muted);
  font-size: 13px;
  font-weight: 600;
}

.divider::before,
.divider::after {
  content: '';
  flex: 1;
  border-bottom: 2px dashed var(--border-color);
}

.divider span {
  padding: 0 10px;
}

.manual-input-form {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.input-label {
  font-size: 14px;
  font-weight: 700;
}

.input-group {
  display: flex;
  gap: 8px;
}

.chunky-input, .chunky-select {
  flex: 1;
  background-color: var(--bg-card);
  color: var(--text-main);
  border: 2px solid var(--border-color);
  border-radius: 14px;
  padding: 10px 14px;
  font-size: 14px;
  font-weight: 600;
  outline: none;
  transition: border-color 0.2s ease;
}

.chunky-input:focus, .chunky-select:focus {
  border-color: var(--accent-color);
}

.input-hint {
  font-size: 12px;
  color: var(--text-muted);
}

/* MULTI-LIBRARY SELECTOR & GENRE TABS */
.library-selector-container {
  padding: 8px 0;
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.library-selector-header {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.add-library-pill-btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  align-self: flex-start;
  padding: 8px 16px;
}

.plus-round {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 24px;
  height: 24px;
  border-radius: 50%;
  background-color: rgba(255, 255, 255, 0.25);
  font-weight: 800;
  font-size: 16px;
  line-height: 1;
}

.libraries-grid {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.library-card-item {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 14px 18px;
  background-color: var(--bg-card);
  border: 2px solid var(--border-color);
  border-radius: 14px;
  cursor: pointer;
  transition: transform 0.15s ease, border-color 0.15s ease;
}

.library-card-item:hover {
  transform: translateY(-2px);
  border-color: var(--accent-color);
}

.library-card-icon {
  font-size: 28px;
}

.library-card-info {
  flex: 1;
}

.library-card-title {
  font-size: 16px;
  font-weight: 800;
  color: var(--text-main);
  margin-bottom: 2px;
}

.library-card-count {
  font-size: 13px;
  color: var(--text-muted);
}

.library-card-arrow {
  font-size: 18px;
  color: var(--accent-color);
  font-weight: 800;
}

.genre-legend-card {
  background-color: var(--bg-card);
  border: 2px solid var(--border-color);
  border-radius: 14px;
  padding: 12px 16px;
  margin-top: 10px;
}

.legend-toggle-btn {
  width: 100%;
  background: none;
  border: none;
  color: var(--text-main);
  font-size: 16px;
  font-weight: 800;
  display: flex;
  justify-content: space-between;
  align-items: center;
  cursor: pointer;
  padding: 4px 0;
}

.legend-content {
  margin-top: 12px;
  transition: all 0.2s ease;
}

.legend-content.hidden {
  display: none;
}

.legend-subtitle {
  font-size: 13px;
  color: var(--text-muted);
  margin-bottom: 12px;
}

.genre-legend-grid {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.legend-item {
  background-color: rgba(255, 255, 255, 0.03);
  padding: 8px 12px;
  border-radius: 8px;
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.legend-desc {
  font-size: 12px;
  color: var(--text-main);
}

.genre-badge {
  display: inline-block;
  font-size: 11px;
  padding: 3px 8px;
  border-radius: 6px;
  font-weight: 800;
  letter-spacing: 0.3px;
}

.genre-pill {
  display: inline-block;
  font-size: 12px;
  padding: 4px 10px;
  border-radius: 6px;
  font-weight: 800;
  letter-spacing: 0.3px;
}

.genre-tabs-container {
  display: flex;
  gap: 8px;
  overflow-x: auto;
  padding-bottom: 6px;
  scrollbar-width: thin;
}

.genre-tab-btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 6px 12px;
  border-radius: 20px;
  font-size: 12px;
  font-weight: 700;
  white-space: nowrap;
  background-color: var(--bg-card);
  border: 2px solid var(--border-color);
  color: var(--text-main);
  cursor: pointer;
  transition: all 0.15s ease;
}

.genre-tab-btn.active {
  background-color: var(--accent-color);
  color: #fff;
  border-color: var(--accent-color);
}

