/* ==========================================================================
   MainReads - Design System & Master Stylesheet
   A classic, lightweight, semantic CSS inspired by traditional libraries,
   early search engines, documentation portals, and reference directories.
   ========================================================================== */

/* --------------------------------------------------------------------------
   1. Design Tokens & CSS Custom Properties
   -------------------------------------------------------------------------- */
:root {
    /* Brand & Color Palette */
    --color-primary: #1e3a8a;          /* Authoritative Library Navy */
    --color-primary-hover: #172554;
    --color-primary-light: #eff6ff;
    --color-accent: #0284c7;           /* Balanced Cerulean */
    --color-accent-hover: #0369a1;
    --color-text: #0f172a;             /* High contrast deep slate */
    --color-text-body: #1e293b;        /* Readable body slate */
    --color-text-muted: #475569;       /* WCAG AA accessible muted text (contrast >= 5.0:1) */
    --color-text-light: #64748b;
    --color-bg: #ffffff;
    --color-bg-page: #fafafa;          /* Traditional warm off-white */
    --color-bg-surface: #ffffff;
    --color-bg-subtle: #f8fafc;
    --color-bg-warm: #fbfbfa;          /* Warm paper neutral */
    --color-border: #cbd5e1;           /* Crisp subtle border */
    --color-border-light: #e2e8f0;
    --color-border-dark: #94a3b8;
    --color-link: #0369a1;             /* Accessible contrast link color */
    --color-link-hover: #0c4a6e;
    --color-link-visited: #6b21a8;

    /* Semantic Status Palette */
    --color-success: #15803d;
    --color-success-bg: #f0fdf4;
    --color-success-border: #bbf7d0;
    --color-warning: #b45309;
    --color-warning-bg: #fffbeb;
    --color-warning-border: #fde68a;
    --color-danger: #b91c1c;
    --color-danger-bg: #fef2f2;
    --color-danger-border: #fecaca;
    --color-info: #0369a1;
    --color-info-bg: #f0f9ff;
    --color-info-border: #bae6fd;

    /* Commercial / Amazon */
    --color-amazon: #ff9900;
    --color-amazon-hover: #d88200;
    --color-amazon-dark: #111111;

    /* Typography */
    --font-sans: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    --font-serif: Georgia, Cambria, "Times New Roman", Times, serif;
    --font-mono: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace;

    /* Typographic Scale */
    --text-xs: 11px;
    --text-sm: 12px;
    --text-base: 14px;
    --text-md: 15px;
    --text-lg: 18px;
    --text-xl: 22px;
    --text-2xl: 26px;
    --line-height-base: 1.55;

    /* Spacing Scale */
    --space-1: 4px;
    --space-2: 8px;
    --space-3: 12px;
    --space-4: 16px;
    --space-5: 20px;
    --space-6: 24px;
    --space-8: 32px;

    /* Radii */
    --radius-sm: 3px;
    --radius-md: 5px;
    --radius-lg: 8px;

    /* Shadows */
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 2px 4px -1px rgba(0, 0, 0, 0.06), 0 1px 2px -1px rgba(0, 0, 0, 0.04);
    --shadow-book: 0 3px 6px -1px rgba(0, 0, 0, 0.12), 0 2px 4px -2px rgba(0, 0, 0, 0.08);
    --shadow-book-hover: 0 6px 12px -2px rgba(0, 0, 0, 0.16), 0 3px 6px -3px rgba(0, 0, 0, 0.1);

    /* Accessible Focus Ring */
    --focus-ring: 0 0 0 3px rgba(3, 105, 161, 0.35);
}

/* --------------------------------------------------------------------------
   2. Resets, Base Elements & Accessibility
   -------------------------------------------------------------------------- */
*, *::before, *::after {
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

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

body {
    margin: 0;
    padding: 0;
    background-color: var(--color-bg);
    color: var(--color-text-body);
    font-family: var(--font-sans);
    font-size: var(--text-base);
    line-height: var(--line-height-base);
    -webkit-font-smoothing: antialiased;
}

