/* ========================================
   GeoShelf - Stylesheet
   ======================================== */

:root {
  --primary: #1b4332;
  --primary-light: #2d6a4f;
  --primary-lighter: #40916c;
  --primary-bg: #d8f3dc;
  --primary-bg-light: #f0faf2;
  --accent: #c9a84c;
  --bg: #ffffff;
  --bg-alt: #f8f9fa;
  --text: #212529;
  --text-light: #6c757d;
  --text-lighter: #adb5bd;
  --border: #e9ecef;
  --border-light: #f1f3f5;
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.06);
  --shadow: 0 2px 8px rgba(0,0,0,0.08);
  --shadow-lg: 0 8px 24px rgba(0,0,0,0.12);
  --radius: 8px;
  --radius-lg: 12px;
  --transition: 0.2s ease;
}

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

body {
  font-family: 'Pretendard', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  color: var(--text);
  background: var(--bg);
  line-height: 1.6;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
}

.container--narrow {
  max-width: 640px;
}

/* ---- Header ---- */
.header {
  background: var(--bg);
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  z-index: 100;
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
  color: var(--primary);
}

.logo-icon { flex-shrink: 0; }

.logo-text {
  font-size: 20px;
  font-weight: 700;
  letter-spacing: -0.5px;
}

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

.nav-link {
  text-decoration: none;
  color: var(--text);
  font-size: 14px;
  font-weight: 500;
  padding: 8px 16px;
  border-radius: 6px;
  transition: background var(--transition), color var(--transition);
}

.nav-link:hover {
  background: var(--bg-alt);
  color: var(--primary);
}

.nav-link--admin {
  color: var(--text-light);
}

.mobile-menu-btn {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
}

.mobile-menu-btn span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--text);
  border-radius: 2px;
  transition: var(--transition);
}

.mobile-nav {
  display: none;
  padding: 0 24px 16px;
  flex-direction: column;
  gap: 4px;
  border-bottom: 1px solid var(--border);
}

.mobile-nav.open { display: flex; }

.mobile-nav-link {
  text-decoration: none;
  color: var(--text);
  font-size: 15px;
  padding: 10px 0;
  border-bottom: 1px solid var(--border-light);
}

/* ---- Hero / Search ---- */
.hero {
  background: var(--primary-bg-light);
  padding: 48px 0 40px;
  text-align: center;
}

.hero-title {
  font-size: 32px;
  font-weight: 700;
  color: var(--primary);
  margin-bottom: 8px;
  letter-spacing: -0.5px;
}

.hero-desc {
  font-size: 16px;
  color: var(--text-light);
  margin-bottom: 28px;
}

.search-box {
  position: relative;
  max-width: 560px;
  margin: 0 auto;
}

.search-icon {
  position: absolute;
  left: 16px;
  top: 50%;
  transform: translateY(-50%);
  pointer-events: none;
}

.search-input {
  width: 100%;
  padding: 14px 20px 14px 48px;
  font-size: 15px;
  border: 1px solid var(--border);
  border-radius: 40px;
  outline: none;
  background: var(--bg);
  transition: border-color var(--transition), box-shadow var(--transition);
  font-family: inherit;
}

.search-input:focus {
  border-color: var(--primary-lighter);
  box-shadow: 0 0 0 3px rgba(45,106,79,0.1);
}

.search-input::placeholder { color: var(--text-lighter); }

/* ---- Filter Section ---- */
.filter-section {
  padding: 20px 0;
  border-bottom: 1px solid var(--border-light);
  background: var(--bg);
}

.filter-group {
  display: flex;
  align-items: flex-start;
  gap: 12px;
  margin-bottom: 12px;
}

.filter-group:last-child { margin-bottom: 0; }

.filter-group--level-row {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 16px;
}

.filter-group__left {
  display: flex;
  align-items: flex-start;
  gap: 12px;
}

.filter-group__right {
  display: flex;
  align-items: center;
  gap: 8px;
  flex-shrink: 0;
}