.genre-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  display: inline-block;
}

/* --- SCREEN 3: LIBRARY --- */
.library-controls {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

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

.search-icon {
  position: absolute;
  left: 12px;
  pointer-events: none;
  display: flex;
  align-items: center;
}

.search-input {
  padding-left: 38px;
  padding-right: 38px;
  width: 100%;
}

.clear-btn {
  position: absolute;
  right: 12px;
  background: none;
  border: none;
  color: var(--text-muted);
  font-size: 16px;
  cursor: pointer;
  padding: 4px;
}

.clear-btn.hidden {
  display: none;
}

.library-toolbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  background-color: var(--bg-secondary);
  border: 2px solid var(--border-color);
  border-radius: 14px;
  padding: 8px 12px;
}

.count-badge {
  font-size: 13px;
  color: var(--text-muted);
}

.count-badge strong {
  color: var(--accent-color);
  font-size: 15px;
}

.tool-buttons {
  display: flex;
  gap: 6px;
}

.library-body {
  display: flex;
  position: relative;
  gap: 8px;
  min-height: 400px;
}

.books-list {
  flex: 1;
  display: flex;
  flex-direction: column;
  gap: 12px;
  padding-bottom: 40px;
}

/* Alphabet Jump Sidebar */
.alphabet-sidebar {
  position: sticky;
  top: 70px;
  height: calc(100vh - 180px);
  max-height: 520px;
  width: 28px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  align-items: center;
  background-color: var(--bg-secondary);
  border: 2px solid var(--border-color);
  border-radius: 14px;
  padding: 4px 0;
  user-select: none;
  z-index: 10;
}

.alpha-letter {
  font-size: 10px;
  font-weight: 800;
  color: var(--text-muted);
  background: none;
  border: none;
  cursor: pointer;
  padding: 1px 2px;
  width: 100%;
  text-align: center;
  border-radius: 4px;
}

.alpha-letter.active,
.alpha-letter:hover {
  color: var(--accent-color);
  background-color: var(--bg-hover);
}

/* Book Card Item */
.book-card {
  background-color: var(--bg-secondary);
  border: 2px solid var(--border-color);
  border-radius: 16px;
  padding: 12px;
  display: flex;
  align-items: center;
  gap: 12px;
  box-shadow: var(--shadow-chunky);
  position: relative;
  transition: transform 0.15s ease;
}

.book-cover {
  width: 65px;
  height: 90px;
  background-color: var(--bg-card);
  border: 2px solid var(--border-color);
  border-radius: 8px;
  object-fit: cover;
  flex-shrink: 0;
}

.book-cover-placeholder {
  width: 65px;
  height: 90px;
  background-color: var(--bg-card);
  border: 2px solid var(--border-color);
  border-radius: 8px;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  color: var(--text-muted);
  flex-shrink: 0;
}

.book-info {
  flex: 1;
  display: flex;
  flex-direction: column;
  justify-content: center;
  overflow: hidden;
  padding-right: 4px;
}

.book-title {
  font-size: 15px;
  font-weight: 800;
  color: var(--text-main);
  line-height: 1.25;
  margin-bottom: 4px;
  word-break: break-word;
}

.book-author {
  font-size: 13px;
  color: var(--accent-color);
  font-weight: 600;
  margin-bottom: 4px;
}

.book-meta {
  font-size: 11px;
  color: var(--text-muted);
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}

.book-actions-col {
  display: flex;
  flex-direction: column;
  gap: 4px;
  align-items: center;
  justify-content: center;
  padding-left: 4px;
}

.fav-heart-btn,
.manage-libs-btn,
.share-book-btn,
.delete-book-btn {
  background: var(--bg-card);
  border: 2px solid var(--border-color);
  cursor: pointer;
  padding: 6px;
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all 0.15s ease;
  font-size: 14px;
  line-height: 1;
}

.fav-heart-btn:hover,
.manage-libs-btn:hover {
  background-color: var(--bg-hover);
  transform: scale(1.1);
}

.library-checkbox-list {
  display: flex;
  flex-direction: column;
  gap: 8px;
  margin-top: 10px;
}