/* Accessible Skip Link */
.skip-link {
    position: absolute;
    top: -40px;
    left: 10px;
    background: var(--color-primary);
    color: #ffffff;
    padding: 8px 14px;
    z-index: 10000;
    font-size: var(--text-sm);
    font-weight: bold;
    text-decoration: none;
    border-radius: var(--radius-sm);
    transition: top 0.15s ease-in-out;
}

.skip-link:focus {
    top: 10px;
    outline: var(--focus-ring);
}

/* Centered Layout Containers */
.site-container {
    max-width: 980px;
    margin: 0 auto;
    padding: 16px 20px 48px 20px;
}

/* Hyperlinks */
a {
    color: var(--color-link);
    text-decoration: underline;
    text-underline-offset: 2px;
    transition: color 0.15s ease-in-out;
}

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

a:focus-visible {
    outline: var(--focus-ring);
    border-radius: var(--radius-sm);
}

/* Typography Headings */
h1 {
    font-size: var(--text-xl);
    font-weight: 700;
    margin: 0 0 12px 0;
    color: var(--color-text);
    line-height: 1.3;
}

h2 {
    font-size: var(--text-lg);
    font-weight: 700;
    margin: 24px 0 12px 0;
    border-bottom: 1px solid var(--color-border);
    padding-bottom: 6px;
    color: var(--color-text);
}

h3 {
    font-size: var(--text-md);
    font-weight: 700;
    margin: 16px 0 8px 0;
    color: var(--color-text);
}

p {
    margin: 0 0 12px 0;
}

/* --------------------------------------------------------------------------
   3. Header, Brand & Navigation
   -------------------------------------------------------------------------- */
header.site-header {
    border-bottom: 2px solid var(--color-text);
    padding-bottom: 14px;
    margin-bottom: 24px;
}

.brand-section {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 12px;
}

.site-title {
    font-size: var(--text-2xl);
    font-weight: 800;
    margin: 0;
    letter-spacing: -0.5px;
}

.site-title a {
    color: var(--color-text);
    text-decoration: none;
}

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

.site-tagline {
    font-size: var(--text-sm);
    color: var(--color-text-muted);
    margin: 2px 0 0 0;
    font-weight: 500;
}

/* Header Search */
.header-search {
    display: flex;
    align-items: center;
}

.site-search-form {
    display: flex;
    gap: 6px;
    align-items: center;
}

.site-search-input {
    width: 270px;
    font-size: var(--text-sm);
    padding: 6px 10px;
    border: 1px solid var(--color-border-dark);
    border-radius: var(--radius-sm);
    background-color: var(--color-bg);
    color: var(--color-text);
}

.site-search-input:focus {
    border-color: var(--color-primary);
    outline: none;
    box-shadow: var(--focus-ring);
}

.site-search-btn {
    font-size: var(--text-sm);
    padding: 6px 12px;
    background-color: var(--color-primary);
    color: #ffffff;
    border: 1px solid var(--color-primary-hover);
    cursor: pointer;
    border-radius: var(--radius-sm);
    font-weight: 600;
    transition: background-color 0.15s ease;
}

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

.site-search-btn:focus-visible {
    outline: var(--focus-ring);
}

/* Navigation Bar */
nav.site-nav {
    margin-top: 12px;
    padding: 8px 0;
    border-top: 1px solid var(--color-border-light);
    font-size: var(--text-sm);
}

nav.site-nav ul {
    list-style: none;
    margin: 0;
    padding: 0;
    display: flex;
    flex-wrap: wrap;
    gap: 16px;
    align-items: center;
}

nav.site-nav li {
    display: inline;
}

nav.site-nav a {
    color: var(--color-text-body);
    text-decoration: none;
    font-weight: 500;
    padding: 4px 6px;
    border-radius: var(--radius-sm);
    transition: color 0.15s ease, background-color 0.15s ease;
}

nav.site-nav a:hover {
    color: var(--color-primary);
    background-color: var(--color-primary-light);
    text-decoration: none;
}

nav.site-nav a.active {
    color: var(--color-primary);
    font-weight: 700;
    border-bottom: 2px solid var(--color-primary);
    border-radius: 0;
}