.filter-group__right .filter-label {
  padding-top: 0;
  white-space: nowrap;
}

.project-select {
  padding: 6px 32px 6px 12px;
  font-size: 13px;
  font-family: inherit;
  border: 1px solid var(--border);
  border-radius: 20px;
  background: var(--bg);
  color: var(--text);
  cursor: pointer;
  appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg width='10' height='6' viewBox='0 0 10 6' xmlns='http://www.w3.org/2000/svg'%3E%3Cpath d='M1 1l4 4 4-4' stroke='%236c757d' stroke-width='1.5' fill='none' stroke-linecap='round'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 12px center;
  max-width: 320px;
  transition: border-color var(--transition);
}

.project-select:focus {
  outline: none;
  border-color: var(--primary);
}

.filter-label {
  font-size: 13px;
  font-weight: 600;
  color: var(--text-light);
  min-width: 48px;
  padding-top: 7px;
  flex-shrink: 0;
}

.filter-chips {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}

.chip {
  padding: 6px 14px;
  font-size: 13px;
  font-weight: 500;
  border: 1px solid var(--border);
  border-radius: 20px;
  background: var(--bg);
  color: var(--text);
  cursor: pointer;
  transition: all var(--transition);
  font-family: inherit;
  white-space: nowrap;
}

.chip:hover {
  border-color: var(--primary-lighter);
  color: var(--primary);
  background: var(--primary-bg-light);
}

.chip.active {
  background: var(--primary);
  color: #fff;
  border-color: var(--primary);
}

.chip-new {
  border-color: #e03131;
  color: #e03131;
  font-weight: 700;
}

.chip-new:hover {
  background: #fff5f5;
  border-color: #e03131;
  color: #e03131;
}

.chip-new.active {
  background: #e03131;
  color: #fff;
  border-color: #e03131;
}

.book-card {
  position: relative;
}

.new-badge {
  position: absolute;
  top: 8px;
  left: 8px;
  z-index: 2;
  font-size: 11px;
  font-weight: 800;
  color: #fff;
  background: #e03131;
  padding: 2px 7px;
  border-radius: 4px;
  line-height: 1.4;
  box-shadow: 0 1px 4px rgba(224,49,49,0.3);
}

/* ---- Hierarchical Filter ---- */
.filter-chips-wrap {
  display: flex;
  flex-direction: column;
  gap: 8px;
  flex: 1;
}

.filter-sub-chips {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  padding: 8px 12px;
  background: var(--bg-alt);
  border-radius: var(--radius);
  border: 1px solid var(--border-light);
}

.filter-sub-chips .chip {
  font-size: 12px;
  padding: 4px 12px;
}

.chip-parent.active {
  background: var(--primary-light);
}

/* ---- Buy Links (Modal) ---- */
.buy-links {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 20px;
}

.buy-btn {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  padding: 8px 16px;
  font-size: 13px;
  font-weight: 600;
  text-decoration: none;
  border-radius: 6px;
  transition: all var(--transition);
  border: 1px solid;
}

.buy-btn--kyobo {
  background: #00a651;
  color: #fff;
  border-color: #00a651;
}
.buy-btn--kyobo:hover { background: #00bf5c; }

.buy-btn--yes24 {
  background: #0074E4;
  color: #fff;
  border-color: #0074E4;
}
.buy-btn--yes24:hover { background: #1a85f0; }

.buy-btn--aladin {
  background: #e84887;
  color: #fff;
  border-color: #e84887;
}
.buy-btn--aladin:hover { background: #f05a96; }

.buy-btn--etc {
  background: var(--bg);
  color: var(--text);
  border-color: var(--border);
}
.buy-btn--etc:hover { border-color: var(--primary-lighter); color: var(--primary); }

/* ---- Results Section ---- */
.results-section {
  flex: 1;
  padding: 24px 0 48px;
}