.library-checkbox-item {
  display: flex;
  align-items: center;
  gap: 10px;
  background-color: var(--bg-card);
  border: 2px solid var(--border-color);
  border-radius: 12px;
  padding: 10px 14px;
  cursor: pointer;
  font-weight: 700;
  font-size: 14px;
}

.library-checkbox-item input[type="checkbox"] {
  width: 18px;
  height: 18px;
  accent-color: var(--accent-color);
}

.share-book-btn {
  color: var(--accent-color);
}

.share-book-btn:hover {
  background-color: var(--accent-color);
  color: #ffffff;
  border-color: var(--accent-color);
}

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

.delete-book-btn:hover {
  background-color: var(--danger-color);
  color: #ffffff;
  border-color: var(--danger-color);
}

.empty-library {
  text-align: center;
  padding: 40px 20px;
  background-color: var(--bg-secondary);
  border: 2px dashed var(--border-color);
  border-radius: 20px;
  color: var(--text-muted);
}

.empty-library h3 {
  font-size: 18px;
  color: var(--text-main);
  margin-bottom: 8px;
}


/* --- SCREEN 4: RECOMMENDED BOOKS & STAR RATINGS --- */
.monthly-header-card {
  background-color: var(--bg-secondary);
  border: 2px solid var(--border-color);
  border-radius: 18px;
  padding: 16px;
  box-shadow: var(--shadow-chunky);
}

.monthly-header-card h3 {
  font-size: 18px;
  font-weight: 800;
  color: var(--accent-color);
  margin-bottom: 4px;
}

.monthly-header-card p {
  font-size: 13px;
  color: var(--text-muted);
}

.monthly-books-list {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.monthly-book-card {
  background-color: var(--bg-secondary);
  border: 2px solid var(--border-color);
  border-radius: 20px;
  padding: 16px;
  box-shadow: var(--shadow-chunky);
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.monthly-book-main {
  display: flex;
  gap: 14px;
}

.star-rating-picker {
  display: flex;
  align-items: center;
  gap: 4px;
  margin-top: 6px;
}

.star-btn {
  background: none;
  border: none;
  cursor: pointer;
  padding: 2px;
  color: var(--border-color);
  transition: transform 0.1s ease;
}

.star-btn.active {
  color: var(--star-color);
}

.star-btn:active {
  transform: scale(1.2);
}

.comment-input-area {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.comment-textarea {
  width: 100%;
  background-color: var(--bg-card);
  color: var(--text-main);
  border: 2px solid var(--border-color);
  border-radius: 12px;
  padding: 10px;
  font-size: 13px;
  outline: none;
  resize: vertical;
  min-height: 50px;
}

.comment-textarea:focus {
  border-color: var(--accent-color);
}

.reviews-list {
  display: flex;
  flex-direction: column;
  gap: 8px;
  margin-top: 6px;
}

.review-item {
  background-color: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 10px;
  padding: 8px 12px;
  font-size: 12px;
}

.review-item-header {
  display: flex;
  justify-content: space-between;
  margin-bottom: 2px;
  font-weight: 700;
  color: var(--text-muted);
}

.review-stars {
  color: var(--star-color);
}


/* --- SCREEN 5: SOCIAL - ACCOUNTS & FRIENDS --- */
.social-card {
  background-color: var(--bg-secondary);
  border: 2px solid var(--border-color);
  border-radius: 20px;
  padding: 16px;
  box-shadow: var(--shadow-chunky);
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.social-card h3 {
  font-size: 17px;
  font-weight: 800;
  color: var(--accent-color);
}

.social-card p {
  font-size: 13px;
  color: var(--text-muted);
}

.accounts-list {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.account-item {
  display: flex;
  justify-content: space-between;
  align-items: center;
  background-color: var(--bg-card);
  border: 2px solid var(--border-color);
  border-radius: 14px;
  padding: 10px 14px;
}