/* Mobile Nav Toggle Button */
.nav-toggle-btn {
    display: none;
    background: transparent;
    border: 1px solid var(--color-border);
    padding: 6px 10px;
    border-radius: var(--radius-sm);
    cursor: pointer;
    font-size: var(--text-sm);
    font-weight: 600;
    color: var(--color-text);
}

.nav-toggle-btn:focus-visible {
    outline: var(--focus-ring);
}

/* Breadcrumbs */
.breadcrumbs {
    font-size: var(--text-sm);
    color: var(--color-text-muted);
    margin-bottom: 18px;
    padding-bottom: 8px;
    border-bottom: 1px dotted var(--color-border);
}

.breadcrumbs a {
    color: var(--color-link);
    text-decoration: none;
}

.breadcrumbs a:hover {
    text-decoration: underline;
}

/* --------------------------------------------------------------------------
   4. Buttons & Interactive Controls
   -------------------------------------------------------------------------- */
.btn {
    font-size: var(--text-sm);
    font-weight: 600;
    padding: 7px 14px;
    background-color: #f1f5f9;
    color: var(--color-text);
    border: 1px solid var(--color-border-dark);
    border-radius: var(--radius-sm);
    cursor: pointer;
    text-decoration: none;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 6px;
    line-height: 1.3;
    transition: background-color 0.15s ease, border-color 0.15s ease, box-shadow 0.15s ease;
}

.btn:hover {
    background-color: #e2e8f0;
    color: var(--color-text);
    text-decoration: none;
}

.btn:focus-visible {
    outline: var(--focus-ring);
}

.btn-primary {
    background-color: var(--color-primary);
    color: #ffffff !important;
    border-color: var(--color-primary-hover);
}

.btn-primary:hover {
    background-color: var(--color-primary-hover);
    color: #ffffff !important;
}

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

.btn-accent:hover {
    background-color: var(--color-accent-hover);
    color: #ffffff !important;
}

.btn-success {
    background-color: var(--color-success);
    color: #ffffff !important;
    border-color: #14532d;
}

.btn-success:hover {
    background-color: #166534;
    color: #ffffff !important;
}

.btn-danger {
    background-color: var(--color-danger);
    color: #ffffff !important;
    border-color: #991b1b;
}

.btn-danger:hover {
    background-color: #991b1b;
    color: #ffffff !important;
}

.btn-amazon {
    background-color: var(--color-amazon);
    color: var(--color-amazon-dark) !important;
    border-color: var(--color-amazon-hover);
    font-weight: 700;
}

.btn-amazon:hover {
    background-color: var(--color-amazon-hover);
    color: var(--color-amazon-dark) !important;
}

.btn-secondary {
    background-color: #f1f5f9;
    color: var(--color-text);
    border: 1px solid var(--color-border-dark);
}

.btn-secondary:hover {
    background-color: #e2e8f0;
    color: var(--color-text);
}

/* Backward-compatible .button aliases */
.button {
    font-size: var(--text-sm);
    font-weight: 600;
    padding: 7px 14px;
    background-color: #f1f5f9;
    color: var(--color-text);
    border: 1px solid var(--color-border-dark);
    border-radius: var(--radius-sm);
    cursor: pointer;
    text-decoration: none;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 6px;
    line-height: 1.3;
    transition: background-color 0.15s ease, border-color 0.15s ease;
}

.button:hover {
    background-color: #e2e8f0;
    color: var(--color-text);
    text-decoration: none;
}

.button-primary {
    background-color: var(--color-primary);
    color: #ffffff !important;
    border-color: var(--color-primary-hover);
}

.button-primary:hover {
    background-color: var(--color-primary-hover);
    color: #ffffff !important;
}

.button-secondary {
    background-color: #f1f5f9;
    color: var(--color-text);
    border-color: var(--color-border-dark);
}