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

.result-count {
  font-size: 14px;
  color: var(--text-light);
}

.page-size-select {
  padding: 5px 28px 5px 10px;
  font-size: 13px;
  font-family: inherit;
  border: 1px solid var(--border);
  border-radius: 6px;
  background: var(--bg);
  color: var(--text);
  cursor: pointer;
  appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg width='10' height='6' viewBox='0 0 10 6' xmlns='http://www.w3.org/2000/svg'%3E%3Cpath d='M1 1l4 4 4-4' stroke='%236c757d' stroke-width='1.5' fill='none' stroke-linecap='round'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 8px center;
}

.page-size-select:focus {
  outline: none;
  border-color: var(--primary);
}

/* ---- Pagination ---- */
.pagination {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 4px;
  margin-top: 32px;
  padding-bottom: 8px;
}

.page-btn {
  min-width: 36px;
  height: 36px;
  padding: 0 8px;
  border: 1px solid var(--border);
  border-radius: 6px;
  background: var(--bg);
  color: var(--text);
  font-size: 14px;
  font-family: inherit;
  cursor: pointer;
  transition: all var(--transition);
}

.page-btn:hover:not([disabled]):not(.active) {
  border-color: var(--primary-lighter);
  color: var(--primary);
}

.page-btn.active {
  background: var(--primary);
  border-color: var(--primary);
  color: #fff;
  font-weight: 600;
}

.page-btn[disabled] {
  opacity: 0.35;
  cursor: default;
}

.result-count strong {
  color: var(--primary);
  font-weight: 700;
}

/* ---- Book Grid ---- */
.book-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  gap: 24px;
}

.book-card {
  background: var(--bg);
  border-radius: var(--radius-lg);
  overflow: hidden;
  border: 1px solid var(--border);
  cursor: pointer;
  transition: transform var(--transition), box-shadow var(--transition);
}

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

.book-card .cover-wrap {
  width: 100%;
  aspect-ratio: 3 / 4;
  overflow: hidden;
  background: var(--bg-alt);
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
}

.book-card .cover-wrap img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.cover-placeholder {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  width: 100%;
  height: 100%;
  gap: 8px;
}

.cover-placeholder svg { opacity: 0.3; }

.cover-placeholder span {
  font-size: 12px;
  color: var(--text-lighter);
  font-weight: 500;
}

.book-card .info {
  padding: 14px 16px 16px;
}

.book-card .book-title {
  font-size: 14px;
  font-weight: 700;
  line-height: 1.4;
  margin-bottom: 4px;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
  color: var(--text);
}

.book-card .book-subtitle {
  font-size: 12px;
  color: var(--text-lighter);
  line-height: 1.3;
  margin-bottom: 4px;
  display: -webkit-box;
  -webkit-line-clamp: 1;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.book-card .book-author {
  font-size: 12px;
  color: var(--text-light);
  margin-bottom: 2px;
}

.book-card .book-publisher {
  font-size: 12px;
  color: var(--text-lighter);
  margin-bottom: 10px;
}

.book-card .badges {
  display: flex;
  flex-wrap: wrap;
  gap: 4px;
}

.badge {
  font-size: 11px;
  font-weight: 600;
  padding: 2px 8px;
  border-radius: 10px;
  white-space: nowrap;
}

.badge--level {
  background: var(--primary-bg);
  color: var(--primary);
}

.badge--content {
  background: #fff3cd;
  color: #856404;
}

/* ---- Loading & Empty ---- */
.loading {
  text-align: center;
  padding: 60px 0;
  color: var(--text-light);
  font-size: 14px;
}

.spinner {
  width: 32px;
  height: 32px;
  border: 3px solid var(--border);
  border-top-color: var(--primary);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
  margin: 0 auto 12px;
}

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

.empty-state {
  text-align: center;
  padding: 60px 0;
  color: var(--text-lighter);
}

.empty-state svg { margin-bottom: 12px; }

.empty-state p { font-size: 15px; }

/* ---- Modal ---- */
.modal-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,0.5);
  display: none;
  align-items: center;
  justify-content: center;
  z-index: 200;
  padding: 24px;
  backdrop-filter: blur(2px);
}