.account-info {
  display: flex;
  flex-direction: column;
}

.account-name {
  font-size: 14px;
  font-weight: 700;
}

.account-handle {
  font-size: 12px;
  color: var(--text-muted);
}


/* --- SCREEN 6: SETTINGS --- */
.settings-card {
  background-color: var(--bg-secondary);
  border: 2px solid var(--border-color);
  border-radius: 20px;
  padding: 8px 16px;
  box-shadow: var(--shadow-chunky);
}

.setting-item {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 16px 0;
  border-bottom: 1px solid var(--border-color);
}

.setting-item:last-child {
  border-bottom: none;
}

.setting-info {
  display: flex;
  flex-direction: column;
  gap: 4px;
  max-width: 75%;
}

.setting-title {
  font-size: 15px;
  font-weight: 700;
}

.setting-desc {
  font-size: 12px;
  color: var(--text-muted);
  line-height: 1.3;
}

/* Lightswitch Toggle */
.lightswitch {
  position: relative;
  display: inline-block;
  width: 54px;
  height: 30px;
}

.lightswitch input {
  opacity: 0;
  width: 0;
  height: 0;
}

.switch-slider {
  position: absolute;
  cursor: pointer;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background-color: #38383a;
  border: 2px solid var(--border-color);
  transition: .25s;
  border-radius: 30px;
}

.switch-slider:before {
  position: absolute;
  content: "";
  height: 20px;
  width: 20px;
  left: 3px;
  bottom: 3px;
  background-color: white;
  transition: .25s;
  border-radius: 50%;
}

input:checked + .switch-slider {
  background-color: var(--accent-color);
}

input:checked + .switch-slider:before {
  transform: translateX(24px);
}

/* --- MODALS & OVERLAYS --- */
.modal-overlay {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background-color: rgba(0, 0, 0, 0.85);
  backdrop-filter: blur(6px);
  display: flex;
  justify-content: center;
  align-items: center;
  padding: 20px;
  z-index: 1000;
  animation: fadeIn 0.2s ease-out;
}

.modal-overlay.hidden {
  display: none;
}

.modal-card {
  width: 100%;
  max-width: 420px;
  background-color: var(--bg-secondary);
  border: 3px solid var(--border-color);
  border-radius: 24px;
  padding: 20px;
  box-shadow: var(--shadow-modal);
  display: flex;
  flex-direction: column;
  gap: 16px;
  max-height: 90vh;
  overflow-y: auto;
}

.modal-header h3 {
  font-size: 20px;
  font-weight: 800;
  color: var(--accent-color);
}

.preview-book-card {
  display: flex;
  gap: 14px;
  background-color: var(--bg-card);
  border: 2px solid var(--border-color);
  border-radius: 16px;
  padding: 12px;
}

.preview-book-cover {
  width: 80px;
  height: 110px;
  object-fit: cover;
  border-radius: 8px;
  border: 1px solid var(--border-color);
}

.preview-book-details {
  flex: 1;
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.preview-title {
  font-size: 16px;
  font-weight: 800;
  line-height: 1.25;
}

.preview-author {
  font-size: 13px;
  color: var(--accent-color);
  font-weight: 700;
}

.preview-meta {
  font-size: 12px;
  color: var(--text-muted);
}

.duplicate-warning {
  background-color: rgba(255, 69, 0, 0.15);
  border: 2px solid var(--accent-color);
  color: var(--accent-color);
  padding: 10px 14px;
  border-radius: 12px;
  font-size: 13px;
  text-align: center;
}

.duplicate-warning.hidden {
  display: none;
}

.modal-actions {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.modal-actions .chunky-btn {
  width: 100%;
}

/* Loading Card */
.loading-card {
  align-items: center;
  text-align: center;
  padding: 30px;
}

.spinner {
  width: 40px;
  height: 40px;
  border: 4px solid var(--border-color);
  border-top-color: var(--accent-color);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
}

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

#loading-text {
  font-weight: 700;
  font-size: 15px;
}

/* Error Card */
.error-card {
  text-align: center;
  align-items: center;
}

.error-card h3 {
  font-size: 20px;
  font-weight: 800;
}

.error-card p {
  color: var(--text-muted);
  font-size: 14px;
  line-height: 1.4;
}