.button-secondary:hover {
    background-color: #e2e8f0;
    color: var(--color-text);
}

.button-danger {
    background-color: var(--color-danger);
    color: #ffffff !important;
    border-color: #991b1b;
}

.button-danger:hover {
    background-color: #991b1b;
    color: #ffffff !important;
}

.button-sm {
    padding: 4px 8px;
    font-size: var(--text-xs);
}

.btn-sm {
    padding: 4px 8px;
    font-size: var(--text-xs);
}

.btn-lg {
    padding: 10px 20px;
    font-size: var(--text-base);
}

/* --------------------------------------------------------------------------
   5. Standardized Book Card Grid & Components
   -------------------------------------------------------------------------- */
.book-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
    gap: 20px;
    margin: 20px 0 30px 0;
}

.book-card {
    background: var(--color-bg);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    overflow: hidden;
    display: flex;
    flex-direction: column;
    transition: transform 0.15s ease, box-shadow 0.15s ease, border-color 0.15s ease;
}

.book-card:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-book-hover);
    border-color: var(--color-border-dark);
}

.book-card:focus-within {
    outline: var(--focus-ring);
}

.book-cover-wrap {
    position: relative;
    width: 100%;
    aspect-ratio: 2 / 3;
    background: var(--color-bg-subtle);
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
    border-bottom: 1px solid var(--color-border-light);
    text-decoration: none;
}

.book-cover-img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    display: block;
    transition: transform 0.2s ease;
}

.book-card:hover .book-cover-img {
    transform: scale(1.02);
}

/* Elegant Typographic Cover Placeholder */
.book-cover-placeholder {
    width: 100%;
    height: 100%;
    background: linear-gradient(135deg, #f8fafc 0%, #e2e8f0 100%);
    box-shadow: inset 5px 0 8px -3px rgba(0, 0, 0, 0.12);
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    padding: 14px 12px;
    text-align: center;
    color: var(--color-text);
}

.book-cover-icon {
    font-size: 24px;
    opacity: 0.85;
    margin: 6px auto 0 auto;
}

.book-cover-title {
    font-size: var(--text-xs);
    font-weight: 700;
    line-height: 1.35;
    color: var(--color-text);
    display: -webkit-box;
    -webkit-line-clamp: 4;
    -webkit-box-orient: vertical;
    overflow: hidden;
    margin: 8px 0;
}

.book-cover-author {
    font-size: 10px;
    color: var(--color-text-muted);
    font-weight: 600;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.book-cover-badge {
    position: absolute;
    top: 8px;
    right: 8px;
    font-size: 10px;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    padding: 2px 6px;
    border-radius: var(--radius-sm);
    box-shadow: var(--shadow-sm);
}

.book-card-body {
    padding: 12px 14px;
    display: flex;
    flex-direction: column;
    flex: 1;
}

.book-card-title {
    font-size: var(--text-base);
    font-weight: 700;
    margin: 0 0 4px 0;
    line-height: 1.35;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.book-card-title a {
    color: var(--color-text);
    text-decoration: none;
}

.book-card-title a:hover {
    color: var(--color-primary);
    text-decoration: underline;
}

.book-card-author {
    font-size: var(--text-sm);
    color: var(--color-text-muted);
    margin: 0 0 8px 0;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.book-card-author a {
    color: var(--color-text-muted);
    text-decoration: none;
}

.book-card-author a:hover {
    color: var(--color-link);
    text-decoration: underline;
}

.book-card-meta {
    margin-top: auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: var(--text-xs);
    color: var(--color-text-light);
    border-top: 1px dotted var(--color-border-light);
    padding-top: 8px;
}

/* --------------------------------------------------------------------------
   6. Search Page, Filters, Highlighting & Autocomplete
   -------------------------------------------------------------------------- */
.search-box-container {
    background-color: var(--color-bg-subtle);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    padding: 16px 20px;
    margin-bottom: 25px;
}