.modal-overlay.open { display: flex; }

.modal {
  background: var(--bg);
  border-radius: var(--radius-lg);
  max-width: 680px;
  width: 100%;
  max-height: 85vh;
  overflow-y: auto;
  position: relative;
  box-shadow: var(--shadow-lg);
}

.modal--sm { max-width: 400px; }

.modal-close {
  position: absolute;
  top: 16px;
  right: 16px;
  background: none;
  border: none;
  font-size: 28px;
  cursor: pointer;
  color: var(--text-light);
  width: 36px;
  height: 36px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 50%;
  transition: background var(--transition);
  z-index: 1;
}

.modal-close:hover { background: var(--bg-alt); }

.modal-body { padding: 32px; }

.modal-detail {
  display: flex;
  gap: 28px;
}

.modal-cover {
  width: 200px;
  flex-shrink: 0;
  border-radius: var(--radius);
  overflow: hidden;
  background: var(--bg-alt);
  aspect-ratio: 3/4;
  display: flex;
  align-items: center;
  justify-content: center;
}

.modal-cover img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

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

.modal-info h2 {
  font-size: 22px;
  font-weight: 700;
  margin-bottom: 16px;
  line-height: 1.3;
  color: var(--primary);
}

.modal-subtitle {
  font-size: 14px;
  color: var(--text-lighter);
  margin-top: -12px;
  margin-bottom: 16px;
  line-height: 1.4;
}

.detail-row {
  display: flex;
  padding: 8px 0;
  border-bottom: 1px solid var(--border-light);
  font-size: 14px;
}

.detail-label {
  width: 72px;
  flex-shrink: 0;
  color: var(--text-light);
  font-weight: 500;
}

.detail-value {
  color: var(--text);
  word-break: break-all;
}

.modal-badges {
  display: flex;
  gap: 6px;
  margin-top: 16px;
}

.modal-buy-link {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  margin-top: 20px;
  padding: 10px 24px;
  background: var(--primary);
  color: #fff;
  text-decoration: none;
  border-radius: 6px;
  font-size: 14px;
  font-weight: 600;
  transition: background var(--transition);
}

.modal-buy-link:hover { background: var(--primary-light); }

/* ---- Footer ---- */
.footer {
  background: var(--bg-alt);
  border-top: 1px solid var(--border);
  padding: 20px 0;
  margin-top: auto;
}

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

.visitor-stats {
  display: flex;
  align-items: center;
  gap: 12px;
  font-size: 13px;
  color: var(--text-light);
}

.visitor-stats strong {
  color: var(--primary);
  font-weight: 700;
}

.stat-divider { color: var(--border); }

.copyright {
  font-size: 12px;
  color: var(--text-lighter);
}

/* ---- Page Section (register, admin) ---- */
.page-section {
  flex: 1;
  padding: 48px 0;
}

.page-header {
  text-align: center;
  margin-bottom: 36px;
}

.page-title {
  font-size: 24px;
  font-weight: 700;
  color: var(--text);
  margin-bottom: 8px;
}

.page-desc {
  font-size: 15px;
  color: var(--text-light);
}

/* ---- Form ---- */
.form { display: flex; flex-direction: column; gap: 20px; }

.form-group { display: flex; flex-direction: column; gap: 6px; }

.form-label {
  font-size: 14px;
  font-weight: 600;
  color: var(--text);
}

.form-label--sub {
  font-weight: 500;
  font-size: 13px;
  color: var(--text-light);
}

.required { color: #e03131; }

.form-input,
.form-select {
  padding: 10px 14px;
  font-size: 14px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  outline: none;
  background: var(--bg);
  font-family: inherit;
  transition: border-color var(--transition), box-shadow var(--transition);
}

.form-input:focus,
.form-select:focus {
  border-color: var(--primary-lighter);
  box-shadow: 0 0 0 3px rgba(45,106,79,0.1);
}