.search-box-container h2 {
    font-size: var(--text-md);
    margin: 0 0 10px 0;
    border: none;
    padding: 0;
}

.search-form {
    display: flex;
    gap: 8px;
}

.search-input {
    flex: 1;
    font-size: var(--text-base);
    padding: 8px 12px;
    border: 1px solid var(--color-border-dark);
    border-radius: var(--radius-sm);
    background-color: var(--color-bg);
    color: var(--color-text);
}

.search-input:focus {
    border-color: var(--color-primary);
    outline: none;
    box-shadow: var(--focus-ring);
}

.search-form-advanced {
    background-color: var(--color-bg-subtle);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    padding: 14px 18px;
    margin-bottom: 20px;
}

.search-input-row {
    display: flex;
    gap: 8px;
    margin-bottom: 12px;
}

.search-filters-bar {
    display: flex;
    flex-wrap: wrap;
    gap: 14px;
    align-items: center;
    font-size: var(--text-sm);
    border-top: 1px solid var(--color-border-light);
    padding-top: 12px;
}

.filter-group {
    display: flex;
    align-items: center;
    gap: 6px;
}

.filter-group label {
    font-weight: 600;
    color: var(--color-text-muted);
}

.filter-select {
    font-size: var(--text-sm);
    padding: 5px 8px;
    border: 1px solid var(--color-border-dark);
    border-radius: var(--radius-sm);
    background-color: var(--color-bg);
    color: var(--color-text);
}

.filter-select:focus {
    outline: none;
    border-color: var(--color-primary);
    box-shadow: var(--focus-ring);
}

.filter-input-small {
    width: 68px;
    font-size: var(--text-sm);
    padding: 4px 6px;
    border: 1px solid var(--color-border-dark);
    border-radius: var(--radius-sm);
}

.filter-chip {
    background-color: #eef3f8;
    border: 1px solid #ccd8e4;
    padding: 3px 8px;
    border-radius: var(--radius-sm);
    display: inline-flex;
    align-items: center;
    gap: 6px;
    font-size: var(--text-xs);
    color: var(--color-text);
}

.filter-chip-remove {
    color: var(--color-danger);
    text-decoration: none;
    font-weight: bold;
    font-size: 14px;
}

.notice-suggestion {
    background-color: var(--color-info-bg);
    border-left: 4px solid var(--color-accent);
    padding: 12px 16px;
    margin-bottom: 18px;
    font-size: var(--text-sm);
    border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
}

.search-highlight {
    background-color: #fef08a;
    color: #111111;
    padding: 0 2px;
    border-radius: 2px;
}

/* Autocomplete Container & Dropdown */
.autocomplete-container {
    position: relative;
    display: flex;
}

.search-suggestions-dropdown {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    min-width: 320px;
    background: #ffffff;
    border: 1px solid var(--color-border-dark);
    border-radius: 0 0 var(--radius-md) var(--radius-md);
    box-shadow: 0 4px 16px rgba(0, 0, 0, 0.15);
    z-index: 1000;
    margin-top: 2px;
    max-height: 380px;
    overflow-y: auto;
    text-align: left;
}

.ac-item {
    display: flex;
    align-items: flex-start;
    padding: 9px 12px;
    border-bottom: 1px solid var(--color-border-light);
    text-decoration: none;
    color: var(--color-text);
    gap: 10px;
    font-size: var(--text-sm);
    cursor: pointer;
}

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

.ac-item.active, .ac-item:hover {
    background-color: var(--color-primary-light);
    color: var(--color-primary);
}

.ac-badge {
    font-size: 10px;
    text-transform: uppercase;
    padding: 1px 5px;
    border: 1px solid var(--color-border);
    background: #f8f8f8;
    color: var(--color-text-muted);
    white-space: nowrap;
    border-radius: 2px;
    margin-top: 2px;
}

.ac-content {
    display: flex;
    flex-direction: column;
    overflow: hidden;
    flex: 1;
}

.ac-title {
    font-weight: 700;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.ac-sub {
    font-size: var(--text-xs);
    color: var(--color-text-muted);
    margin-top: 2px;
}

/* --------------------------------------------------------------------------
   7. Tables (Metadata & Administration)
   -------------------------------------------------------------------------- */
.table-responsive {
    display: block;
    width: 100%;
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
}

table.meta-table, table.admin-table {
    width: 100%;
    border-collapse: collapse;
    margin: 15px 0 20px 0;
    font-size: var(--text-sm);
    background-color: var(--color-bg);
}

table.meta-table th, table.meta-table td,
table.admin-table th, table.admin-table td {
    border: 1px solid var(--color-border);
    padding: 8px 12px;
    text-align: left;
    vertical-align: middle;
}

table.meta-table th, table.admin-table th {
    background-color: var(--color-bg-subtle);
    font-weight: 700;
    color: var(--color-text);
    font-size: var(--text-xs);
    text-transform: uppercase;
    letter-spacing: 0.3px;
}

table.admin-table tr:hover {
    background-color: #f8fafc;
}

/* --------------------------------------------------------------------------
   8. Document Listings (Compact / Search List)
   -------------------------------------------------------------------------- */
.document-list {
    list-style: none;
    margin: 0;
    padding: 0;
}

.document-item {
    padding: 14px 0;
    border-bottom: 1px dotted var(--color-border);
    display: flex;
    gap: 16px;
    align-items: flex-start;
}

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

.document-item-thumb {
    width: 60px;
    aspect-ratio: 2 / 3;
    flex-shrink: 0;
    border: 1px solid var(--color-border);
    border-radius: var(--radius-sm);
    overflow: hidden;
    background: var(--color-bg-subtle);
}

.document-item-thumb img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    display: block;
}

.document-item-content {
    flex: 1;
}

.document-title {
    font-size: var(--text-md);
    font-weight: 700;
    margin-bottom: 4px;
}

.document-title a {
    color: var(--color-text);
    text-decoration: none;
}

.document-title a:hover {
    color: var(--color-primary);
    text-decoration: underline;
}

.document-meta {
    font-size: var(--text-xs);
    color: var(--color-text-muted);
    margin-bottom: 6px;
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: 6px;
}

.document-snippet {
    font-size: var(--text-sm);
    color: var(--color-text-body);
    line-height: 1.45;
}

/* --------------------------------------------------------------------------
   9. Directory & Category Grid
   -------------------------------------------------------------------------- */
.directory-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
    gap: 16px;
    margin: 16px 0 28px 0;
}

.directory-category {
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    padding: 14px 16px;
    background-color: var(--color-bg-subtle);
    transition: border-color 0.15s ease, box-shadow 0.15s ease;
}

.directory-category:hover {
    border-color: var(--color-primary);
    box-shadow: var(--shadow-sm);
}

.directory-category h3 {
    margin: 0 0 6px 0;
    font-size: var(--text-base);
}

.directory-category h3 a {
    color: var(--color-text);
    text-decoration: none;
}

.directory-category h3 a:hover {
    color: var(--color-primary);
    text-decoration: underline;
}

/* --------------------------------------------------------------------------
   10. Badges, Notices & Alerts
   -------------------------------------------------------------------------- */
.badge {
    display: inline-flex;
    align-items: center;
    padding: 2px 7px;
    font-size: var(--text-xs);
    font-weight: 700;
    border-radius: var(--radius-sm);
    line-height: 1.2;
}

.badge-success { background: var(--color-success-bg); color: var(--color-success); border: 1px solid var(--color-success-border); }
.badge-warning { background: var(--color-warning-bg); color: var(--color-warning); border: 1px solid var(--color-warning-border); }
.badge-danger  { background: var(--color-danger-bg);  color: var(--color-danger);  border: 1px solid var(--color-danger-border); }
.badge-info    { background: var(--color-info-bg);    color: var(--color-info);    border: 1px solid var(--color-info-border); }
.badge-neutral { background: #f1f5f9;                 color: var(--color-text-muted); border: 1px solid var(--color-border); }