.form-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
}

/* Cover Upload */
.cover-upload { cursor: pointer; }

.cover-preview {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 8px;
  border: 2px dashed var(--border);
  border-radius: var(--radius-lg);
  padding: 40px;
  transition: border-color var(--transition), background var(--transition);
  color: var(--text-lighter);
  font-size: 14px;
}

.cover-preview:hover {
  border-color: var(--primary-lighter);
  background: var(--primary-bg-light);
}

.cover-img {
  max-width: 200px;
  max-height: 260px;
  object-fit: cover;
  border-radius: var(--radius);
  border: 1px solid var(--border);
}

/* ---- Buttons ---- */
.btn {
  padding: 10px 20px;
  font-size: 14px;
  font-weight: 600;
  border: none;
  border-radius: var(--radius);
  cursor: pointer;
  font-family: inherit;
  transition: all var(--transition);
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
}

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

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

.btn-primary:disabled {
  background: var(--text-lighter);
  cursor: not-allowed;
}

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

.btn-outline:hover { border-color: var(--primary-lighter); color: var(--primary); }

.btn-ghost {
  background: transparent;
  color: var(--text-light);
}

.btn-ghost:hover { color: var(--text); background: var(--bg-alt); }

.btn-danger {
  background: #fff;
  color: #e03131;
  border: 1px solid #ffc9c9;
}

.btn-danger:hover { background: #fff5f5; }

.btn-success {
  background: var(--primary);
  color: #fff;
}

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

.btn-block { width: 100%; }

.btn-sm { padding: 6px 12px; font-size: 13px; }

/* ---- Admin ---- */
.admin-login {
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 400px;
}

.admin-login-box {
  max-width: 400px;
  width: 100%;
  text-align: center;
}

.admin-login-box .form-group { margin: 24px 0 16px; }

.admin-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 24px;
  flex-wrap: wrap;
  gap: 12px;
}

.admin-actions {
  display: flex;
  align-items: center;
  gap: 8px;
}

.pending-count {
  font-size: 14px;
  color: var(--text-light);
  font-weight: 500;
  background: var(--primary-bg);
  padding: 4px 12px;
  border-radius: 12px;
  color: var(--primary);
}

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

.pending-card {
  display: flex;
  gap: 20px;
  padding: 20px;
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  background: var(--bg);
  transition: box-shadow var(--transition);
}

.pending-card:hover { box-shadow: var(--shadow); }

.pending-cover {
  width: 100px;
  aspect-ratio: 3/4;
  flex-shrink: 0;
  border-radius: var(--radius);
  overflow: hidden;
  background: var(--bg-alt);
  display: flex;
  align-items: center;
  justify-content: center;
}

.pending-cover img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

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

.pending-info h3 {
  font-size: 16px;
  font-weight: 700;
  margin-bottom: 6px;
}

.pending-meta {
  font-size: 13px;
  color: var(--text-light);
  margin-bottom: 4px;
}

.pending-badges {
  display: flex;
  gap: 4px;
  margin: 8px 0 12px;
}

.pending-actions {
  display: flex;
  gap: 8px;
}

.admin-search-box {
  margin-bottom: 16px;
}

.admin-search-box .form-input {
  max-width: 360px;
}

.error-msg {
  color: #e03131;
  font-size: 13px;
  margin-top: 8px;
}

/* ---- Confirm Modal ---- */
.confirm-body {
  text-align: center;
}

.confirm-body p {
  font-size: 16px;
  margin-bottom: 24px;
  line-height: 1.5;
}

.confirm-actions {
  display: flex;
  gap: 8px;
  justify-content: center;
}

/* ---- ISBN Info ---- */
.isbn-info-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 18px;
  height: 18px;
  font-size: 11px;
  font-weight: 700;
  color: var(--text-lighter);
  background: var(--bg-alt);
  border: 1px solid var(--border);
  border-radius: 50%;
  cursor: pointer;
  margin-left: 4px;
  vertical-align: middle;
  padding: 0;
  font-family: inherit;
  transition: all var(--transition);
}

.isbn-info-btn:hover {
  background: var(--border);
  color: var(--text-light);
}

.isbn-error {
  font-size: 12px;
  color: #e03131;
  display: none;
}

.isbn-error.show {
  display: block;
}

.isbn-dialog-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,0.4);
  display: none;
  align-items: center;
  justify-content: center;
  z-index: 250;
  padding: 24px;
  backdrop-filter: blur(2px);
}

.isbn-dialog-overlay.open {
  display: flex;
}

.isbn-dialog {
  background: var(--bg);
  border-radius: var(--radius-lg);
  max-width: 440px;
  width: 100%;
  box-shadow: var(--shadow-lg);
  overflow: hidden;
}

.isbn-dialog-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 16px 20px;
  border-bottom: 1px solid var(--border);
  background: var(--primary-bg-light);
}

.isbn-dialog-title {
  font-size: 16px;
  font-weight: 700;
  color: var(--primary);
}

.isbn-dialog-close {
  background: none;
  border: none;
  font-size: 24px;
  cursor: pointer;
  color: var(--text-light);
  width: 32px;
  height: 32px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 50%;
  transition: background var(--transition);
}

.isbn-dialog-close:hover {
  background: var(--border-light);
}

.isbn-dialog-body {
  padding: 20px;
}

.isbn-dialog-body p {
  font-size: 14px;
  color: var(--text);
  line-height: 1.7;
  margin-bottom: 12px;
}

.isbn-dialog-body p:last-of-type {
  margin-bottom: 16px;
}

.isbn-example {
  background: var(--bg-alt);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 10px 14px;
  font-size: 14px;
  color: var(--text-light);
}

.isbn-example code {
  font-weight: 700;
  color: var(--primary);
  font-size: 15px;
  letter-spacing: 0.5px;
}

/* ---- Toast ---- */
.toast {
  position: fixed;
  bottom: 24px;
  left: 50%;
  transform: translateX(-50%) translateY(100px);
  background: var(--text);
  color: #fff;
  padding: 12px 24px;
  border-radius: var(--radius);
  font-size: 14px;
  font-weight: 500;
  z-index: 300;
  opacity: 0;
  transition: transform 0.3s ease, opacity 0.3s ease;
  white-space: nowrap;
}

.toast.show {
  transform: translateX(-50%) translateY(0);
  opacity: 1;
}

.toast.success { background: var(--primary); }
.toast.error { background: #e03131; }

/* ---- Responsive ---- */
@media (max-width: 768px) {
  .nav { display: none; }
  .mobile-menu-btn { display: flex; }

  .hero { padding: 32px 0; }
  .hero-title { font-size: 24px; }
  .hero-desc { font-size: 14px; margin-bottom: 20px; }

  .filter-group { flex-direction: column; gap: 8px; }
  .filter-group--level-row { flex-direction: column; }
  .filter-group__left { flex-direction: column; gap: 8px; }
  .filter-group__right { margin-top: 4px; }
  .filter-label { padding-top: 0; }

  .book-grid {
    grid-template-columns: repeat(auto-fill, minmax(150px, 1fr));
    gap: 16px;
  }

  .book-card .info { padding: 10px 12px 12px; }
  .book-card .book-title { font-size: 13px; }

  .modal-detail { flex-direction: column; align-items: center; }
  .modal-cover { width: 160px; }
  .modal-body { padding: 24px; }

  .form-row { grid-template-columns: 1fr; }

  .footer-inner { flex-direction: column; gap: 8px; }

  .page-section { padding: 32px 0; }

  .admin-header { flex-direction: column; align-items: flex-start; }

  .pending-card { flex-direction: column; align-items: center; text-align: center; }
  .pending-cover { width: 120px; }
  .pending-badges { justify-content: center; }
  .pending-actions { justify-content: center; }
}

@media (max-width: 480px) {
  .container { padding: 0 16px; }

  .book-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 12px;
  }
}