.badge-status {
    font-size: 10px;
    padding: 2px 6px;
    border-radius: 2px;
    text-transform: uppercase;
    letter-spacing: 0.3px;
    display: inline-block;
}

.badge-verified {
    background-color: var(--color-success-bg);
    color: var(--color-success);
    border: 1px solid var(--color-success-border);
    font-weight: 700;
}

.badge-unverified {
    background-color: #f4f4f4;
    color: #555555;
    border: 1px solid #dcdcdc;
}

.badge-external {
    background-color: var(--color-warning-bg);
    color: var(--color-warning);
    border: 1px solid var(--color-warning-border);
}

.notice-box {
    border: 1px solid var(--color-border);
    background-color: var(--color-bg-subtle);
    padding: 14px 18px;
    margin: 18px 0;
    font-size: var(--text-sm);
    border-radius: var(--radius-sm);
}

.notice-box.warning {
    border-color: var(--color-warning-border);
    background-color: var(--color-warning-bg);
    color: #78350f;
}

.alert-success {
    background: var(--color-success-bg);
    border: 1px solid var(--color-success-border);
    color: var(--color-success);
    padding: 10px 14px;
    margin-bottom: 16px;
    border-radius: var(--radius-sm);
    font-weight: 600;
    font-size: var(--text-sm);
}

.alert-error, .alert-danger {
    background: var(--color-danger-bg);
    border: 1px solid var(--color-danger-border);
    color: var(--color-danger);
    padding: 10px 14px;
    margin-bottom: 16px;
    border-radius: var(--radius-sm);
    font-weight: 600;
    font-size: var(--text-sm);
}

/* --------------------------------------------------------------------------
   11. Advertising Placements
   -------------------------------------------------------------------------- */
.ad-placement-box {
    margin: 20px 0;
    padding: 10px;
    border: 1px solid var(--color-border-light);
    background-color: var(--color-bg-subtle);
    border-radius: var(--radius-sm);
    text-align: center;
}

.ad-disclosure-label {
    display: block;
    font-size: 10px;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    color: var(--color-text-light);
    margin-bottom: 6px;
}

.ad-content {
    min-height: 50px;
    display: flex;
    justify-content: center;
    align-items: center;
}

.ad-fallback-text {
    font-size: var(--text-sm);
    color: var(--color-text-muted);
    padding: 6px 0;
    text-align: center;
}

/* --------------------------------------------------------------------------
   12. Pagination
   -------------------------------------------------------------------------- */
.pagination {
    margin: 28px 0 14px 0;
    font-size: var(--text-sm);
    display: flex;
    align-items: center;
    flex-wrap: wrap;
    gap: 4px;
}

.pagination span, .pagination a {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-width: 32px;
    height: 32px;
    padding: 0 10px;
    border: 1px solid var(--color-border);
    border-radius: var(--radius-sm);
    text-decoration: none;
    color: var(--color-text-body);
    font-weight: 500;
}

.pagination a:hover {
    background-color: var(--color-primary-light);
    border-color: var(--color-primary);
    color: var(--color-primary);
}

.pagination span.current {
    background-color: var(--color-primary);
    color: #ffffff;
    border-color: var(--color-primary);
    font-weight: 700;
}

/* --------------------------------------------------------------------------
   13. Footer
   -------------------------------------------------------------------------- */
footer.site-footer {
    border-top: 1px solid var(--color-border);
    margin-top: 48px;
    padding-top: 20px;
    font-size: var(--text-sm);
    color: var(--color-text-muted);
    line-height: 1.6;
}

.footer-nav {
    margin-bottom: 12px;
    display: flex;
    flex-wrap: wrap;
    gap: 14px;
}

.footer-nav a {
    color: var(--color-text-muted);
    text-decoration: none;
    font-weight: 500;
}

.footer-nav a:hover {
    color: var(--color-primary);
    text-decoration: underline;
}

.footer-disclosure {
    font-size: var(--text-xs);
    color: var(--color-text-light);
    margin-top: 12px;
    border-top: 1px dotted var(--color-border-light);
    padding-top: 8px;
}

/* --------------------------------------------------------------------------
   Book Detail Showcase Layout
   -------------------------------------------------------------------------- */
.book-detail-hero {
    display: grid;
    grid-template-columns: 240px 1fr;
    gap: 30px;
    margin: 20px 0 30px 0;
    align-items: start;
}

.book-detail-sidebar {
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.book-detail-cover {
    width: 100%;
    aspect-ratio: 2 / 3;
    background: var(--color-bg-subtle);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-book);
    overflow: hidden;
    position: relative;
    display: flex;
    align-items: center;
    justify-content: center;
}

.book-detail-cover img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    display: block;
}

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

.book-detail-actions .btn {
    width: 100%;
    justify-content: center;
    text-align: center;
    box-sizing: border-box;
}

.book-detail-main {
    display: flex;
    flex-direction: column;
}

.book-detail-title {
    font-size: var(--text-2xl);
    font-family: var(--font-serif);
    font-weight: 700;
    color: var(--color-text);
    line-height: 1.25;
    margin: 0 0 10px 0;
}

.book-detail-author {
    font-size: var(--text-md);
    color: var(--color-text-muted);
    margin: 0 0 14px 0;
}

.book-detail-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    align-items: center;
    margin-bottom: 20px;
}

.book-synopsis-box {
    background: var(--color-bg);
    border: 1px solid var(--color-border);
    border-left: 3px solid var(--color-primary);
    border-radius: var(--radius-sm);
    padding: 16px 20px;
    margin-bottom: 20px;
    line-height: 1.6;
    color: var(--color-text);
    font-size: var(--text-base);
}

/* --------------------------------------------------------------------------
   14. Responsive Layout Adaptations
   -------------------------------------------------------------------------- */
@media (max-width: 768px) {
    .book-detail-hero {
        grid-template-columns: 1fr;
        gap: 20px;
    }

    .book-detail-cover {
        max-width: 220px;
        margin: 0 auto;
    }

    .site-container {
        padding: 12px 16px 40px 16px;
    }

    .brand-section {
        flex-direction: column;
        align-items: stretch;
    }

    .header-search {
        margin-top: 8px;
        width: 100%;
    }

    .site-search-form {
        width: 100%;
    }

    .site-search-input {
        width: 100%;
    }

    .nav-toggle-btn {
        display: inline-block;
        margin-top: 8px;
    }

    nav.site-nav {
        display: none;
    }

    nav.site-nav.open {
        display: block;
    }

    nav.site-nav ul {
        flex-direction: column;
        align-items: stretch;
        gap: 8px;
    }

    nav.site-nav li a {
        display: block;
        padding: 8px 10px;
    }

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

    .search-input-row {
        flex-direction: column;
    }

    .search-filters-bar {
        flex-direction: column;
        align-items: stretch;
    }

    .filter-group {
        justify-content: space-between;
    }

    .filter-select {
        max-width: none;
        flex: 1;
    }

    table.meta-table th, table.meta-table td {
        padding: 6px 8px;
    }
}

@media (max-width: 480px) {
    .site-title {
        font-size: 22px;
    }

    .book-grid {
        grid-template-columns: 1fr;
    }

    .document-item {
        flex-direction: column;
    }

    .document-item-thumb {
        width: 100px;
    }

    .directory-grid {
        grid-template-columns: 1fr;
    }
}

/* --------------------------------------------------------------------------
   15. Print Media Styles
   -------------------------------------------------------------------------- */
@media print {
    body {
        font-size: 11pt;
        color: #000000;
        background: #ffffff;
    }

    .site-container {
        max-width: 100%;
        padding: 0;
    }

    .skip-link, nav.site-nav, .search-box-container, .header-search,
    .ad-placement-box, footer.site-footer, .nav-toggle-btn, .btn {
        display: none !important;
    }

    a {
        text-decoration: none;
        color: #000000;
    }
}